氏名

カワニシ テツヤ

川西 哲也

職名

教授 (https://researchmap.jp/read0006160)

所属

(基幹理工学部)

連絡先

URL等

研究者番号
40359063

本属以外の学内所属

兼担

理工学術院(大学院基幹理工学研究科)

学内研究所等

熱エネルギー変換工学・数学融合研究所

研究所員 2017年-

理工学術院総合研究所(理工学研究所)

兼任研究員 2018年-

学歴・学位

学歴

1988年04月-1992年03月 京都大学 工学部 電子工学科
1992年04月-1994年03月 京都大学 大学院工学研究科 電子工学専攻
1995年10月-1997年07月 京都大学 大学院工学研究科 電子通信工学専攻

学位

博士(工学) 課程 京都大学

経歴

1994年01月-1995年09月松下電器産業株式会社生産技術本部生産技術研究所
1997年07月-1998年03月京都大学ベンチャービジネスラボラトリー
1998年04月-通信総合研究所(現 情報通信研究機構)
2003年12月-2004年05月カリフォルニア大学サンディエゴ校電子情報学科客員研究員
2015年04月-早稲田大学理工学術院基幹理工学部電子物理システム学科

所属学協会

米国電気通信学会 (IEEE) フェロー

電子情報通信学会 会員

応用物理学会 会員

取材ガイド

カテゴリー
工学
専門分野
光通信技術、ミリ波技術、光と電波の融合
自己紹介コメント
専門は電気信号を光信号に変換する部分である光変調に関連する分野。スピードだけではなく、圧倒的な正確さにこだわるというスタイルで研究を進めてきた。精度の高さが生かされた分野としては電波天文への応用が挙げられ、世界最大の電波望遠鏡ALMAの基準光信号にも使用されている。最近では滑走路や線路の安全を監視するためのレーダーシステムにも応用を進めている。2015年まで情報通信研究機構光通信基盤研究室長。IEEEフェロー。総務省異能vation スーパーバイザー。経済産業省グローバルコーディネーター。
キーワード
光デバイス、計測技術、レーダー

論文

High Extinction-Ratio Integrated Mach-Zehnder Modulator With Active Y-Branch for Optical SSB Signal Generation

Ogiso, Yoshihiro;Tsuchiya, Yuta;Shinada, Satoshi;Nakajima, Shinya;Kawanishi, Tetsuya;Nakajima, Hirochika

IEEE PHOTONICS TECHNOLOGY LETTERS22(12)p.941 - 9432010年-2010年

DOIWoS

詳細

ISSN:1041-1135

Monolithic mode-locked erbium-doped LiNbO3 waveguide laser with dielectric multilayer mirror

Katano, Yutaro;Shinada, Satoshi;Nakajima, Shinya;Kawanishi, Tetsuya;Nakajima, Hirochika

IEICE ELECTRONICS EXPRESS9(4)p.245 - 2492012年-2012年

DOIWoS

詳細

ISSN:1349-2543

Precise chirp parameter measurement of asymmetric Mach-Zehnder modulators with active Y-branch

Yamaguchi, Yuya;Yamada, Yuki;Kanno, Atsushi;Kawanishi, Tetsuya;Izutsu, Masayuki;Nakajima, Hirochika

IEICE ELECTRONICS EXPRESS10(12)2013年-2013年

DOIWoS

詳細

ISSN:1349-2543

Low-Crosstalk Balanced Bridge Interferometric-Type Optical Switch for Optical Signal Routing

Chiba, Akito;Kawanishi, Tetsuya;Sakamoto, Takahide;Higuma, Kaoru;Takada, Kazumasa;Izutsu, Masayuki

IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS19(6)2013年-2013年

DOIWoS

詳細

ISSN:1077-260X

High extinction ratio characteristics of over 60 dB Mach-Zehnder modulator with asymmetric power-splitting Y-branches on X-cut Ti:LiNbO3

Yamaguchi, Yuya;Nakajima, Shinya;Kanno, Atsushi;Kawanishi, Tetsuya;Izutsu, Masayuki;Nakajima, Hirochika

JAPANESE JOURNAL OF APPLIED PHYSICS53(8)2014年-2014年

DOIWoS

詳細

ISSN:0021-4922

Millimeter-Wave Radar Receiver Using Z-Cut LiNbO3 Optical Modulator with Orthogonal-Gap-Embedded Patch-Antennas on Low-k Dielectric Material

Wijayanto, Yusuf Nur;Kanno, Atsushi;Murata, Hiroshi;Kawanishi, Tetsuya;Okamura, Yasuyuki

IEICE TRANSACTIONS ON ELECTRONICSE98C(8)p.783 - 7922015年-2015年

DOIWoS

詳細

ISSN:1745-1353

Auミラーを用いた共振型LiNbO_3光変調器の高効率・小型化

高橋 優太;土屋 佑太;品田 聡;中島 慎也;川西 哲也;中島 啓幾

電気学会研究会資料. EMT, 電磁界理論研究会2010(62)p.33 - 362010年07月-2010年07月 

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並列型LiNbO_3光変調器のバイアス制御方法に関する検討(量子効果デバイス(光信号処理、LD、光増幅、変調等)と集積化技術、一般「材料デバイスサマーミーティング」)

土屋 佑太;坂本 高秀;川西 哲也;中島 啓幾

電子情報通信学会技術研究報告. OPE, 光エレクトロニクス110(102)p.31 - 352010年06月-2010年06月 

CiNii

詳細

ISSN:09135685

概要:我々のグループでは,LiNbO_3光変調器の基本構造となるマッハツェンダ型干渉構造の光入射側のY分岐部分に新たな電極を設置することで,光変調器の消光比を改善する報告を行った.今回これらの方法を多値変調技術に応用することを考え,並列型マッハツェンダ構造を有するLiNbO_3光変調器でのバイアス制御方法についてシミュレーションを行い確認した.また新たな電極構造を設置すると,その電極から発生する電界により光の位相変化が生じるため,その位相変化を考慮したバイアス制御方法が必要となる.本研究では実際にその位相変化の影響を実験によって確認し,その構造を並列型LiNbO_3光変調器の構造に導入するためのバイアス制御方法について検討した.

C-14-13 電界制御Y分岐LiNbO_3変調器によるTwo-tone光連続生成(C-14.マイクロ波フォトニクス,一般セッション)

土屋 佑太;小木曽 義弘;品田 聡;中島 慎也;川西 哲也;中島 啓幾

電子情報通信学会総合大会講演論文集2011(1)2011年02月-2011年02月 

CiNii

C-3-52 アクティブY分岐MZ型LiNbO_3変調器の高消光比化に向けた導波路構造(光変調器,C-3.光エレクトロニクス,一般セッション)

山口 祐也;中島 慎也;菅野 敦史;川西 哲也;中島 啓幾

電子情報通信学会ソサイエティ大会講演論文集2012(1)2012年08月-2012年08月 

CiNii

C-3-36 光コム生成用変調器のためのチャープパラメータ精密測定(C-3.光エレクトロニクス)

山田 悠實;山口 祐也;井筒 雅之;菅野 敦史;川西 哲也;中島 啓幾

電子情報通信学会総合大会講演論文集2013(1)2013年03月-2013年03月 

CiNii

C-3-37 後方入射光を用いた高消光比LN変調器のバイアス制御(C-3.光エレクトロニクス)

田中 将規;菅野 敦史;川西 哲也;井筒 雅之;中島 啓幾

電子情報通信学会総合大会講演論文集2013(1)2013年03月-2013年03月 

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干渉型光スイッチの高周波領域クロストークの評価および光強度トリマ構造による抑圧(光-無線融合NW、新周波数(波長)帯デバイス、フォトニックNW・デバイス、フォトニック結晶、ファイバとその応用、光集積回路、光導波路素子、光スイッチング、導波路解析、一般)

千葉 明人;川西 哲也;坂本 高秀;日隈 薫;高田 和正;井筒 雅之

電子情報通信学会技術研究報告. PN, フォトニックネットワーク113(393)p.321 - 3242014年01月-2014年01月 

CiNii

詳細

ISSN:09135685

概要:本稿では、高周波信号により駆動された干渉型光スイッチのクロストークを評価する手法について述べる。光スイッチのドロップポートの出力に含まれるキャリア成分を利用するもので、時間領域測定における光検出器の利得帯域幅積の制約を回避することが可能である。この手法を用いて、干渉型光スイッチの各アームにマッハツェンダー構造を入れ子にした2x2光スイッチのクロストークを実験的に評価した結果も報告する。

C-3-20 折り返し位相整合を用いた低電圧駆動LiNbO_3光変調器(光変調器,C-3.光エレクトロニクス,一般セッション)

飯村 鉄人;中島 慎也;菅野 敦史;川西 哲也;中島 啓幾;井筒 雅之

電子情報通信学会総合大会講演論文集2014(1)2014年03月-2014年03月 

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C-3-21 3倍波を重畳した光SSB-SC変調による高調波成分抑圧比の改善(光変調器,C-3.光エレクトロニクス,一般セッション)

中尾 亮太;山口 祐也;菅野 敦史;川西 哲也;井筒 雅之;中島 啓幾

電子情報通信学会総合大会講演論文集2014(1)2014年03月-2014年03月 

CiNii

C-3-70 消光比及びチャープ可変マッハ・ツェンダ光変調器(光変調器,C-3.光エレクトロニクス,一般セッション)

山口 祐也;中島 慎也;菅野 敦史;川西 哲也;井筒 雅之;中島 啓幾

電子情報通信学会総合大会講演論文集2015(1)2015年02月-2015年02月 

CiNii

C-14-17 微小ギャップを設けたパッチアンテナ電気光学変調器の積層化による変調効率の向上(C-14.マイクロ波・ミリ波フォトニクス,一般セッション)

綾 拡範;Wijayanto Yusuf Nur;菅野 敦史;川西 哲也;村田 博司;岡村 康行

電子情報通信学会ソサイエティ大会講演論文集2015(1)2015年08月-2015年08月 

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B-2-17 空港面異物検知レーダーによる鳥の検出の試み(B-2.宇宙・航行エレクトロニクス,一般セッション)

米本 成人;柴垣 信彦;加島 謙一;原本 亮喜;佐藤 洋介;稲垣 恵三;川西 哲也

電子情報通信学会ソサイエティ大会講演論文集2015(1)2015年08月-2015年08月 

CiNii

B-10-24 ループアシスト型コヒーレント整合受信器による時間周波数多重信号の一括チャネル分離測定(B-10.光通信システムB(光通信方式,光通信機器,デバイスのシステム応用,光通信網・規格),一般セッション)

坂本 高秀;呂 國偉;川西 哲也

電子情報通信学会ソサイエティ大会講演論文集2015(2)2015年08月-2015年08月 

CiNii

C-3-33 薄膜LN基板を用いて低駆動電圧化・低チャープ化したアクティブY分岐集積MZ変調器(C-3.光エレクトロニクス,一般セッション)

山口 祐也;菅野 敦史;川西 哲也;井筒 雅之;中島 啓幾

電子情報通信学会総合大会講演論文集2016(1)2016年03月-2016年03月 

CiNii

C-4-1 光ファイバー無線応用に向けた無バイアス型UTC-PDの開発(C-4.レーザ・量子エレクトロニクス,一般セッション)

梅沢 俊匡;加島 謙一;菅野 敦史;赤羽 浩一;松本 敦;山本 直克;川西 哲也

電子情報通信学会総合大会講演論文集2016(1)2016年03月-2016年03月 

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C-14-4 ファイバ無線ネットワークによるW帯ミリ波信号IF over fiber伝送システムの検討(C-14.マイクロ波・ミリ波フォトニクス,一般セッション)

菅野 敦史;Dat Pham Tien;山本 直克;川西 哲也

電子情報通信学会総合大会講演論文集2016(1)2016年03月-2016年03月 

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C-14-5 2逓倍により生成された256QAM信号の変調精度評価(C-14.マイクロ波・ミリ波フォトニクス,一般セッション)

金田 直樹;米本 成人;川西 哲也

電子情報通信学会総合大会講演論文集2016(1)2016年03月-2016年03月 

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C-14-12 電気光学変調器による波長チャープ変調と光ファイバの波長分散を用いたチャープパラメータの測定(C-14.マイクロ波・ミリ波フォトニクス,一般セッション)

中村 亮太;山本 勝之;河合 正;榎原 晃;山本 直克;川西 哲也

電子情報通信学会総合大会講演論文集2016(1)2016年03月-2016年03月 

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C-14-13 電気光学変調器による波長チャープ変調を用いた3次相互変調歪補償の検討(C-14.マイクロ波・ミリ波フォトニクス,一般セッション)

前田 幸子;河合 正;榎原 晃;山本 直克;川西 哲也

電子情報通信学会総合大会講演論文集2016(1)2016年03月-2016年03月 

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C-14-14 電気光学変調器を用いた低変調指数動作での光周波数コム信号発生の検討(C-14.マイクロ波・ミリ波フォトニクス,一般セッション)

前田 直樹;中村 亮太;河合 正;榎原 晃;山本 直克;川西 哲也

電子情報通信学会総合大会講演論文集2016(1)2016年03月-2016年03月 

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B-10-45 2組の2トーン光信号を用いたコヒーレント光受信器における同相信号除去比の測定(B-10.光通信システムB(光通信方式,光通信機器,デバイスのシステム応用,光通信網・規格),一般セッション)

稲垣 惠三;川西 哲也;菅野 敦史;山本 直克

電子情報通信学会総合大会講演論文集2016(2)2016年03月-2016年03月 

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B-10-82 集積型偏波多重直交変調器による光位相共役信号対発生(B-10.光通信システムB(光通信方式,光通信機器,デバイスのシステム応用,光通信網・規格),一般セッション)

坂本 高秀;呂 國偉;山本 直克;川西 哲也

電子情報通信学会総合大会講演論文集2016(2)2016年03月-2016年03月 

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Sub-THz radio-over-fiber signal generation using external modulation

Kawanishi Tetsuya;Sakamoto Takahide;Kanno Atsushi

IEICE Electronics Express12(13)p.20152004 - 201520042015年-2015年

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詳細

ISSN:1349-2543

概要:This paper describes photonic technologies for millimeter-wave generation and distribution. External modulation would be useful for stable and high-quality radio-over-fiber signal generation, where frequency stability and spurious suppression are very important for radio services such as mobile communications, radio locations etc. This paper provides outline of radio-over-fiber signal generation techniques. Precise and high-speed lightwave optical modulation would play important roles for suppression of undesired spectrum components. Photonic harmonic generation would be useful for very high-frequency signals. Reciprocating optical modulators consisting of optical modulators and fiber Bragg gratings can provide optical modulation by sub-THz signals.

Radio-on-radio-over-fiber: Efficient fronthauling for small cells and moving cells

Dat, Pham Tien; Kanno, Atsushi; Kawanishi, Tetsuya

IEEE Wireless Communications22(5)p.67 - 752015年10月-2015年10月 

DOIScopus

詳細

ISSN:15361284

概要:© 2002-2012 IEEE. A combination of fiber and radio links would be attractive for efficient fronthauling to small cells and moving cells. However, achieving connectivity by using wired-wireless media converters significantly increases system complexity, power consumption, and latency. A seamless combination of fiber and radio links in which photonics-based technologies are used to generate and transmit radiowave signals is more suitable. In this article, we present an overview of fiber-radio link combination for mobile signal transmission. We propose an efficient solution for future mobile fronthauling based on the analog transmission of mobile signals over a bidirectional seamless system. We discuss the potential as well as the challenges and perspectives of the systems applied for mobile fronthauling in small-cell- and movingcell- based networks. We also present a proof-ofconcept demonstration of the transmission of mobile signals over the system. Satisfactory performance is obtained for different high-speed advanced signals. The transmission range over fiber links and the estimated range of the radio links are sufficiently long to facilitate the practical implementation of the system. The system is scalable to include new deployments of small cells and wireless services using wavelength-division and subcarrier multiplexing techniques. It can provide a high-speed, low-latency, and flexible solution for fronthauling in new emerging wireless systems such as 5G networks.

Pure single-sideband modulation using high extinction-ratio parallel Mach-Zehnder modulator with third-order harmonics superposition technique

Yamaguchi, Yuya; Kanno, Atsushi; Kawanishi, Tetsuya; Izutsu, Masayuki; Izutsu, Masayuki; Nakajima, Hirochika

Conference on Lasers and Electro-Optics Europe - Technical Digest2015-August2015年08月-2015年08月 

Scopus

詳細

概要:© 2015 OSA. We demonstrate high spurious suppression ratio single-sideband modulation by a high extinction-ratio parallel Mach-Zehnder modulator. An electrical third-order nonlinearity suppression technique can enhance the suppression ratio as high as 47 dB.

High-spectral efficiency millimeter wave-over-fiber system for future mobile fronthaul

Dat, Pham Tien; Kanno, Atsushi; Inagaki, Keizo; Yamamoto, Naokatsu; Kawanishi, Tetsuya; Kawanishi, Tetsuya

European Conference on Optical Communication, ECOC2015-November2015年11月-2015年11月 

DOIScopus

詳細

概要:© 2015 Viajes el Corte Ingles, VECISA.We present a high-spectral efficiency fronthaul system for the transmission of millimeter-wave and multiple-input multiple-output (MIMO) signals in future mobile networks. The transmission of an interband carrier aggregation and a 2 × 2 MIMO LTE-A signal over the system is successfully demonstrated.

Oppositely-biased dual-polarization IQ modulators for nonlinearity-tolerant polarization-multiplexed phase-conjugated twin-signals generation

Sakamoto, Takahide; Lu, Guo Wei; Lu, Guo Wei; Kawanishi, Tetsuya; Kawanishi, Tetsuya

European Conference on Optical Communication, ECOC2015-November2015年11月-2015年11月 

DOIScopus

詳細

概要:© 2015 Viajes el Corte Ingles, VECISA.We experimentally demonstrate generation of polarization-multiplexed phase-conjugated twin signals by using oppositely-biased dual-polarization IQ modulators, compensating for nonlinear signal distortion in fiber transmission. Bias condition is optimized investigating nonlinearity tolerance of the generated signals transmitted over SMF.

Array of patch-antennas with meandering-gaps on optical modulator for wireless millimeter-wave beam-steering

Wijayanto, Yusuf Nur; Wijayanto, Yusuf Nur; Kanno, Atsushi; Murata, Hiroshi; Kawanishi, Tetsuya; Kawanishi, Tetsuya; Yamamoto, Naokatsu; Okamura, Yasuyuki

International Journal of Microwave and Wireless Technologies8(4-5)p.759 - 7652016年06月-2016年06月 

DOIScopus

詳細

ISSN:17590787

概要:© Cambridge University Press and the European Microwave Association 2016.An array of patch-antennas with meandering-gaps on an optical modulator is proposed for wireless millimeter-wave beam-steering through high-speed radio-over-fiber systems. Wireless millimeter-wave can be received by the array of patch-antennas and directly modulated to lightwave by the optical modulator. The wireless millimeter-wave can be steered using the meandering-gaps at the patch-antennas by controlling interaction between millimeter-wave and lightwave electric fields in electro-optic modulation. The basic operation and analysis of the proposed device are discussed. In the experiment, 5 × 5 antenna array in 40 GHz millimeter-wave bands was designed and realized for device characterization and demonstration to wireless millimeter-wave beam-steering. There were five variations of wireless millimeter-wave beam-steering for one-dimensional in xz- or yz-planes that can be obtained with wireless millimeter-wave steerable beams of about ±30°. Additionally, 25 variations of wireless beam-steering can be obtained for two dimension in xyz-space through orthogonal optical modulation. The proposed device is promising to be applied in millimeter-wave/tera-hertz bands for future directional wireless communication and sensing with high-speed and high-resolution operation.

Laser-Phase-Fluctuation-Insensitive Optical Coherent Transmission of 16-Quadrature-Amplitude-Modulation Radio-Over-Fiber Signal

Kuri, Toshiaki; Sakamoto, Takahide; Kawanishi, Tetsuya; Kawanishi, Tetsuya

Journal of Lightwave Technology34(2)p.683 - 6902016年01月-2016年01月 

DOIScopus

詳細

ISSN:07338724

概要:© 1983-2012 IEEE.A laser-phase-fluctuation-insensitive optical coherent transmission of a 10-Gbaud 16-quadrture-amplitude-modulation radio-over-fiber signal with an offset-frequency-spaced two-tone local light and an digital-signal-processing technique is experimentally demonstrated. Error-free symbol recovery after the 20-km-long fiber-optic transmission is shown and the transmission quality is evaluated.

Full-Duplex Transmission of LTE-A Carrier Aggregation Signal over a Bidirectional Seamless Fiber-Millimeter-Wave System

Dat, Pham Tien; Kanno, Atsushi; Yamamoto, Naokatsu; Kawanishi, Tetsuya

Journal of Lightwave Technology34(2)p.691 - 7002016年01月-2016年01月 

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ISSN:07338724

概要:© 1983-2012 IEEE.We propose a flexible and high-performance fronthaul system for future mobile networks using a seamless combination of fiber-optic and millimeter-wave (MMW) systems. The proposed system employs a high-quality optical MMW signal generation at the transmitter and a stable and high-performance MMW self-homodyne detection at the receiver. In the downlink direction, successful transmission of intraband and interband carrier aggregation (CA) long-term evolution-advanced (LTE-A) signals over the system is experimentally confirmed. We also confirm satisfactory performance for the transmission over a fiber-wireless bridge using a cascade of the seamless system and a conventional radio-over-fiber (RoF) link. In the uplink direction, we successfully demonstrate the transmission of an intraband CA LTE-A signal over a cascade of a radio-on-radio and a RoF system. In addition, we confirm that the full-duplex transmission of LTE-A signals over the proposed bidirectional system does not experience performance degradation compared to the case with half-duplex transmission. The proposed system is a potential solution for mobile-signal transmission in future networks.

Fiber-remoted 96-GHz radar system

Kanno, Atsushi; Kawanishi, Tetsuya; Kawanishi, Tetsuya

2015 IEEE Avionics and Vehicle Fiber-Optics and Photonics Conference, AVFOP 2015p.59 - 602015年12月-2015年12月 

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概要:© 2015 IEEE.High-precision imaging technology and its application are highly demanded for the enhancement of civil security. They are used to help prevent major incidents in railways or airports. In these applications, both small object detection and high-range resolution are key features. As far as the detectable target size is concerned, a high-frequency carrier is indispensable in radar systems. However, a radio signal with millimeter-wave (high frequency) suffers from large atmospheric attenuation. For example, the attenuation coefficient at 90 GHz is estimated to be 1 dB/km, while it is less than 0.1 dB/km in microwave bands [1]. Thus, the radar signal will have to originate from an area close to the target. Setting up a radar system with a synthesizer close to the target might not be desirable because a high-precision electrical synthesizer is generally large and consumes high energy. Radio-over-fiber (RoF) technology, used to transport the signal over optical fibers, is a promising candidate to deliver the millimeter-wave signal to the suitable point over a low-loss optical fiber cable. Radars utilizing the RoF technology have already been reported; however, digital signal processing in remote radar heads was required to reduce large transmission data [2, 3].

Low-latency fiber-wireless bridge for flexible fronthauling in future mobile networks

Dat, Pham Tien; Kanno, Atsushi; Kawanishi, Tetsuya

European Microwave Week 2015:p.305 - 3082015年12月-2015年12月 

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概要:© 2015 EuMA.We propose a flexible and low-latency cascaded fiber-wireless system for future mobile fronthauling using seamless combination of fiber-optic and millimeter-wave links. Successful transmission of intraband and interband carrier aggregation LTE-A signals over the system is experimentally confirmed. Satisfactory performance is achieved owing to the use of a high-quality optical millimeter-wave signal generation technique at the transmitter and a proposed high-performance self-homodyne detection at the receiver.

Characteristics of highly stacked InAs quantum-dot laser grown on vicinal (001)InP substrate

Akahane, Kouichi; Umezawa, Toshimasa; Matsumoto, Atsushi; Yamamoto, Naokatsu; Kawanishi, Tetsuya; Kawanishi, Tetsuya

Japanese Journal of Applied Physics55(4)2016年04月-2016年04月 

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ISSN:00214922

概要:© 2016 The Japan Society of Applied Physics.We fabricate broad-area laser diodes consisting of 30-layer stacks of InAs quantum dots by using a strain-compensation technique on a vicinal (001)InP substrate. These laser diodes exhibit ground-state lasing at 1576nm in the pulsed mode with a high characteristic temperature of 111K at around room temperature (20-80 °C).

Heterogeneous quantum dot/silicon photonics-based wavelength-tunable laser diode with a 44 nm wavelength-tuning range

Kita, Tomohiro; Yamamoto, Naokatsu; Matsumoto, Atsushi; Kawanishi, Tetsuya; Kawanishi, Tetsuya; Yamada, Hirohito

Japanese Journal of Applied Physics55(4)2016年04月-2016年04月 

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ISSN:00214922

概要:© 2016 The Japan Society of Applied Physics.A heterogeneous wavelength-tunable laser diode combining quantum dot and silicon photonics technologies is proposed. A compact wavelengthtunable filter with two ring resonators was carefully designed and fabricated using silicon photonics technology. The tunable laser combining the wavelength-tunable filter and an optical amplifier, which includes InAs quantum dots, achieved a 44.0nm wavelength-tuning range at around 1250 nm. The broadband optical gain of the quantum dot optical amplifier was effectively used by the optimized wavelength-tunable filter. This heterogeneous wavelength-tunable laser diode could become a breakthrough technology for high-capacity data transmission systems.

Monolithically integrated quantum dot optical modulator with semiconductor optical amplifier for thousand and original band optical communication

Yamamoto, Naokatsu; Akahane, Kouichi; Umezawa, Toshimasa; Matsumoto, Atsushi; Kawanishi, Tetsuya; Kawanishi, Tetsuya

Japanese Journal of Applied Physics55(4)2016年04月-2016年04月 

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ISSN:00214922

概要:© 2016 The Japan Society of Applied Physics.A monolithically integrated quantum dot (QD) optical gain modulator (OGM) with a QD semiconductor optical amplifier (SOA) was successfully developed with T-band (1.0μm waveband) and O-band (1.3μm waveband) QD optical gain materials for Gbps-order, high-speed optical data generation. The insertion loss due to coupling between the device and the optical fiber was effectively compensated for by the SOA section. It was also confirmed that the monolithic QD-OGM/SOA device enabled >4.8 Gbps optical data generation with a clear eye opening in the T-band. Furthermore, we successfully demonstrated error-free 4.8 Gbps optical data transmissions in each of the six wavelength channels over a 10-kmlong photonic crystal fiber using the monolithic QD-OGM/SOA device in multiple O-band wavelength channels, which were generated by the single QD gain chip. These results suggest that the monolithic QD-OGM/SOA device will be advantageous in ultra-broadband optical frequency systems that utilize the T+O-band for short- and medium-range optical communications.

5G transport and broadband access networks: The need for new technologies and standards

Dat, Pham Tien; Kanno, Atsushi; Yamamoto, Naokatsu; Kawanishi, Tetsuya

Proceedings of the 2015 ITU Kaleidoscope: Trust in the Information Society, K-2015 - Academic Conference2016年01月-2016年01月 

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概要:© 2015 International Telecommunication Union.In addition to new radio technologies, end-to-end transport networks will play a vital role in future 5G (and beyond) networks. In particular, access transport networks connecting radio access with core networks are of critical importance. They should be able to support massive connectivity, super high data rates, and real time services in a ubiquitous environment. To attain these targets, transport networks should be constructed on the basis of a variety of technologies and methods, depending on application scenarios, geographical areas, and deployment models. In this paper, we present several technologies, including analog radioover-fiber transmission, intermediate-frequency-over-fiber technology, radio-on-radio transmission, and the convergence of fiber and millimeter-wave systems, that can facilitate building such effective transport networks in many use cases. For each technology, we present the system concept, possible application cases, and some demonstration results. We also discuss potential standardization and development directions so that the proposed technologies can be widely used.

300-GHz FM-CW radar system by optical frequency comb generation

Kanno, Atsushi; Sekine, Norihiko; Uzawa, Yoshinori; Hosako, Iwao; Kawanishi, Tetsuya; Kawanishi, Tetsuya

European Microwave Week 2015: "Freedom Through Microwaves", EuMW 2015 - Conference Proceedings; 2015 45th European Microwave Conference Proceedings, EuMCp.558 - 5612015年12月-2015年12月 

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概要:© 2015 EuMA.In this paper, we demonstrate a 300-GHz FM-CW radar using optical modulation technology. An optical frequency comb based on the optical modulation is utilized as a broadband frequency multiplier with a factor of 12. At a central frequency of 300 GHz, we generate a 12-GHz-bandwidth FM-CW signal with a pulse duration of 10 μs, realizing a precise ranging with a resolution of several centimeters. We show that the optical frequency comb generator is capable of generating larger bandwidth FM-CW signals.

Optical frequency-interleaving full-duplex transmission of 96-GHz-band frequency-modulated continuous-wave downlink signal and 10-Gb/s on-off-keying uplink signal

Kuri, Toshiaki; Kanno, Atsushi; Kawanishi, Tetsuya; Kawanishi, Tetsuya

2015 IEEE Photonics Conference, IPC 2015p.148 - 1492015年11月-2015年11月 

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概要:© 2015 IEEE.An optical frequency-interleaving full-duplex transmission of 96-GHz-band frequency-modulated continuous-wave downlink signal and 10-Gb/s on-off-keying uplink signals is investigated. The proposed full-duplexing transmission with a flexible wavelength channel selector over 10-km fiber-optic link is experimentally demonstrated.

Analog signal transmission by FPGA-based pseudo-delta-sigma modulator

Kanno, Atsushi; Kawanishi, Tetsuya; Kawanishi, Tetsuya

2015 IEEE Photonics Conference, IPC 2015p.136 - 1372015年11月-2015年11月 

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概要:© 2015 IEEE.We present a pseudo-delta-sigma modulator and demonstrate transmission using an advanced modulation. This digitally implemented transmitter helps in reducing the complexity at the receiver and realizing waveform transport over a digital optical network.

Metamaterial antenna integrated to LiNbO3 optical modulator for millimeter-wave-photonic links

Wijayanto, Y. N.; Wijayanto, Y. N.; Kanno, A.; Fathnan, A. A.; Daud, P.; Kawanishi, T.; Kawanishi, T.; Mahmudin, D.; Yamamoto, N.

2015 International Symposium on Antennas and Propagation, ISAP 20152016年04月-2016年04月 

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概要:© 2015 The Institute of Electronics, Information and Comm.We report current research progress on a metamaterial antenna integrated to an optical modulator for millimeter-wave-photonic links. The metamaterial antenna is composed by an array of electric-LC resonators on a LiNbO3 optical crystal. Large millimeter-wave electric field is induced across the capacitive gaps of the resonators due to free-space millimeter-wave irradiation. Optical modulation through Pockels effects can be obtained when light propagates along the capacitive gaps. The integrated device is operated effectively by considering interaction between millimeter-wave and lightwave electric fields along the capacitive gaps. Basic operations of the integrated device for 90GHz millimeter-wave bands are reported and discussed. Optical sidebands with carrier-to-sideband ratio of about ™60dB by millimeter-wave irradiation power of ∼20mW can be experimentally measured using optical spectrum analyzer.

300-GHz versatile transceiver front-end for both communication and imaging

Kanno, A.; Sekine, N.; Uzawa, Y.; Hosako, I.; Kawanishi, T.; Kawanishi, T.

IRMMW-THz 2015 - 40th International Conference on Infrared, Millimeter, and Terahertz Waves2015年11月-2015年11月 

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概要:© 2015 IEEE.Envelope-detector-based transceiver configurations are useful for both digital signal transmission and radar systems in the terahertz band. A dual-purpose transceiver is demonstrated using a 1-Gb/s on-off keying signal and 12.5-GHz-bandwidth frequency-modulated continuous-wave radar.

High conversion gain, low power consumption W-band photoreceiver integrated with UTC-PD and InP-PHEMT amplifier

Umezawa, T.; Akahane, K.; Kanno, A.; Yamamoto, N.; Kashima, K.; Kawanishi, T.; Kawanishi, T.

2015 International Topical Meeting on Microwave Photonics, MWP 2015 - Conference Proceedings2015年12月-2015年12月 

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概要:© 2015 IEEE.In this study, we successfully fabricated a W-band high-power photoreceiver with high output power and low power consumption. This W-band photoreceiver was integrated with a bias-free uni-travelling carrier photodetector (UTC-PD) and an InP high electron mobility transistor (PHEMT) amplifier for the first time. An ultrabroad 3 dB bandwidth beyond 110 GHz in an UTC-PD and maximum oscillation frequency of 320 GHz in a PHEMT low-noise amplifier were used for this hybrid integration. At 109 GHz, a high radio frequency output power of +10 dBm, high transimpedance gain of 828 □, and low power consumption of 67 mW was achieved in an optical-electrical converting process.

Fiber-remoted 20-Gbaud QPSK transmission at 300 GHz

Kanno, Atsushi; Sekine, Norihiko; Hosako, Iwao; Kawanishi, Tetsuya; Kawanishi, Tetsuya; Yoshida, Yuki; Kitayama, Ken Ichi

2015 International Topical Meeting on Microwave Photonics, MWP 2015 - Conference Proceedings2015年12月-2015年12月 

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概要:© 2015 IEEE.300-GHz multilevel signal transmission over optical fibers and air is demonstrated using advanced optical communication technology including optical frequency comb generation. Local oscillator signal transport over optical fibers to optical-terahertz converters removes the need for setting any terahertz-capable oscillators in the converters. This fiber-remoted configuration with seamless conversion between the optical and terahertz signals is compatible with high-speed terahertz backhaul and fronthaul links.

Suppression of optical spectrum fluctuations by stabilizing fiber loop length in optical comb generator using an optical SSB modulator

Onishi, Yoshiki; Nagatani, Norimasa; Toda, Hiroyuki; Kawanishi, Tetsuya

2015 International Topical Meeting on Microwave Photonics, MWP 2015 - Conference Proceedings2015年12月-2015年12月 

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概要:© 2015 IEEE.In this paper, we investigate the optical power fluctuation of the output in optical comb generator using an optical single sideband (SSB) modulator with a fiber loop. This fluctuation is caused by undesired sidebands of the SSB modulator. We show that the fluctuation can be suppressed by stabilizing the fiber loop length. In experiment, the averaged peak-to-peak power fluctuation of 23 comb outputs was suppressed from 0.86 dB to 0.13 dB.

High-speed optical and millimeter-wave wireless link for disaster recovery

Kitayama, Ken Ichi; Yoshida, Yuki; Yamaguchi, Yuya; Nakajima, Hirochika; Nishimura, Kosuke; Bekkali, Abdelmoula; Oishi, Masayuki; Kamiya, Naoyasu; Tanaka, Keiji; Iwai, Hidenori; Ota, Kazuya; Sato, Norihiko; Oikawa, Yoichi; Joshin, Kazukiyo; Shibagaki, Nobuhiko; Higuma, Kaoru; Oikawa, Satoshi; Ichikawa, Junichiro; Kanno, Atsushi; Kawanishi, Tetsuya

2015 IEEE Globecom Workshops, GC Wkshps 2015 - Proceedings2016年02月-2016年02月 

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概要:© 2015 IEEE.A government-funded R and D program aiming at a resilient optical and millimeter-wave wireless link for a novel span protection scheme in a disaster recovery is presented. We also describe the key enabling technologies of both optical and wireless sub- systems and devices, including MIMO radio-over- fiber system, optical two-tone generation, and the transceiver and power amplifier in W-band.

Bias-free high-baud-rate UTC-PD for high-density implementations in parallel photonics

Umezawa, T.; Matsumoto, A.; Akahane, K.; Kanno, A.; Yamamoto, N.; Kawanishi, T.; Kawanishi, T.

Asia Communications and Photonics Conference, ACPC 20152015年12月-2015年12月 

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概要:We discussed crosstalk issues on parallel photonics assuming high-density integration. RF crosstalk has become a more serious problem than optical crosstalk, and it is affected by the operating frequency (baud rate). A bias free UTC-PD was designed and fabricated. © 2015 OSA.

Advanced photonic ICT devices and their system applications using quantum-dot technology

Yamamoto, Naokatsu; Akahane, Kouichi; Umezawa, Toshimasa; Matsumoto, Atsushi; Kanno, Atsushi; Kawanishi, Tetsuya; Kawanishi, Tetsuya; Kita, Tomohiro; Yamada, Hirohito

Asia Communications and Photonics Conference, ACPC 20152015年12月-2015年12月 

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概要:Quantum-dot nanotechnology is attractive for use in advanced photonic devices that will augment the available optical-frequency resources and will increase the number of wavelength channels usable by wired and wireless networks in short/middle-range communication systems. © 2015 OSA.

Free-space millimeter-wave electro-optic modulators using quasi-phase-matching gap-embedded-patch-antennas on low dielectric constant substrate

Wijayanto, Yusuf Nur; Wijayanto, Yusuf Nur; Kanno, Atsushi; Murata, Hiroshi; Kawanishi, Tetsuya; Kawanishi, Tetsuya; Yamamoto, Naokatsu; Okamura, Yasuyuki

Springer Proceedings in Physics181p.83 - 1032016年01月-2016年01月 

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ISSN:09308989

概要:© Springer International Publishing Switzerland 2016.Conversion devices between free-space microwave/ millimeter-wave and lightwave signals are required in Fiber-Wireless (Fi-Wi) links. In this paper, we propose a free-space millimeter-wave Electro-Optic (EO) modulator using Quasi-Phase-Matching (QPM) gap-embedded-patch-antennas on a low dielectric constant substrate. Free-space millimeter-wave signals can be received and converted directly to lightwave signals using the proposed device. It can be operated passively with no external power supply and operated with extremely low millimeter-wave losses. The QPM array structure can be adopted for improving modulation efficiency by considering the transit-time effects. The proposed device is easy connected to optical fiber, therefore Fi-Wi can be realized using the proposed device. Basic structure, analysis, and experimental results of the proposed device are discussed and reported for 40 GHz operational millimeter-wave bands.

On the channel capacity of polarization-multiplexed coherent radio-over-fiber transmissions at millimeter-wave bands

Yoshida, Y.; Takami, Y.; Inudo, S.; Kitayama, K.; Kanno, A.; Yamamoto, N.; Kawanishi, T.

2016 IEEE International Conference on Communications, ICC 20162016年07月-2016年07月 

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概要:© 2016 IEEE.A closed-form capacity expression for polarization-multiplexed coherent MIMO radio-over-fiber (RoF) links at millimeter-wave bands is derived and the impact of the fiber's polarization rotation and the wireless antenna misalignment on the MIMO channel capacity is revealed. The analytical results are validated via an indoor W-band (75-110 GHz) 10-Gbaud MIMO-RoF transmission experiment.

High-efficiency W-band hybrid integrated photoreceiver module using UTC-PD and pHEMT amplifier

Umezawa, T.; Katshima, K.; Kanno, A.; Akahane, K.; Matsumoto, A.; Yamamoto, N.; Kawanishi, T.; Kawanishi, T.

Proceedings of SPIE - The International Society for Optical Engineering97472016年01月-2016年01月 

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ISSN:0277786X

概要:© 2016 SPIE.A 100-GHz narrowband photoreceiver module integrated with a zero-bias operational uni-traveling-carrier photodiode (UTC-PD) and a GaAs-based pseudomorphic high-electron-mobility transistor (pHEMT) amplifier was fabricated and characterized. Both devices exhibited flat frequency response and outstanding overall performance. The UTC-PD showed a 3-dB bandwidth beyond 110 GHz while the pHEMT amplifier featured low power consumption and a gain of 24 dB over the 85-100 GHz range. A butterfly metal package equipped with a 1.0 mm (W) coaxial connector and a microstrip-coplanar waveguide conversion substrate was designed for low insertion loss and low return loss. The fabricated photoreceiver module demonstrated high conversion gain, a maximum output power of +9.5 dBm at 96 GHz, and DC-power consumption of 0.21 W.

Transmission of multiband wireless signals over a seamless IM/DD fiber-MMW system

Van, Nguyen Toan; Dat, Pham Tien; Kanno, Atsushi; Yamamoto, Naokatsu; Bao, Vo Nguyen Quoc; Kawanishi, Tetsuya; Kawanishi, Tetsuya

IEICE Electronics Express13(15)2016年01月-2016年01月 

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ISSN:13492543

概要:© IEICE 2016.This paper proposes a high-speed multiband filtered-orthogonal frequency division multiplexing (F-OFDM) signal transmission over a seamless fiber-millimeter-wave (MMW) system at 92.5 GHz. The system employs a frequency and phase stabilized optical MMW signal generation at the transmitter and a simple direct detection at the receiver. We confirm a successful transmission of multiband F-OFDM signal over a seamless 20-km single mode fiber (SMF) and 1-m 92.5-GHz wireless system. Compared to the single-band and multiband OFDM signal transmission, the proposed system can provide a much better performance, particularly at the edges of each band.

Frequency chirp modulation by electro-optic modulator integrated with microwave rat-race circuit and measurement of chirp parameter by using optical fiber dispersion

Nakamura, Ryota; Yamamoto, Katsuyuki; Kawai, Tadashi; Enokihara, Akira; Yamamoto, Naokatsu; Kawanishi, Tetsuya; Kawanishi, Tetsuya

IEEE MTT-S International Microwave Symposium Digest2016-August2016年08月-2016年08月 

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ISSN:0149645X

概要:© 2016 IEEE.The rat-race (RR) circuit, which operates as a 180-degree hybrid, with an asymmetric power split ratio was integrated with the dual electrode type electro-optic modulator on the same substrate. Thereby, frequency chirp modulation with a compact configuration was realized. The RR circuit was designed with 4.5 1 power split ratio on a z-cut LiNbO3 substrate. The operation of the modulator was confirmed by observing the output light spectra. Moreover, the chirp parameter was directly measured by using the chromic dispersion of the optical fiber, where the power penalty of detected modulation signals transmitted through optical fiber was observed as a function of the fiber distance. The chirp parameter of the modulated light at 10 GHz was confirmed to be 0.47 by the measurement.

Radio-over-fibre based high-speed millimetre-wave backhaul system for high-speed trains

Kawanishi, Tetsuya; Kawanishi, Tetsuya; Kanno, Atsushi; Dat, Pham Tien; Yamamoto, Naokatsu

International Conference on Transparent Optical Networks2016-August2016年08月-2016年08月 

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概要:© 2016 IEEE.This paper reviews train communication networks (TCNs) based on radio-over-fibre (RoF) technology. TCNs connect base stations (BSs) in trains to world wide networks through trackside links consisting of optical fibres and many radio access units (RAUs). Waveform for radio communications can be effectively delivered to each RAU by RoF. The TCN can be controlled by train location information to reduce overhead due to hand-over in mobile communication systems.

High-capacity and high-spectral-efficiency seamless fiber-wireless system for high-speed trains

Dat, Pham Tien; Kanno, Atsushi; Yamamoto, Naokatsu; Kawanishi, Tetsuya; Kawanishi, Tetsuya

2016 Optical Fiber Communications Conference and Exhibition, OFC 20162016年08月-2016年08月 

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概要:© 2016 OSA.We propose a dual-hop network to high-speed trains by using a seamless fiber-millimeter-wave system for backhaul transmission and a high-speed in-train network. Transmission of a 64-QAM OFDM signal over the cascaded system is successfully confirmed.

Mitigation of modal crosstalk-induced power fading in mode division multiplexed W-band RoF links

Diamantopoulos, N. P.; Takami, Y.; Yoshida, Y.; Maruta, A.; Kanno, A.; Yamamoto, N.; Kawanishi, T.; Kawanishi, T.; Maruyama, R.; Kuwaki, N.; Matsuo, S.; Kitayama, K.

2016 Optical Fiber Communications Conference and Exhibition, OFC 20162016年08月-2016年08月 

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概要:© 2016 OSA.To avoid the modal crosstalk-induced power fading, a mode assignment technique has been proposed and experimentally demonstrated for mode division multiplexed W-band radio-over-fiber links.

All-spectrum fiber-wireless transmission for 5G backhaul and fronthaul links

Kanno, Atsushi; Dat, Pham Tien; Yamamoto, Naokatsu; Hosako, Iwao; Yoshida, Yuki; Kitayama, Ken Ichi; Kawanishi, Tetsuya; Kawanishi, Tetsuya

2016 Optical Fiber Communications Conference and Exhibition, OFC 20162016年08月-2016年08月 

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概要:© 2016 OSA.This paper presents the simultaneous transmission of millimeter-wave and terahertz-wave radio signals over an optical fiber and air by a single optical frequency comb source with several types of receiver configurations.

31-GHz single-carrier, 44.6-Gbps photonic wireless transmission using a wide-bandwidth high power photodetector and a pre-distortion technique

Umezawa, T.; Jitsuno, K.; Shibagaki, N.; Kanno, A.; Akahane, K.; Mstsumoto, A.; Yamamoto, N.; Kawanishi, T.; Kawanishi, T.

2016 Optical Fiber Communications Conference and Exhibition, OFC 20162016年08月-2016年08月 

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概要:© 2016 OSA.Single-carrier photonic wireless transmission at 31 GHz and 8.0 Gbaud with 64QAM is successfully achieved with error-free operation. A newly developed wide bandwidth high power photodetector and a pre-equalizing subsystem are presented.

Low-latency fiber-millimeter-wave system for future mobile fronthauling

Tien Dat, Pham; Kanno, Atsushi; Yamamoto, Naokatsu; Kawanishi, Tetsuya

Proceedings of SPIE - The International Society for Optical Engineering97722016年01月-2016年01月 

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ISSN:0277786X

概要:© 2016 SPIE.A seamless combination of fiber and millimeter-wave (MMW) systems can be very attractive for future heterogeneous mobile networks such as 5G because of its flexibility and high bandwidth. Analog mobile signal transmission over seamless fiber-MMW systems is very promising to reduce the latency and the required band-width, and to simplify the systems. However, stable and high-performance seamless systems are indispensable to conserve the quality of the analog signal transmission. In this paper, we present several technologies to develop such seamless fiber-MMW systems. In the downlink direction, a high-performance system can be realized using a high-quality optical MMW signal generator and a self-homodyne MMW signal detector. In the uplink direction, a cascade of radio-on-radio and radio-over-fiber systems using a burst-mode optical amplifier can support bursty radio signal transmission. A full-duplex transmission with negligible interference effects can be realized using frequency multiplexing in the radio link and wavelength-division multiplexing in the optical link. A high-spectral efficiency MMW-over-fiber system using an intermediate frequency-over-fiber system and a high-quality remote delivery of a local oscillator signal is highly desirable to reduce the costs.

Terahertz-wave signal synthesizer for fiber-wireless seamless access network

Kanno, Atsushi; Dat, Pham Tien; Sekine, Norihiko; Kasamatsu, Akifumi; Yamamoto, Naokatsu; Kawanishi, Tetsuya

2016 IEEE 6th International Conference on Communications and Electronics, IEEE ICCE 2016p.403 - 4072016年09月-2016年09月 

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概要:© 2016 IEEE.A photonic terahertz synthesizer is configured and demonstrated by 100-GH, 300-GHz and 600-GHz signal generation. An optical frequency shifter in an amplified optical fiber loop technique configures an optical frequency comb generator with a resultant optical bandwidth up to 2 THz. An observed phase noise characteristic by the photonic synthesizer is considerable for application to the complex modulation formats even in the terahertz bands.

Seamless access networks using radio-over-fiber technology for high-speed trains

Kawanishi, Tetsuya; Kanno, Atsushi; Dat, Pham Tien; Yamamoto, Naokatsu

2016 IEEE 6th International Conference on Communications and Electronics, IEEE ICCE 2016p.381 - 3842016年09月-2016年09月 

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概要:© 2016 IEEE.This paper reviews seamless networks based on radio-over-fiber (RoF) technology. We focus on train communication networks (TCNs) consisting of optical networks and many radio access units (Raus). Waveform for radio communications can be effectively delivered to each Rau by RoF. The TCN can be controlled by train location information to reduce overhead due to hand-over in mobile communication systems.

High conversion Gain 30-110 GHz photoreceivers for high data-rate advanced photonic wireless communications

Umezawa, T.; Jitsuno, K.; Kanno, A.; Yamamoto, N.; Kawanishi, T.

2016 IEEE 6th International Conference on Communications and Electronics, IEEE ICCE 2016p.389 - 3922016年09月-2016年09月 

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概要:© 2016 IEEE.We report a 30-110 GHz, high conversion gain, and high output photodetector consisting of a hybrid integration of a high-speed photodetector and an RF amplifier with an additional gain emphasis circuit. High data-rate photonic wireless communication over 44 Gbps was demonstrated with a pre-distortion technique. The minimum optical input power level for an error free operation was also discussed.

5G TRANSPORT NETWORKS: THE NEED FOR NEW TECHNOLOGIES AND STANDARDS

Dat, Pham Tien;Kanno, Atsushi;Yamamoto, Naokatsu;Kawanishi, Tetsuya

IEEE COMMUNICATIONS MAGAZINE54(9)p.18 - +2016年-2016年

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ISSN:0163-6804

Demonstration of ultraprecision ductile-mode cutting for lithium niobate microring waveguides

Takigawa, Ryo;Higurashi, Eiji;Kawanishi, Tetsuya;Asano, Tanemasa

JAPANESE JOURNAL OF APPLIED PHYSICS55(11)2016年-2016年

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ISSN:0021-4922

Seamless Fiber-Wireless Bridge in the Millimeter- and Terahertz-Wave Bands

Kanno, Atsushi;Pham Tien Dat;Sekine, Norihiko;Hosako, Iwao;Yamamoto, Naokatsu;Yoshida, Yuki;Kitayama, Ken-Ichi;Kawanishi, Tetsuya

JOURNAL OF LIGHTWAVE TECHNOLOGY34(20)p.4794 - 48012016年-2016年

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ISSN:0733-8724

100-GHz Fiber-Fed Optical-to-Radio Converter for Radio- and Power-Over-Fiber Transmission

Umezawa, Toshimasa;Kashima, Kenichi;Kanno, Atsushi;Matsumoto, Atsushi;Akahane, Kouichi;Yamamoto, Naokatsu;Kawanishi, Tetsuya

IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS23(3)2017年-2017年

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ISSN:1077-260X

Electro-optic modulator using millimeter-wave gap-embedded patch antenna with stacked structure

Aya, Hironori; Wijayanto, Yusuf Nur; Kanno, Atsushi; Kawanishi, Tetsuya; Kawanishi, Tetsuya; Murata, Hiroshi; Okamura, Yasuyuki

2016 21st OptoElectronics and Communications Conference, OECC 2016 - Held Jointly with 2016 International Conference on Photonics in Switching, PS 20162016年10月-2016年10月 

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概要:© 2016 IEICE.We propose new electro-optic modulators using gap-embedded patch antennas with stacked structure. Utilizing stacked structure, the antenna gain, electric field for modulation, and interaction length increase, then modulation efficiency increases 3.65 dB at 60 GHz.

Mode-division multiplexing LiNbO3 modulator using directional coupler

Kodama, Yutaro; Yamaguchi, Yuya; Kanno, Atsushi; Kawanishi, Tetsuya; Kawanishi, Tetsuya; Izutsu, Masayuki; Izutsu, Masayuki; Nakajima, Hirochika

2016 21st OptoElectronics and Communications Conference, OECC 2016 - Held Jointly with 2016 International Conference on Photonics in Switching, PS 20162016年10月-2016年10月 

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概要:© 2016 IEICE.We designed and fabricated a LiNbO3 integrated optical modulator for mode-division multiplexing, where optical signals in two modes can be independently controlled and combined together. Mode crosstalk was smaller than -20dB in C-band.

Measurement of vectorial response of IQ modulator using optical interference

Yamaguchi, Yuya; Seki, Kazuki; Takahashi, Naoki; Kanno, Atsushi; Kawanishi, Tetsuya; Kawanishi, Tetsuya; Izutsu, Masayuki; Izutsu, Masayuki; Nakajima, Hirochika

2016 21st OptoElectronics and Communications Conference, OECC 2016 - Held Jointly with 2016 International Conference on Photonics in Switching, PS 20162016年10月-2016年10月 

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概要:© 2016 IEICE.We propose a new measurement method of modulator response in phasor domain for Mach-Zehnder modulators embedded in IQ modulator using simple equipments. The modulation curve with extinction ratio of 14.7 and 22 dB were measured.

11-Gbps 16-QAM OFDM radio over fiber demonstration using 100 GHz high-efficiency photoreceiver based on photonic power supply

Umezawa, T.; Kashima, K.; Kanno, A.; Akahane, K.; Matsumoto, A.; Yamamoto, N.; Kawanishi, T.; Kawanishi, T.

2016 21st OptoElectronics and Communications Conference, OECC 2016 - Held Jointly with 2016 International Conference on Photonics in Switching, PS 20162016年10月-2016年10月 

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概要:© 2016 IEICE.A 100 GHz photoreceiver was designed, fabricated, and integrated with a pHEMT amplifier, based on a photonic power supply. In this paper, a high data rate photonic wireless communication over 11 Gbps is demonstrated.

Efficient mobile fronthaul for simultaneous transmission of 4G and future mobile signals

Dat, Pham Tien; Kanno, Atsushi; Yamamoto, Naokatsu; Kawanishi, Tetsuya; Kawanishi, Tetsuya

2016 21st OptoElectronics and Communications Conference, OECC 2016 - Held Jointly with 2016 International Conference on Photonics in Switching, PS 20162016年10月-2016年10月 

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概要:© 2016 IEICE.We present an efficient mobile fronthaul system for co-transmission of radio signals in the microwave and millimeter-wave bands. We successfully transmit a WLAN and an LTE-A signal at 2.6 GHz and 33.6 GHz, respectively, over the system.

OFDM millimeter-wave radar experiment combined with radio over fiber technology

Umezawa, T.; Jitsuno, K.; Kanno, A.; Akahane, K.; Yamamoto, N.; Kawanishi, T.

International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz2016-November2016年11月-2016年11月 

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ISSN:21622027

概要:© 2016 IEEE.We have demonstrated an orthogonal frequency division multiplexing (OFDM) radar experiment combined with millimeter-wave radio over fiber (RoF). In result, high flame rate and high space resolution of 30 cm in 5 m distance (theoretical space resolution of 1.52 cm) was successfully achieved.

Change of frequency separation for two-mode quantum dot lasers by using a birefringent etalon filter

Akahane, Kouichi; Inui, Masaki; Umezawa, Toshimasa; Kanno, Atsushi; Yamamoto, Naokatsu; Kawanishi, Tetsuya; Sotobayashi, Hideyuki

International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz2016-November2016年11月-2016年11月 

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ISSN:21622027

概要:© 2016 IEEE.We have developed a stable two-mode laser by using a quantum dot optical gain chip in an external cavity. In this study, we demonstrate continuous change of frequency separation of a two-mode laser by using a birefringent etalon filter. Since the polarization of the quantum dot optical gain chip is TE-dominant, the frequency separation of the two-mode laser is controlled by rotating the birefringent etalon filter. We can change the frequency separation from 84 to 93 GHz by using this method.

Millimeter-wave radio-over-fiber system for high-speed railway communication

Kanno, A.; Dat, P. T.; Yamamoto, N.; Kawanishi, T.

2016 Progress In Electromagnetics Research Symposium, PIERS 2016 - Proceedingsp.3911 - 39152016年11月-2016年11月 

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概要:© 2016 IEEE.We propose an architecture of the radio-over-fiber systems for train communication networks. Prediction-based dynamic optical routing can track the train cars by train location information. High spectral-efficient millimeter-wave signal modulation and demodulation are also discussed with the modulation format and its configuration of the frequency conversions in the paper.

High-conversion-gain 100-GHz photoreceiver integrated with UTC-PD and PHEMT amplifier for 92-GHz carrier, 10.7-Gbps photonic wireless communication

Umezawa, T.; Kashima, K.; Kanno, A.; Dat, P. T.; Akahane, K.; Matsumoto, A.; Yamamoto, N.; Kawanishi, T.; Kawanishi, T.

EuMIC 2016 - 11th European Microwave Integrated Circuits Conferencep.468 - 4712016年12月-2016年12月 

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概要:© 2016 European Microwave Association.We successfully designed and fabricated a high-conversion-gain 100-GHz photoreceiver integrated with a UTC-PD and a PHEMT amplifier for 92-GHz carrier photonic wireless communication. Then, in a demonstration of 92-GHz carrier, OFDM, 16-QAM photonic wireless communication, we confirmed that high data rate of 11.03-Gbps (bit error rate of 1×10-3) could be achieved at a low optical input power, without post amplifiers for the photoreceiver. The designs and the results are discussed.

Polarization dependence of avalanche multiplication factor in 1.5 μm quantum dot waveguide photodetector

Umezawa, T.; Akahane, K.; Matsumoto, A.; Kanno, A.; Yamamoto, N.; Kawanishi, T.; Kawanishi, T.

2016 Conference on Lasers and Electro-Optics, CLEO 20162016年12月-2016年12月 

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概要:© 2016 OSA.We fabricated 1.5 μm quantum dot waveguide photodetector, and characterized the electrical and optical properties. It was found that the avalanche photocurrent strongly depends on TE/TM polarization.

100 GHz fiber-fed optical-to-radio converter

Umezawa, T.; Kashima, K.; Akahane, K.; Kanno, A.; Yamamoto, N.; Kawanishi, T.; Kawanishi, T.

2016 Conference on Lasers and Electro-Optics, CLEO 20162016年12月-2016年12月 

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概要:© 2016 OSA.We demonstrate 100-GHz optical-to-radio converter without electric power supplies by combination of a newly developed bias-free-operational UTC-PD and an integrated bias-tee for effective regeneration of the supplied power to a 100-GHz amplifier.

Performance of 90GHz electro-optic modulator with patch-antennas in high-power wireless irradiation

Wijayanto, Yusuf Nur; Wijayanto, Yusuf Nur; Kanno, Atsushi; Kawanishi, Tetsuya; Kawanishi, Tetsuya; Murata, Hiroshi; Yamamoto, Naokatsu; Okamura, Yasuyuki

2016 Conference on Lasers and Electro-Optics, CLEO 20162016年12月-2016年12月 

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概要:© 2016 OSA.We report a recent progress for performance of 90GHz electro-optic modulator with patch-antennas in high-power wireless radio irradiation. Optical sidebands to carrier ratio of -40dB can be achieved by wireless radio irradiation power of 33dBm.

Investigation on phase-sensitive fiber nonlinearity cancellation in conjugated-paired radio-on-fiber system

Sakamoto, Takahide; Lu, Guo Wei; Lu, Guo Wei; Kawanishi, Tetsuya; Kawanishi, Tetsuya

2016 Conference on Lasers and Electro-Optics, CLEO 20162016年12月-2016年12月 

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概要:© 2016 OSA.We clarify that fiber nonlinearity cancellation in the conjugated-paired radio-on-fiber system is a phase sensitive process. The best nonlinearity tolerance is achieved if the dual sidebands are constructively superposed during photonic down conversion.

92GHz 64QAM signal generation by optical frequency doubler

Kanada, Naoki; Yonemoto, Naruto; Kawanishi, Tetsuya

2016 IEEE International Topical Meeting on Microwave Photonics, MWP 2016p.145 - 1482016年12月-2016年12月 

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概要:© 2016 IEEE.New communication system for high-speed train passengers is required to provide broadband services in the train. Radio over fiber in millimeter wave band is considered to provide a high throughput of the system. As a proof of concept, we generate 92 GHz 200 M symbol/sec 64QAM signals by optical frequency doubler. EVM of the signal is 7.14%. The result shows 1.2Gbps transmission is available in MMW band by radio over fiber.

Experimental demonstration of fiber-nonlinearity-Torelant conjugated-paired radio-on-fiber system employing asymmetric photonic heterodyne down-converter

Sakamoto, Takahide; Lu, Guo Wei; Lu, Guo Wei; Kawanishi, Tetsuya; Kawanishi, Tetsuya

2016 IEEE International Topical Meeting on Microwave Photonics, MWP 2016p.51 - 542016年12月-2016年12月 

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概要:© 2016 IEEE.We experimentally demonstrate fiber-nonlinearity-Tolerant conjugated-paired radio-on-fiber (C-RoF) system for the first time. A C-RoF signal is simply generated by dual-sideband modulation and fiber nonlinearity is cancelled through asymmetric photonic heterodyne down-conversion. A QPSK-C-RoF signal is transferred over 20-km SMF fiber.

Simultaneous transmission of 4G LTE-A and wideband MMW OFDM signals over fiber links

Dat, Pham Tien; Kanno, Atsushi; Yamamoto, Naokatsu; Kawanishi, Tetsuya; Kawanishi, Tetsuya

2016 IEEE International Topical Meeting on Microwave Photonics, MWP 2016p.87 - 902016年12月-2016年12月 

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概要:© 2016 IEEE.We present efficient mobile fronthaul systems for simultaneous transmission of radio signals in the microwave and millimeter-wave bands over fiber links. We compare the performance for signal transmission over intermediate frequency over fiber systems using an electrical and optical up-conversion to the MMW band at remote sites. We experimentally confirm the successful transmission of an LTE-A signal at 2.6 GHz and a wideband OFDM signal at 35.4 GHz over the systems.

Wide frequency range optical synthesizer with high-frequency resolution

Kiuchi, Hitoshi; Kawanishi, Tetsuya; Kanno, Atsushi

IEEE Photonics Technology Letters29(1)p.78 - 812017年01月-2017年01月 

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ISSN:10411135

概要:© 1989-2012 IEEE.The generation of high-frequency signals including those in the terahertz region has become indispensable in state-of-the-art communication systems. A synthesizer as a measurement device generates signals of desired frequencies with high-frequency resolution. Electric signals (microwaves or millimeter waves) can be generated by a photomixer performing optical-electrical energy conversion based on the phase difference between two coherent optical signals. Recently, the frequency bandwidth for photomixers has reached the terahertz region and photomixers are now more readily available. The main purpose of this letter is to provide an optical synthesizer with a high-frequency resolution (better than 1 Hz) and with seamless frequency coverage from the microwave to the terahertz-wave regions using one apparatus. The system is designed in such a way that the mean of the resolution frequency includes the frequency instability of the generated signal.

High characteristic temperature for ridge-waveguide laser with a highly stacked InAs quantum dot structure

Akahane, Kouichi; Matsumoto, Atsushi; Umezawa, Toshimasa; Yamamoto, Naokatsu; Kawanishi, Tetsuya

Conference Digest - IEEE International Semiconductor Laser Conference2016年12月-2016年12月 

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ISSN:08999406

概要:© 2016 IEICE-ES.A ridge-waveguide laser with highly stacked InAs quantum dot structure based on strain compensation technique was fabricated. The threshold current of this laser was decreased to approximately 75 mA without coating the facet mirror. A high characteristic temperature of over 100 K was obtained using this laser.

High speed photoreceiver over 100 GHz and its application

Umezawa, T.; Kashima, K.; Akahane, K.; Matsumoto, A.; Kanno, A.; Yamamoto, N.; Kawanishi, T.; Kawanishi, T.

2016 IEEE Photonics Conference, IPC 2016p.562 - 5632017年01月-2017年01月 

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概要:© 2016 IEEE. In wireless communications, the data traffic increases rapidly every year, as well as in fixed optical fiber communications, where the trend for data traffic is not saturated yet. In the next generation of advanced wireless communication services, a high data rate, high capacity, low latency, and low cost are desired. The large radio cover area for present macro-cell should be divided into plenty of small-cells in order to mitigate heavy data traffic in the one macro-cell [1]. Here, radio over fiber (RoF) is a promising technology for access networks such as mobile back-haul and front-haul in wireless communication. High data rate transmission through optical fibers should be introduced near end-user points and be converted to radio signals from simple antennas in small-cells. Here, a high speed photoreceiver is one of key components in RoF communications. On the other hand, power over fiber (PoF) technology, which provides electric power supply through optical fibers, is a compatible technology with a good affinity to RoF technology. The 90 to 110 GHz band is a very attractive frequency band, which involves not only low atmospheric attenuation [2] but also a wider bandwidth compared to that in the microwave region.

90 Gb/s hybrid integrated photoreceiver module with high speed 1.5 μm-band QD-SOA

Matsumoto, A.; Umezawa, T.; Akahane, K.; Kanno, A.; Yamamoto, N.; Kawanishi, T.

Conference Digest - IEEE International Semiconductor Laser Conference2016年12月-2016年12月 

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ISSN:08999406

概要:© 2016 IEICE-ES.We investigated fundamental characteristics of a hybrid integrated photoreceiver module with a 1.5 μm-band quantum dot semiconductor optical amplifier (QD-SOA) and conventional pin-photodiode (pin-PD) as a first stage. The results indicated the photoreceiver integrated with a QD-SOA and QD-PD has the potential to be operated for signals over 100 Gb/s.

Multi-layered stacked patch-antennas on electro-optic material for optical modulation

Wijayanto, Y. N.; Wijayanto, Y. N.; Kanno, A.; Kawanishi, T.; Kawanishi, T.; Murata, H.; Umezawa, T.; Yamamoto, N.; Okamura, Y.

European Microwave Week 2016: "Microwaves Everywhere", EuMW 2016 - Conference Proceedings; 46th European Microwave Conference, EuMC 2016p.945 - 9482017年01月-2017年01月 

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概要:© 2016 EuMA.Multi-layered stacked patch-antennas on an electro-optic (EO) material are proposed for optical modulation. By using multi-layered structures, larger antenna gain can be obtained to induce stronger millimeter-wave electric fields. The induced millimeter-wave electric field can be used for optical modulation through the Pockels effects of the EO crystal. Since the antenna gain is enhanced by using multi-layered stacked patch-antennas, the modulation index improvement can be obtained.

High-conversion-gain 100-GHz photoreceiver integrated with UTC-PD and PHEMT amplifier for 92-GHz carrier, 10.7-Gbps photonic wireless communication

Umezawa, T.; Kashima, K.; Kanno, A.; Dat, P. T.; Akahane, K.; Matsumoto, A.; Yamamoto, N.; Kawanishi, T.; Kawanishi, T.

European Microwave Week 2016: "Microwaves Everywhere", EuMW 2016 - Conference Proceedings; 46th European Microwave Conference, EuMC 2016p.1397 - 14002017年01月-2017年01月 

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概要:© 2016 EuMA.We successfully designed and fabricated a high-conversion-gain 100-GHz photoreceiver integrated with a UTC-PD and a PHEMT amplifier for 92-GHz carrier photonic wireless communication. Then, in a demonstration of 92-GHz carrier, OFDM, 16-QAM photonic wireless communication, we confirmed that high data rate of 11.03-Gbps (bit error rate of 1× 10-3) could be achieved at a low optical input power, without post amplifiers for the photoreceiver. The designs and the results are discussed.

Wireless millimeter-wave-lightwave signal converter using stacked patch-antennas embedded with a micrometer-gap and electro-optic crystal

Aya, Hironori; Inoue, Toshiyuki; Murata, Hiroshi; Okamura, Yasuyuki; Wijayanto, Yusuf Nur; Wijayanto, Yusuf Nur; Kanno, Atsushi; Kawanishi, Tetsuya; Kawanishi, Tetsuya

Proceeding - 2016 International Conference on Radar, Antenna, Microwave, Electronics, and Telecommunications, ICRAMET 2016p.77 - 802017年02月-2017年02月 

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概要:© 2016 IEEE. We have proposed a new electro-optic signal converter which enables us to convert wireless millimeter-wave signals to lightwave signals. This is based on a LiNbO 3 guided-wave optical modulator combined with vertically-stacked planar patch antennas embedded with a narrow (∼5 μm) gap. Utilizing the stacked structure, the antenna gain, antenna area, and electric field for optical modulation are increased, so that the signal conversion efficiency is increased by 3.65 dB at 60 GHz.

Key technologies for millimeter-wave distributed RADAR system over a radio over fiber network

Kanno, Atsushi; Umezawa, Toshimasa; Kuri, Toshiaki; Yamamoto, Naokatsu; Wijayanto, Yusuf Nur; Kawanishi, Tetsuya

Proceeding - 2016 International Conference on Radar, Antenna, Microwave, Electronics, and Telecommunications, ICRAMET 2016p.1 - 62017年02月-2017年02月 

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概要:© 2016 IEEE. We discuss key device technologies for realization of an optical-fiber-network-connected distributed radar system in the millimeter-wave band using radio over fiber techniques. The radio over fiber technique is useful for precise signal generation and distribution over the fiber network. In the scenario, each millimeter-wave radar head is not necessary to be equipped with a precision radar signal source; low cost and low energy consumption radar head will be realized. For connection to the optical network, advanced high-speed optical/electrical converters are developed for signal conversion from/to optical signals in 90-GHz band directly in a central office and each radar head. A signal-to-noise power ratio of generated 90-GHz optical signal was achieved larger than 30 dB: enough quality to use in the radar system. An optical switching technique is useful not only for routing the optical signal to the radar heads but also for filtering unnecessary optical components. These device technologies are applicable for distributed millimeter-wave radar systems.

High-responsivity 100GHz waveguide UTC photodetector

Umezawa, T.; Akahane, K.; Matsumoto, A.; Kanno, A.; Yamamoto, N.; Kawanishi, T.

Proceedings of SPIE - The International Society for Optical Engineering101282017年01月-2017年01月 

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ISSN:0277786X

概要:© 2017 COPYRIGHT SPIE.We present a double cladding, high-mesa-type waveguide UTC photodetector with an improved the responsivity. In this device structure, an InGaAs thin core layer was sandwiched by p-InP/InGaAsP and n-InP/InGaAsP cladding layers, including a UTC structure, in order to obtain a good optical coupling between the waveguide and the fiber. By comparing the resulting mode field with that obtained with a single cladding layer structure, we confirmed that the vertical mode field was enlarged. Without a spot size converter, the measured responsivity was as high as 0.6 A/W at 1550 nm, which suggests a responsivity three times higher than that of back-illuminated structures, and higher responsivity than that of previous reports. A high frequency performance (f3dB = 100 GHz) was also measured. The device structure, including the layer, doping level conditions, and optical fiber coupling results are discussed, and its performance is characterized in detail.

Coexistence and transmission of multiple radios over seamless fiber-wireless systems

Tien Dat, Pham; Kanno, Atsushi; Yamamoto, Naokatsu; Kawanishi, Tetsuya

Proceedings of SPIE - The International Society for Optical Engineering101282017年01月-2017年01月 

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ISSN:0277786X

概要:© 2017 COPYRIGHT SPIE.In this paper, we present efficient solutions for simultaneous transmission of multiple radio signals over seamless fiber wireless systems, including radio signals in legacy microwave bands and in high frequency bands. At central stations, radio signals can be mapped onto the same optical transport channel using data mapping algorithms and/or subcarrier multiplexing technique. After the fiber transmission, the received signals can be down-converted, digitized, and de-mapped to recover the originally transmitted signals. We present and compare two different methods, including a radio-over-fiber system and optical up-conversion at remote sites and an intermediate-frequency-over-fiber system and an electrical up-conversion at remote sites. We experimentally confirm the suitability of both the transmission methods, and achieve satisfactory performance for all signals, including LTE-advanced, orthogonal frequency-division multiplexing, and filtered-orthogonal frequency-division multiplexing signals. In particular, the latter method can provide a high optical spectral efficiency and low fiber dispersion effect and is suitable for ultra-dense small cell deployment in future mobile networks.

Simultaneous transmission of Multi-RATs and mobile fronthaul in the MMW bands over an IFoF System

Dat, Pham Tien; Kanno, Atsushi; Yamamoto, Naokatsu; Kawanishi, Tetsuya; Kawanishi, Tetsuya

2017 Optical Fiber Communications Conference and Exhibition, OFC 2017 - Proceedings2017年05月-2017年05月 

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概要:© 2017 Optical Society of America. We propose and demonstrate a simultaneous transmission of LTE-A, 25-GHz OFDM/FBMC radio access, and 96-GHz filtered-OFDM mobile fronthaul signals over a simple and low cost intermediate-frequency-over-fiber system. We confirm the successful transmission of all signals.

100 GHz optical-to-radio converter module and its application in radio and power over fiber transmission through multi-core fiber

Umezawa, T.; Dat, P. T.; Hase, E.; Kashima, K.; Kanno, A.; Akahane, K.; Mstsumoto, A.; Yamamoto, N.; Kawanishi, T.; Kawanishi, T.

2017 Optical Fiber Communications Conference and Exhibition, OFC 2017 - Proceedings2017年05月-2017年05月 

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概要:© 2017 Optical Society of America. We developed a 100 GHz optical-to-radio converter module integrated with a 100 GHz amplifier, which was applied in radio (12-Gbps, OFDM, 16-QAM, IF = 92-GHz) and power over fiber transmission through a multi-core fiber.

Millimeter-Wave Integrated Photoreceivers for High Data Rate Photonic Wireless Communication

Umezawa, Toshimasa; Jitsuno, Kunihisa; Dat, Pham Tien; Kashima, Kenichi; Kanno, Atsushi; Yamamoto, Naokatsu; Kawanishi, Tetsuya; Kawanishi, Tetsuya

IEEE Journal of Selected Topics in Quantum Electronics24(2)2018年03月-2018年03月 

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ISSN:07921233

概要:© 1995-2012 IEEE. We report on the use of 30 and 100 GHz integrated millimeter-wave photoreceivers in high data rate photonic wireless communication. The role of the bandwidth of a narrow-band photoreceiver in increasing the data rate of wireless single carrier transmission is discussed. An 11-GHz bandwidth photoreceiver achieved a data rate of 44.6 Gb/s using an 8 GBd, 64-QAM (quadrature amplitude modulation) signal. A wider bandwidth (19 GHz) integrated photoreceiver was designed and fabricated for use in the 100-GHz range. High-frequency response photoreceivers have the following advantages: they operate in a wide bandwidth easily, use frequency resources efficiently, and are subject to low amounts of atmospheric attenuation. In addition to the single carrier wireless transmission study, a high data rate (12 Gb/s) multicarrier radio over fiber (16-QAM in orthogonal frequency division multiplexing) transmission experiment was demonstrated in order to confirm the ability to increase the data rate with a wide operational bandwidth.

100-GHz Radio and Power over Fiber Transmission Through Multicore Fiber Using Optical-to-Radio Converter

Umezawa, Toshimasa; Dat, Pham Tien; Kashima, Kenichi; Kanno, Atsushi; Yamamoto, Naokatsu; Kawanishi, Tetsuya; Kawanishi, Tetsuya

Journal of Lightwave Technology36(2)p.617 - 6232018年01月-2018年01月 

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ISSN:07338724

概要:© 1983-2012 IEEE. We designed and fabricated a 100-GHz range integrated photoreceiver with zero-bias operational uni-traveling-carrier photodiode and pseudomorphic high electron mobility transistor amplifier, which performed the roles of photonic power generation and 100-GHz RF signal generation. Using the integrated photoreceiver, high data rate radio- and power-over-fiber transmission through multicore fiber communication was demonstrated. Subsequently, a bit error rate of 1× 10- 3 could be achieved with 12 Gb/s, orthogonal frequency division multiplexing, 16 quadrature amplitude modulation, and an intermediate frequency of 92 GHz. The crosstalk issue in radio- and power-over-fiber transmission through multicore fiber was discussed.

Optical fiber network-connected distributed mm-wave radar system

Kawanishi, Tetsuya; Kawanishi, Tetsuya; Kanno, Atsushi; Yamamoto, Naokatsu; Yonemoto, Naruto; Shibagaki, Nobuhiko; Kashima, Ken Ichi

Summer Topicals Meeting Series, SUM 2017p.197 - 1982017年08月-2017年08月 

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概要:© 2017 IEEE. This presentation reviews radar systems with many antenna units connected by optical networks, which distribute waveforms of wideband frequency modulated millimeter-wave signals, where the range resolution can be a few centimeters.

Millimeter- and terahertz-wave radio-over-fiber for 5G and beyond

Dat, Pham Tien; Kanno, Atsushi; Umezawa, Toshimasa; Yamamoto, Naokatsu; Kawanishi, Tetsuya; Kawanishi, Tetsuya

Summer Topicals Meeting Series, SUM 2017p.165 - 1662017年08月-2017年08月 

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概要:© 2017 IEEE. This paper reviews our recent research activities on seamless fiber-wireless systems for future mobile networks, including: radio-on-radio-over-fiber; signal processing-aided multiple signal transmission; high-capacity seamless system; and simultaneous power- and radio-over-fiber.

Precise Optical Modulation Using Extinction-Ratio and Chirp Tunable Single-Drive Mach-Zehnder Modulator

Yamaguchi, Yuya; Kanno, Atsushi; Kawanishi, Tetsuya; Kawanishi, Tetsuya; Izutsu, Masayuki; Nakajima, Hirochika

Journal of Lightwave Technology35(21)p.4781 - 47882017年11月-2017年11月 

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ISSN:07338724

概要:© 1983-2012 IEEE. We analyzed the complex transfer function and modulation spectrum of the Mach-Zehnder (MZ) modulator with optical power and phase change imbalances. From the calculations, we found that the characteristic operation can be obtained in three cases: high extinction ratio, zero-chirp, and straight-line trajectory in the IQ plane. However, the results also indicate that we cannot achieve an operation equivalent to that of the ideal modulator, due to the small parasitic chirp in a single-drive modulator. To control the extinction ratio and chirp parameter individually, we propose an integrated modulator with some tunable Y-branches. By using the optical-power-imbalance tunable modulators, we experimentally demonstrate the characteristic operations and obtain the modulation spectrum equivalent to the ideal MZ modulator. However, compared to the ideal amplitude modulator, MZ modulators exhibit an intrinsic nonlinearity in the sinusoidal response. Therefore, we used a third-order nonlinearity compensation method using the superposition of electrical third-order harmonics. The measured spectrum consisted of only first-order modulation sidebands, which is equivalent to the ideal double-sideband suppressed-carrier modulation.

Concept of sensor over fibres and its application to high resolution millimetre-wave radar

Kawanishi, Tetsuya; Kawanishi, Tetsuya; Kanno, Atsushi; Yamamoto, Naokatsu

International Conference on Transparent Optical Networks2017年09月-2017年09月 

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概要:© 2017 IEEE. This paper describes the concept of sensor over fibres (SoF), consisting of many sensor heads connected by fibre networks. SoF transfer waveforms from the sensor heads and performs joint signal processing to achieve high-resolution and agile imaging, while wireless sensor networks are digital networks to collect measured data at small sensors. SoF can compile information from sensor heads coherently at central signal processing units. We will also show applications of SoF technologies, such as high resolution millimetre-wave radar for airport runway surveillance.

100-GHz integrated photoreceiver using optical-to-radio converter and enhancement mode PHEMT amplifier driven by photonic power supply

Umezawa, Toshimasa; Hase, Eiichi; Kanno, Atsushi; Matsumoto, Atsushi; Akahane, Kouichi; Yamamoto, Naokatsu; Kawanishi, Tetsuya; Kawanishi, Tetsuya

IEEE MTT-S International Microwave Symposium Digestp.1865 - 18682017年10月-2017年10月 

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ISSN:0149645X

概要:© 2017 IEEE. We present a 100-GHz integrated photoreceiver using an optical-to-radio converter and an enhancement-mode PHEMT amplifier driven by all optical resources without an external electric power supply. Technology for the simultaneous generation of radio and power was developed using a zero-bias operational uni-travelling carrier (UTC) high-speed photodetector. To improve the optical-to-electrical conversion efficiency, a 110-GHz enhancement-mode InP-PHEMT amplifier was also newly developed, which operates using an internal electric power supply in an optical-to-radio converter. Using a hybrid integration based on all optical resources, a +5.5 dBm RF output at 97 GHz was successfully achieved through the optical-to-radio conversion process. Herein, the two key devices and the integrated photoreceiver are discussed.

Mode separation control of few-mode quantum dot lasers by using a multistep etalon filter

Akahane, Kouichi; Inui, Masaki; Sakamoto, Ryuji; Nakane, Shingo; Iwao, Masaru; Umezawa, Toshimasa; Matsumoto, Atsushi; Kanno, Atsushi; Yamamoto, Naokatsu; Kawanishi, Tetsuya; Sotobayashi, Hideyuki

International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz2017年10月-2017年10月 

DOIScopus

詳細

ISSN:21622027

概要:© 2017 IEEE. Semiconductor quantum dots can be used for an optical gain-chip in an external cavity to construct a stable two- or few-mode laser. In this study, we demonstrate wide-range mode separation control of a few-mode laser by using a multistep etalon filter. Since the precise control of multistep thickness in one etalon plate was achieved, the frequency separation of the few-mode laser can be changed by choosing the etalon position. We can change the frequency separation from 83 to 104 GHz by using this method.

80-GHz signal detection in high speed UTC-PD using EO sampling THz probe

Umezawa, Toshimasa; Morohashi, Isao; Ogawa, Yoh; Akahane, Kouichi; Matsumoto, Atsushi; Kanno, Atsushi; Sekine, Norohiko; Yamamoto, Naokatsu; Hosako, Iwao; Kawanishi, Tetsuya; Kawanishi, Tetsuya

International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz2017年10月-2017年10月 

DOIScopus

詳細

ISSN:21622027

概要:© 2017 IEEE. The W-band signal near the antenna surface is detected using a THz probing system, by assuming near/far electric field distribution measurement on a phased array antenna coupled to an RoF radar system. By using 10 GHz + 12.5 kHz optical sampling pulse with a ZnTe EO probing head, the 80-GHz signal generated by a UTC-PD could be successfully detected as a down-converted signal of 100 kHz. It suggests a potential to measure the electric field distributions of 1-D/2-D patch antenna arrays, used in advanced RoF systems.

Millimeter-Wave Radio-Over-Fiber Network for Linear Cell Systems

Kanno, Atsushi; Dat, Pham Tien; Yamamoto, Naokatsu; Kawanishi, Tetsuya; Kawanishi, Tetsuya

Journal of Lightwave Technology36(2)p.533 - 5402018年01月-2018年01月 

DOIScopus

詳細

ISSN:07338724

概要:© 2017 IEEE. We discuss and propose millimeter-wave linear cell systems for signal distribution on railway radiocommunication systems between train and trackside, and a foreign object debris detection system for airport runways using the radio-over-fiber network technology. Linear cell configurations based on wavelength-division multiplexing (WDM) and power-splitter-based distribution networks are discussed and demonstrated experimentally. A single-sideband modulation for data transmission in an intermediate frequency over a fiber system is successfully transmitted with an ultrafast wavelength-tunable laser diode for WDM routing to track the train car within 3 μs. Radar signal distribution by an optical double-sideband suppressed-carrier modulation mitigates the dispersion effect of the fiber cable to transmit a 32-GHz signal into the remote radar heads.

並列型LiNbO_3光変調器のバイアス制御方法に関する検討(量子効果デバイス(光信号処理、LD、光増幅、変調等)と集積化技術、一般「材料デバイスサマーミーティング」)

土屋 佑太;坂本 高秀;川西 哲也;中島 啓幾

電子情報通信学会技術研究報告. LQE, レーザ・量子エレクトロニクス110(103)p.31 - 352010年06月-2010年06月 

CiNii

詳細

ISSN:09135685

概要:我々のグループでは,LiNbO_3光変調器の基本構造となるマッハツェンダ型干渉構造の光入射側のY分岐部分に新たな電極を設置することで,光変調器の消光比を改善する報告を行った.今回これらの方法を多値変調技術に応用することを考え,並列型マッハツェンダ構造を有するLiNbO_3光変調器でのバイアス制御方法についてシミュレーションを行い確認した.また新たな電極構造を設置すると,その電極から発生する電界により光の位相変化が生じるため,その位相変化を考慮したバイアス制御方法が必要となる.本研究では実際にその位相変化の影響を実験によって確認し,その構造を並列型LiNbO_3光変調器の構造に導入するためのバイアス制御方法について検討した.

Auミラーを用いた共振型LiNbO_3光変調器の高効率・小型化(マイクロ波フォトニクス技術,一般)

高橋 優太;土屋 佑太;品田 聡;中島 慎也;川西 哲也;中島 啓幾

電子情報通信学会技術研究報告. MW, マイクロ波110(155)p.33 - 362010年07月-2010年07月 

CiNii

詳細

ISSN:09135685

概要:本研究では,光通信システムにおいて広く用いられているLiNbO_3光変調器の高効率・小型化を図ることを目的とする.その手法として,進行波型光変調器と比ペて小型であり狭帯域において高効率変調が可能である共振型LiNbO_3光変調器を用い,Auミラーによって光波を反射させ再び変調をかけることで高効率・小型化を図るものとする.今回,実際に作製し評価を行った結果,Auミラー反射を用いることによる高効率・小型化を確認した.

Auミラーを用いた共振型LiNbO_3光変調器の高効率・小型化(マイクロ波フォトニクス技術,一般)

高橋 優太;土屋 佑太;品田 聡;中島 慎也;川西 哲也;中島 啓幾

電子情報通信学会技術研究報告. OPE, 光エレクトロニクス110(156)p.33 - 362010年07月-2010年07月 

CiNii

詳細

ISSN:09135685

概要:本研究では,光通信システムにおいて広く用いられているLiNbO_3光変調器の高効率・小型化を図ることを目的とする.その手法として,進行波型光変調器と比ペて小型であり狭帯域において高効率変調が可能である共振型LiNbO_3光変調器を用い,Auミラーによって光波を反射させ再び変調をかけることで高効率・小型化を図るものとする.今回,実際に作製し評価を行った結果,Auミラー反射を用いることによる高効率・小型化を確認した.

干渉型光スイッチの高周波領域クロストークの評価および光強度トリマ構造による抑圧(光-無線融合NW、新周波数(波長)帯デバイス、フォトニックNW・デバイス、フォトニック結晶、ファイバとその応用、光集積回路、光導波路素子、光スイッチング、導波路解析、一般)

千葉 明人;川西 哲也;坂本 高秀;日隈 薫;高田 和正;井筒 雅之

電子情報通信学会技術研究報告. MWP, マイクロ波・ミリ波フォトニクス113(397)p.321 - 3242014年01月-2014年01月 

CiNii

詳細

ISSN:0913-5685

概要:本稿では、高周波信号により駆動された干渉型光スイッチのクロストークを評価する手法について述べる。光スイッチのドロップポートの出力に含まれるキャリア成分を利用するもので、時間領域測定における光検出器の利得帯域幅積の制約を回避することが可能である。この手法を用いて、干渉型光スイッチの各アームにマッハツェンダー構造を入れ子にした2x2光スイッチのクロストークを実験的に評価した結果も報告する。

干渉型光スイッチの高周波領域クロストークの評価および光強度トリマ構造による抑圧(光-無線融合NW、新周波数(波長)帯デバイス、フォトニックNW・デバイス、フォトニック結晶、ファイバとその応用、光集積回路、光導波路素子、光スイッチング、導波路解析、一般)

千葉 明人;川西 哲也;坂本 高秀;日隈 薫;高田 和正;井筒 雅之

電子情報通信学会技術研究報告. EST, エレクトロニクスシミュレーション113(396)p.321 - 3242014年01月-2014年01月 

CiNii

詳細

ISSN:0913-5685

概要:本稿では、高周波信号により駆動された干渉型光スイッチのクロストークを評価する手法について述べる。光スイッチのドロップポートの出力に含まれるキャリア成分を利用するもので、時間領域測定における光検出器の利得帯域幅積の制約を回避することが可能である。この手法を用いて、干渉型光スイッチの各アームにマッハツェンダー構造を入れ子にした2x2光スイッチのクロストークを実験的に評価した結果も報告する。

干渉型光スイッチの高周波領域クロストークの評価および光強度トリマ構造による抑圧(光-無線融合NW、新周波数(波長)帯デバイス、フォトニックNW・デバイス、フォトニック結晶、ファイバとその応用、光集積回路、光導波路素子、光スイッチング、導波路解析、一般)

千葉 明人;川西 哲也;坂本 高秀;日隈 薫;高田 和正;井筒 雅之

電子情報通信学会技術研究報告. OPE, 光エレクトロニクス113(394)p.321 - 3242014年01月-2014年01月 

CiNii

詳細

ISSN:0913-5685

概要:本稿では、高周波信号により駆動された干渉型光スイッチのクロストークを評価する手法について述べる。光スイッチのドロップポートの出力に含まれるキャリア成分を利用するもので、時間領域測定における光検出器の利得帯域幅積の制約を回避することが可能である。この手法を用いて、干渉型光スイッチの各アームにマッハツェンダー構造を入れ子にした2x2光スイッチのクロストークを実験的に評価した結果も報告する。

干渉型光スイッチの高周波領域クロストークの評価および光強度トリマ構造による抑圧(光-無線融合NW、新周波数(波長)帯デバイス、フォトニックNW・デバイス、フォトニック結晶、ファイバとその応用、光集積回路、光導波路素子、光スイッチング、導波路解析、一般)

千葉 明人;川西 哲也;坂本 高秀;日隈 薫;高田 和正;井筒 雅之

電子情報通信学会技術研究報告. LQE, レーザ・量子エレクトロニクス113(395)p.321 - 3242014年01月-2014年01月 

CiNii

詳細

ISSN:0913-5685

概要:本稿では、高周波信号により駆動された干渉型光スイッチのクロストークを評価する手法について述べる。光スイッチのドロップポートの出力に含まれるキャリア成分を利用するもので、時間領域測定における光検出器の利得帯域幅積の制約を回避することが可能である。この手法を用いて、干渉型光スイッチの各アームにマッハツェンダー構造を入れ子にした2x2光スイッチのクロストークを実験的に評価した結果も報告する。

Transmission of multiband wireless signals over a seamless IM/DD fiber-MMW system

Van Nguyen Toan;Dat Pham Tien;Kanno Atsushi;Yamamoto Naokatsu;Bao Vo Nguyen Quoc;Kawanishi Tetsuya

IEICE Electronics Express13(15)p.20160497 - 201604972016年-2016年

CiNii

詳細

概要:

This paper proposes a high-speed multiband filtered-orthogonal frequency division multiplexing (F-OFDM) signal transmission over a seamless fiber-millimeter-wave (MMW) system at 92.5 GHz. The system employs a frequency and phase stabilized optical MMW signal generation at the transmitter and a simple direct detection at the receiver. We confirm a successful transmission of multiband F-OFDM signal over a seamless 20-km single mode fiber (SMF) and 1-m 92.5-GHz wireless system. Compared to the single-band and multiband OFDM signal transmission, the proposed system can provide a much better performance, particularly at the edges of each band.

Low-latency fiber-wireless bridge for flexible fronthauling in future mobile networks

Dat, Pham Tien; Kanno, Atsushi; Kawanishi, Tetsuya

European Microwave Week 2015: "Freedom Through Microwaves", EuMW 2015 - Conference Proceedings; 2015 45th European Microwave Conference Proceedings, EuMCp.1156 - 11592015年12月-2015年12月 

DOIScopus

詳細

概要:© 2015 EuMA.We propose a flexible and low-latency cascaded fiber-wireless system for future mobile fronthauling using seamless combination of fiber-optic and millimeter-wave links. Successful transmission of intraband and interband carrier aggregation LTE-A signals over the system is experimentally confirmed. Satisfactory performance is achieved owing to the use of a high-quality optical millimeter-wave signal generation technique at the transmitter and a proposed high-performance self-homodyne detection at the receiver.

Optical frequency-interleaving full-duplex multichannel transmission of W-band frequency-modulated continuous-wave downlink signal and 10-Gb/s on-off-keying uplink signal

Kiri, Toshiaki; Kanno, Atushi; Kawanishi, Tetsuya; Kawanishi, Tetsuya

2015 International Topical Meeting on Microwave Photonics, MWP 2015 - Conference Proceedings2015年12月-2015年12月 

DOIScopus

詳細

概要:© 2015 IEEE.An optical frequency-interleaving full-duplex multi-channel transmission of W-band frequency-modulated continuous-wave downlink and 10-Gb/s on-off-keying uplink signals is investigated. Two-channel transmission with a flexible wavelength channel selector over 10-km-class fiber-optic network is experimentally demonstrated.

5G transport networks: The need for new technologies and standards

Dat, Pham Tien; Kanno, Atsushi; Yamamoto, Naokatsu; Kawanishi, Tetsuya; Kawanishi, Tetsuya

IEEE Communications Magazine54(9)p.18 - 262016年09月-2016年09月 

DOIScopus

詳細

ISSN:01636804

概要:© 1979-2012 IEEE.Mobile transport networks will play a vital role in future 5G and beyond networks. In particular, access transport networks connecting radio access with core networks are of critical importance. They will be required to support massive connectivity, super high data rates, and real-time services in a ubiquitous environment. To attain these targets, transport networks should be constructed on the basis of a variety of technologies and methods, depending on application scenarios, geographic areas, and deployment models. In this article, we present several technologies, including analog radio-over-fiber transmission, intermediate-frequency- over-fiber technology, radio-on-radio transmission, and the convergence of fiber and millimeter-wave systems, that can facilitate building such effective transport networks in many use cases. For each technology, we present the system concept, possible application cases, and demonstration results. We also discuss potential standardization and development directions so the proposed technologies can be widely used.

Demonstration of ultraprecision ductile-mode cutting for lithium niobate microring waveguides

Takigawa, Ryo; Higurashi, Eiji; Kawanishi, Tetsuya; Kawanishi, Tetsuya; Asano, Tanemasa

Japanese Journal of Applied Physics55(11)2016年11月-2016年11月 

DOIScopus

詳細

ISSN:00214922

概要:© 2016 The Japan Society of Applied Physics.In this paper, the application of the ultraprecision ductile-mode cutting method to the fabrication of microring waveguides in lithium niobate crystal was investigated. Although it was difficult to apply a mechanical cutting method to the fabrication of microring waveguides with smooth sidewalls, it was confirmed that no harmful cutting traces on the machined surface occur with the appropriate movement of the cutting tool. The root-meansquare surface roughness of the resulting sidewall was 6.1 nm, which is sufficiently small to suppress the scattering loss of the circulating light. In addition, the conditions for the ductile-mode cutting of lithium niobate crystal were investigated.

Seamless fiber-wireless bridge in the millimeter- and terahertz-wave bands

Kanno, Atsushi; Dat, Pham Tien; Sekine, Norihiko; Hosako, Iwao; Yamamoto, Naokatsu; Yoshida, Yuki; Kitayama, Ken Ichi; Kawanishi, Tetsuya; Kawanishi, Tetsuya

Journal of Lightwave Technology34(20)p.4794 - 48012016年10月-2016年10月 

DOIScopus

詳細

ISSN:07338724

概要:© 1983-2012 IEEE.Fiber-wireless transmission in the terahertz-wave band as well as in the millimeter-wave band is the key for a seamless integration of radio and optical networks in a physical layer. Advanced optical fiber communication technology enables a high precision direct waveform transfer between optical and radio domains. For realization of a seamless conversion, an optical-terahertz converter is configured with optical heterodyning for an optical-to-terahertz conversion. Analog optical modulation techniques by an input millimeter-wave signal and an intermediate frequency component after a frequency downconversion are utilized for a terahertz-to-optical conversion. A quadrature phase-shift keying signal transmission in an optical-fiber-to-radio-to-optical-fiber link (fiber-wireless bridge) is successfully demonstrated with the 90 and 300-GHz signals, simultaneously, using an optical frequency comb source. The possible transmission distance in severe weather conditions in these frequency bands is also discussed.

100-GHz Fiber-Fed Optical-To-Radio Converter for Radio-And Power-Over-Fiber Transmission

Umezawa, Toshimasa; Kashima, Kenichi; Kanno, Atsushi; Matsumoto, Atsushi; Akahane, Kouichi; Yamamoto, Naokatsu; Kawanishi, Tetsuya

IEEE Journal on Selected Topics in Quantum Electronics23(3)2017年05月-2017年05月 

DOIScopus

詳細

ISSN:1077260X

概要:© 1995-2012 IEEE. We have developed a 100-GHz fiber-fed optical-To-radio converter for radio-And power-over-fiber transmission. A zero-bias operational high-speed photodetector (3-dB bandwidth > 100 GHz) could be applied for the optical-To-radio converter, taking significant advantage of no-bias feed 100-GHz operation. We have successfully demonstrated simultaneous radio and power generation from one device through a bias-T circuit. A 100-GHz pseudomorphic high electron mobility transistor amplifier allowed a hybrid integrated photoreceiver to enhance the O/E conversion gain. Using the generated electric power, a gate bias in the 100-GHz amplifier was driven. The performance of each device and the integrated photoreceiver is described. High data rate photonic wireless transmission based on photonic power supply without external electric power supply is demonstrated.

書籍等出版物

高速高精度光変調の理論と実際 : 電気光学効果による光波制御

川西哲也(単著)

培風館2016年 06月-

LINK

詳細

単行本(学術書)総ページ数:177ISBN:978-4563067892

特許

整理番号:1922

障害物探知システム(日本)

川西 哲也

特願2017-113466、特開2018-205234

外部研究資金

科学研究費採択状況

研究種別:

High-Q共振器と光差周波発生を用いたミリ波・テラヘルツ波発生デバイスの開発

2012年-0月-2014年-0月

配分額:¥4030000

研究種別:

分極反転構造を用いた高機能電気光学変調器の開発

配分額:¥8300000

研究種別:

分極反転構造を用いた高機能電気光学変調器の開発

配分額:¥4000000

研究種別:

往復逓倍変調を利用した波長多重光無線信号一括発生技術に関する研究

配分額:¥30680000

研究種別:

ミリ波・光変換のためのアンテナ集積共振型光変調器アレイに関する研究

配分額:¥14900000

研究種別:

全光信号処理を廃した超高速光通信を実現する光時間周波数離散直交変換技術

2018年-0月-2023年-0月

配分額:¥43160000

研究種別:

非対称両側波帯光変調による無線信号周波数高速弁別

2018年-0月-2021年-0月

配分額:¥17550000

研究種別:

光・電波周波数コムを用いる高速測距技術に関する研究

2016年-0月-2019年-0月

配分額:¥4680000

研究種別:

半導体量子ドット2波長レーザによるテラヘルツ波発生

2015年-0月-2018年-0月

配分額:¥5070000

研究種別:

超高速・高密度光通信ネットワークのための光時間周波数領域直交多重・分離器

2015年-0月-2019年-0月

配分額:¥14300000

学内研究制度

特定課題研究

高精度光干渉デバイスによる通信・センシング両用技術に関する研究

2015年度

研究成果概要: 本研究課題は、超高消光比光干渉計をアクティブトリミング技術により実現し、集積デバイスとしての世界最高水準の精度の達成を目標としている。アクティブトリミングは導波路型MZ干渉計(マッハツェンダー型干渉計)の各アームに強度誤差を補正... 本研究課題は、超高消光比光干渉計をアクティブトリミング技術により実現し、集積デバイスとしての世界最高水準の精度の達成を目標としている。アクティブトリミングは導波路型MZ干渉計(マッハツェンダー型干渉計)の各アームに強度誤差を補正するための強度トリマーを持つ集積デバイスで実現される。強度トリマー自体もMZ干渉計で構成することが可能で、この場合既存の光変調デバイス作製プロセスが利用でき、実用性が高いが、トリミング用のバイアス電圧とメインのMZ干渉計のバイアス電圧を高精度に制御することが重要である。今年度はバイアス電圧制御アルゴリズム検討に注力し、動作の安定性と精度の高さの両立に適した制御方法を見出した。

高精度光干渉デバイスによる通信・センシング両用技術に関する研究

2015年度

研究成果概要: 本研究課題は、高消光比光干渉計をアクティブトリミング技術により実現し、通信用のデバイスとしての性能向上を実現するとともに動作モードを切り替えることで温度、圧力などの環境変化をモニタするためのセンシングデバイスとしての機能を持たせ... 本研究課題は、高消光比光干渉計をアクティブトリミング技術により実現し、通信用のデバイスとしての性能向上を実現するとともに動作モードを切り替えることで温度、圧力などの環境変化をモニタするためのセンシングデバイスとしての機能を持たせることを目指すものである。消光比は干渉計のバランスの高さを表す指標である。MZ干渉計を変調器として用いる際には信号発生の精度の高さを表す。センサーとして用いる場合には、感度の高さに相当する。今年度は達成可能な消光比の見積もりと、検出可能な光路変化についての基本的な関係の検討を行った。

往復逓倍変調による広帯域周波数掃引信号発生

2015年度

研究成果概要: 本研究課題の目標は往復逓倍変調による光領域におけるミリ波・テラヘルツ波を生成し、その周波数を広い帯域にわたって変化させる技術の確立である。 往復逓倍変調はデバイス内で有限回光を往復させることで低い周波数の入力信号から高い周波数成... 本研究課題の目標は往復逓倍変調による光領域におけるミリ波・テラヘルツ波を生成し、その周波数を広い帯域にわたって変化させる技術の確立である。 往復逓倍変調はデバイス内で有限回光を往復させることで低い周波数の入力信号から高い周波数成分の生成(逓倍)を可能とする。低位相雑音のミリ波、THz信号発生に適している。本研究ではこれに周波数掃引の機能を持たせることを目標とする。往復させるという原理のためこれまでは一定周波数が前提であったが、掃引と同期した変調器制御により、広帯域光周波数掃引信号発生を目指す。今年度は周波数可変の基本原理の検討と、他の基準信号発生方式との比較を行った。 

高調波光変調を用いたミリ波・テラヘルツ帯高安定広帯域掃引信号発生

2016年度

研究成果概要:本研究課題の目標は高精度な光変調を用いてミリ波・テラヘルツ波を生成し、その周波数を広い帯域にわたって変化させる技術の確立である。 周波数掃引信号は高精度FMCWレーダーを実現するための重要な要素技術である。中間周波数帯で精度の高い...本研究課題の目標は高精度な光変調を用いてミリ波・テラヘルツ波を生成し、その周波数を広い帯域にわたって変化させる技術の確立である。 周波数掃引信号は高精度FMCWレーダーを実現するための重要な要素技術である。中間周波数帯で精度の高い周波数掃引信号発生技術の開発し、特に、同時に発生する複数の信号の取り扱いについて詳細の検討を行った。複数のFMCWレーダー間で発生しうる干渉について検討し、掃引時間を制御することで、不要なノイズ発生を抑えることが可能であることを示した。本研究課題では中間周波数帯における原理確認を行ったが、今後はミリ波帯信号を用いた実証実験の準備に取りかかる予定である。 

光伝搬遅延とデータ通信需要の関係の探求

2017年度

研究成果概要: 本研究の目的は、光速が有限であり、当面、人類が地球上で生活するということを前提とした場合の、シーズとしての伝送技術における低遅延化の限界を理論、実験の両面から求め、一定の遅延が不可避であるという条件下でのニーズとしての情報通信需... 本研究の目的は、光速が有限であり、当面、人類が地球上で生活するということを前提とした場合の、シーズとしての伝送技術における低遅延化の限界を理論、実験の両面から求め、一定の遅延が不可避であるという条件下でのニーズとしての情報通信需要の上限を探ることである。情報伝達は光速を越えることは不可能であるので、太平洋横断光ファイバーケーブルなどの長距離伝送を介したネットワーク上ではオンラインゲームなどの即時性を要求するアプリケーションでは大きな影響を生じる。この理論上の絶対限界に近づくための光ファイバシステムの構成と、理論限界を超えるためのアプリケーション上の工夫について基礎検討を行っている。

高調波光変調によるミリ波・テラヘルツ波の高精度周波数制御と並列信号処理への応用

2017年度

研究成果概要:光変調器の非線形性を用いた高調波発生による周波数逓倍は低雑音であることが知られており、ミリ波、THz信号発生に適している。本研究ではこれに周波数掃引、周波数切り替えの機能を持たせることを目標とした。高調波成分の生成効率を重視した従...光変調器の非線形性を用いた高調波発生による周波数逓倍は低雑音であることが知られており、ミリ波、THz信号発生に適している。本研究ではこれに周波数掃引、周波数切り替えの機能を持たせることを目標とした。高調波成分の生成効率を重視した従来の手法では一定周波数が前提であったが、掃引と同期した変調器制御により、広帯域光周波数掃引信号発生を目指した。ミリ波帯レーダなどへの応用を想定して、掃引の高速性、周波数の安定度の両立を目指した基本設計を行った。また、周波数切り替えによるスペクトル制御とマルチコアファイバを組み合わせた空間的光信号処理を提案し、並列的演算システムの構成を検討した。

マイクロ波・ミリ波同時利用レーダー技術の研究

2018年度共同研究者:菅野敦史, 稲垣惠三

研究成果概要: 本研究の目的は、見通し外の障害物を検知するためのレーダーの実現である。現在、交通事故の抑止、さらには自動運転の実現を目指して、自動車の周辺状況をセンシングするための技術開発が精力的に行われている。カメラやミリ波レーダーを用いた低... 本研究の目的は、見通し外の障害物を検知するためのレーダーの実現である。現在、交通事故の抑止、さらには自動運転の実現を目指して、自動車の周辺状況をセンシングするための技術開発が精力的に行われている。カメラやミリ波レーダーを用いた低コストで有効な衝突防止システムが実現しつつある。しかし、これらのすべてが見通し内の障害物に対するものであり、見通しがきかないところの状況を把握するための技術の開発例は少なく、研究開発の難易度も高い。交差点などにレーダーを設置し、見通し外の障害物を自動車などに通知するシステムの開発も進められているが、狭隘な路地すべてに複雑なシステムを整備するのは困難である。 そこで本研究では、比較的低い周波数の電波で視野外障害物を検知するとともに、現在すでに各社が開発し実用が進むミリ波レーダーやカメラによる視野内検知技術を組み合わせる方式を提案している。今年度はマイクロ波帯2次レーダーの基本原理と見通し外の障害物検知能力の確認を行った。

現在担当している科目

科目名開講学部・研究科開講年度学期
理工学基礎実験2A 電子物理基幹理工学部2019春学期
電子物理システム概論基幹理工学部2019春学期
電子物理システム概論 【前年度成績S評価者用】基幹理工学部2019春学期
電磁気学A基幹理工学部2019春学期
電磁気学A  【前年度成績S評価者用】基幹理工学部2019春学期
電子物理システム演習A基幹理工学部2019春学期
電子物理システム演習A 【前年度成績S評価者用】基幹理工学部2019春学期
電子物理システム実験A基幹理工学部2019秋学期
電子物理システム実験A 【前年度成績S評価者用】基幹理工学部2019秋学期
電子物理システム実験B基幹理工学部2019春学期
電子物理システム実験B 【前年度成績S評価者用】基幹理工学部2019春学期
電子物理システム実験C基幹理工学部2019秋学期
電子物理システム実験C 【前年度成績S評価者用】基幹理工学部2019秋学期
電子物理システム特別演習基幹理工学部2019秋学期
卒業論文A基幹理工学部2019春学期
卒業論文A基幹理工学部2019秋学期
卒業論文A  【前年度成績S評価者用】基幹理工学部2019春学期
卒業論文B基幹理工学部2019秋学期
卒業論文B基幹理工学部2019春学期
卒業論文B  【前年度成績S評価者用】基幹理工学部2019秋学期
マイクロ波フォトニクス基幹理工学部2019秋学期
Research Project B基幹理工学部2019春学期
Research Project B 【前年度成績S評価者用】基幹理工学部2019春学期
Research Project C基幹理工学部2019秋学期
Research Project C 【前年度成績S評価者用】基幹理工学部2019秋学期
Research Project A基幹理工学部2019秋学期
Research Project D基幹理工学部2019春学期
修士論文(電子)大学院基幹理工学研究科2019通年
Research on Radio and Optical Converged Systems大学院基幹理工学研究科2019通年
光電波融合システム研究大学院基幹理工学研究科2019通年
Radio and Optical Converged Systems大学院基幹理工学研究科2019秋学期
光電波融合システム大学院基幹理工学研究科2019秋学期
Seminar on Radio and Optical Converged Systems A大学院基幹理工学研究科2019春学期
光電波融合システム演習A大学院基幹理工学研究科2019春学期
Seminar on Radio and Optical Converged Systems B大学院基幹理工学研究科2019秋学期
光電波融合システム演習B大学院基幹理工学研究科2019秋学期
Seminar on Radio and Optical Converged Systems C大学院基幹理工学研究科2019春学期
光電波融合システム演習C大学院基幹理工学研究科2019春学期
Seminar on Radio and Optical Converged Systems D大学院基幹理工学研究科2019秋学期
光電波融合システム演習D大学院基幹理工学研究科2019秋学期
光電波融合システム研究大学院基幹理工学研究科2019通年