JP3825415B2

JP3825415B2 - Optical wavelength division multiplexing transmission interface equipment

Info

Publication number: JP3825415B2
Application number: JP2003088592A
Authority: JP
Inventors: 一人野口; 顕岡田; 博正田野辺; 茂登松岡; 摂森脇; 尊坂本
Original assignee: Nippon Telegraph and Telephone Corp
Current assignee: Nippon Telegraph and Telephone Corp
Priority date: 2003-03-27
Filing date: 2003-03-27
Publication date: 2006-09-27
Anticipated expiration: 2023-03-27
Also published as: JP2004297559A

Description

【０００１】
【発明の属する技術分野】
本発明は、光波長分割多重伝送インタフェース装置に関し、特に多波長光源装置の構成技術に関する。
【０００２】
【従来の技術】
複数の光信号に異なる光周波数を割り当て、これらを１本の光ファイバで伝送する光波長分割多重（ＷＤＭ）伝送システムは、伝送容量を大幅に増大することができる。
【０００３】
図５は、その光波長分割多重伝送システムに用いられる従来の光波長分割多重伝送インタフェース装置を示すブロック図である。この光波長分割多重伝送インタフェース装置は、複数の上り入力端子５０１と、これらの上り入力端子５０１ごとに設けられた複数の単波長光源器５０２と、これらの単波長光源器５０２からの各波長の光信号を合波する光合波器５０３と、合波した光信号の上り出力端子５０４とを順次直列に接続して構成した送信部を有する。
【０００４】
また、光波長分割多重伝送インタフェース装置は、下り入力端子５０５と、下り入力端子５０５からの光信号を分波する光分波器５０６と、この光分波器５０６からの複数の波長毎の出力を受光する複数の単波長受光器５０７と、それぞれの単波長受光器５０７ごとに設けられた下り出力端子５０８とを順次直列に接続して構成した受信部を有する（例えば、特許文献１参照）。
【０００５】
従って、前記構成によれば、上り入力端子５０１から波長が異なる複数の光入力信号を入力すると、単波長光源器５０２は、あらかじめ設定されたそれぞれ異なる所定の周波数の光信号を、前記光入力信号にそれぞれ対応した振幅で発振する。また、各光波長光源器５０２からの光信号を、光合波器５０３で合波することで一つの多波長光信号にし、一つの上り出力端子５０４を通じて外部へ出力する。
【０００６】
また、光波長分割多重伝送インタフェース装置において、一つの多波長光信号を外部から一つの下り入力端子５０５を通じて受信すると、その受信光信号が光分波器５０６で分波され、それぞれ波長の異なる単波長の複数の受信光信号とされる。これら波長の異なる複数の受信光信号は単波長受光器５０７で受信され、得られた光信号を複数の下り出力端子５０８を通じてそれぞれ出力する。
【０００７】
ここで、単波長光源器５０２として半導体レーザが、光合波器５０３、光分波器５０６としてアレイ導波路回折格子が、それぞれ一般に用いられる。半導体レーザは素子温度の１℃の変化に対して、発振波長が０．１ｎｍ変化する。アレイ導波路回折格子の透過帯域は１ｎｍ変化する。このため、引用文献１に記載されているように、光信号を取り出すために半導体レーザの素子温度を精密に調整する必要がある。
【０００８】
【特許文献１】
特開２００１−２４９２３６号公報
【０００９】
【発明が解決しようとする課題】
しかしながら、従来の光波長分割多重伝送インタフェース装置では、これを外部の装置と接続するのに、上りに１本、下りに１本で合計２本の光ファイバが必要になる。光通信サービスにおいては、使用する光ファイバのコストは光ファイバの本数と距離に比例するため、低廉なサービスを提供するためには使用する光ファイバの本数を減らす必要があった。
【００１０】
また、半導体レーザの素子温度の調整には、半導体レーザやアレイ導波路回折格子のチップの収容ケースの中に、サーミスタなどの温度検知素子、およびペルチェ素子などの温度調整素子を配置し、さらに温度制御用の外部制御回路を設ける必要があった。このため、素子自体が高価であることと合わせて、装置のコストが非常に高くなる。
【００１１】
本発明は、かかる従来の問題点に鑑みてなされたものであり、その目的は、外部との接続に使用する光ファイバが１本で済み、かつ温度調整機構を備える必要がなく、光通信サービスのコストを低減できる光波長分割多重伝送インタフェース装置を提供することにある。
【００１２】
【課題を解決するための手段】
前記目的達成のために、請求項１の発明にかかる光波長分割多重伝送インタフェース装置は、外部から入力された複数の光信号をそれぞれ受信し、該光信号に対応した強度のそれぞれ異なる所定の波長の光信号を出力する複数の単波長光源器と、該複数の単波長光源器からの複数の光信号を合波して一つの多波長光信号として出力する光合波器と、それぞれ波長の異なる複数の光信号が合波された一つの多波長光信号を波長毎に分波して波長の異なる複数の光信号として出力する光分波器と、該光分波器からの波長の異なる複数の光信号をそれぞれ受信し、増幅・波形整形して出力する複数の単波長受光器と、前記光合波器の出力部と光分波器の入力部と外部とを、光合波器の出力部からの光信号が外部に出力され、外部から入力された光信号が光分波器の入力部に入力される如く接続する光合分流器とを具備し、前記光分波器及び光合波器の透過帯域が９ｎｍ以上であり、かつ前記透過帯域の中心波長がＩＴＵ−Ｔグリッド波長より１ｎｍ長波長側にずらされていることを特徴とする。
【００１３】
これにより、インタフェース装置を外部の装置と接続する光ファイバの使用量を半減でき、光波長分割多重伝送装置および光通信サービスを廉価に提供することができる。また、この結果、従来行われていた送信部における半導体レーザの温度制御のための、温度検知素子や温度制御（調整）素子を用意する必要がなくなり、温度変動を許容しながら透過帯域幅を必要最低減にでき、装置のコスト上昇を回避することができる。
【００１４】
また、請求項３の発明にかかる光波長分割多重伝送インタフェース装置は、外部から入力された複数の光信号をそれぞれ受信し、該光信号に対応した強度のそれぞれ異なる所定の波長の光信号を出力する複数の単波長光源器と、波長の異なる複数の光信号をそれぞれ受信し、増幅・波形整形して出力する複数の単波長受光器と、複数のポートに入力されたそれぞれ波長の異なる複数の光信号を合波して一つの多波長光信号として外部へ出力し、かつ外部から入力された一つの多波長信号を波長毎に分波して波長の異なる複数の光信号として複数のポートへ出力する光合分波器と、前記複数の単波長光源器の出力部と複数の単波長受光器の入力部と光合分波器の複数のポートとを、単波長光源器の出力部からの光信号が光合分波器に入力され、光合分波器から出力された光信号が単波長受光器の入力部に入力される如くそれぞれ接続する複数の光合分流器とを具備し、前記光合分波器の透過帯域が９ｎｍ以上であり、かつ前記透過帯域の中心波長がＩＴＵ−Ｔグリッド波長より１ｎｍ長波長側にずらされていることを特徴とする。
【００１５】
これにより、光分波器と光合波器とをユニット化して、ユニット化された光合分波器の回路配置、接続、取扱いを容易にできるとともに、光ファイバの使用量を大幅に低減できる。
【００１６】
また、請求項５の発明にかかる光波長分割多重伝送インタフェース装置は、前記光合分流器が光カプラであることを特徴とする。これにより、光合分流動作を低損失にて実現できる。
【００１７】
また、請求項６の発明にかかる光波長分割多重伝送インタフェース装置は、前記光合分流器が光サーキュレータであることを特徴とする。これにより、光合分流動作を低損失にて実現できる。
【００１８】
また、請求項７の発明にかかる光波長分割多重伝送インタフェース装置は、外部から入力された複数の光信号をそれぞれ受信し、該光信号に対応した強度のそれぞれ異なる所定の波長の光信号を出力する複数の単波長光源器と、波長の異なる複数の光信号をそれぞれ受信し、増幅・波形整形して出力する複数の単波長受光器と、前記複数の単波長光源器からの複数の光信号を合波して一つの多波長光信号として外部へ出力し、かつ外部から入力された一つの多波長信号を波長毎に分波して波長の異なる複数の光信号として前記複数の単波長受光器へ入力する光合分波器とを具備し、前記光合分波器の透過帯域が９ｎｍ以上であり、かつ前記透過帯域の中心波長がＩＴＵ−Ｔグリッド波長より１ｎｍ長波長側にずらされていることを特徴とする。
【００１９】
これにより、光合分流器の使用を省略でき、装置コストの大幅な低減を図ることができる。
【００２１】
また、請求項２、４及び８の発明にかかる光波長分割多重伝送インタフェース装置は、それぞれ請求項１、３及び７の発明にかかる光波長分割多重伝送インタフェース装置において単波長受光器を省略したことを特徴とし、これによって構成の簡素化とコストの低減を実現できる。
【００２２】
【発明の実施の形態】
以下、本発明の実施の形態を図面を参照して詳しく説明する。
【００２３】
図１は、本発明の第１の実施の形態による光波長分割多重伝送インタフェース装置を示すブロック図である。このインタフェース装置は、複数の上り入力端子１０１と、これらに対応する波長特性を有する複数の単波長光源器１０２と、これらの単波長光源器１０２からの各波長の光信号を合波する光合波器１０３と、これらの光合波器１０３の上り出力端子１０４と、光合分流器１１０と、光信号入出力用の光端子１０９とを、順次直列接続して構成した送信部を有する。
【００２４】
また、前記インタフェース装置は、前記光端子１０９と、光合分流器１１０と、下り入力端子１０５、下り入力端子１０５からの光信号を分波する光分波器１０６と、この光分波器１０６の複数の波長出力にそれぞれ対応して設けられた複数の単波長受光器と、これらの単波長受光器１０７に対応する複数の下り出力端子１０８とを順次直列に接続して構成した受信部を有する。
【００２５】
次に動作について説明する。上り入力端子１０１のそれぞれから波長の異なる光入力信号を入力すると、単波長光源器１０２はあらかじめ設定されたそれぞれ異なる所望の周波数の光信号を、前記光入力信号にそれぞれ対応した振幅で発振する。また、各単波長光源器１０２からの複数の光信号を光合波器１０３で合波することで一つの多波長光信号にし、一つの上り出力端子１０４へ出力する。さらに、その上り出力端子１０４から多波長光信号を光合分流器１１０を通じて光端子１０９へ出力する。
【００２６】
一方、前記インタフェース装置は外部から供給される一つの多波長光信号を光端子１０９、光合分流器１１０、下り入力端子１０５を通じて受信する。光分波器１０６はその多波長光信号を受信光信号として受けて、これを分波して、それぞれ波長の異なる複数の受信光信号とする。単波長受光器１０７は、それらの複数の受信光信号を複数の下り出力端子１０８を通じてそれぞれ出力する。この結果、一つの光端子および光ファイバを通じて外部との光信号の送受信が可能になり、インタフェース装置を外部の装置と接続する光ファイバの使用量を半減でき光波長分割多重伝送システムおよび光通信サービスを廉価に提供することができる。
【００２７】
ところで、単波長光源器１０２に用いられる温度制御機構のないＣＷＤＭ用半導体レーザは、例えば、図２に示すように２０ｎｍ間隔のＩＴＵ−Ｔグリッド波長に対し、一定の波長ばらつきを持つ状態で製造、検査されて出荷される。図２ではこの波長ばらつきを±２ｎｍとした。実際の使用状態では、これらの半導体レーザを駆動回路と共に光インタフェース装置に組み込み、信号を入力して動作状態にするために、ドライバ回路や半導体レーザに数１０〜数１００ｍＡの電流を流す必要がある。
【００２８】
その結果、半導体レーザの素子温度が１０〜１５℃程度上昇し、半導体レーザの発振波長は１〜１．５ｎｍ長波長側にシフトする。さらに、装置の設置環境温度が５０℃まで上昇した場合、素子温度は６５℃程度まで上昇するため、レーザの発振波長は、初期ばらつきを考慮すると最大６ｎｍ長波長側にシフトすることがわかる。同様に、光インタフェース装置の設置環境温度が０℃程度まで下降した場合、半導体レーザの発振波長は最大３ｎｍ短波長側にシフトする。
【００２９】
従って、図２に示すように、光合波器１０３、光分波器１０６の透過帯域の中心波長を長波長側に１ｎｍずらし、透過帯域幅を９ｎｍ以上に設定することにより、前記温度変化による波長シフトをカバーできる。この結果、インタフェース装置の設置場所の環境温度が０〜５０℃の間で変化することによって、半導体レーザの発振波長がシフトしても、インタフェース機能を保持することが可能になる。この結果、従来行われていた送信部における半導体レーザの温度制御のための、温度検知素子や温度制御（調整）素子を用意する必要がなくなり、温度変動を許容しながら透過帯域幅を必要最低限とし、装置のコスト上昇を回避することができる。
【００３０】
図３は、本発明の第２の実施の形態による光波長分割多重伝送インタフェース装置を示すブロック図である。このインタフェース装置は、複数の上り入力端子３０１と、これらに対応する波長特性を持った複数の単波長光源器３０２と、複数の光合分流器３１０と、光合分波器３０３と、光端子３０９とを順次直列接続して構成した送信部を有する。
【００３１】
また、前記インタフェース装置は、光端子３０９と、光合分波器３０３と、この光合分波器３０３で分波された複数の波長出力にそれぞれ対応する複数の光合分流器３１０と、光合分流器３１０で分流された各波長ごとの光信号を受光する単波長受光器３０７と、これらの単波長受光器３０７に対応する下り出力端子３０８とを順次直列接続して構成した受信部を有する。
【００３２】
この第２の実施の形態によるインタフェース装置においては、まず、上り入力端子３０１からそれぞれ波長の異なる光入力信号を入力すると、単波長光源器３０２はあらかじめ設定されたそれぞれ異なる所定の周波数の光信号を、前記光入力信号にそれぞれ対応した振幅で発振する。この発振されて出力された複数の光信号を光合分流器３１０を通して光合分波器３０３へ出力し、この光合分波器３０３でこれらの光信号を合波する。これにより一つの多波長光信号が得られ、一つの光端子３０９から外部へ出力される。
【００３３】
一方、インタフェース装置は、外部からの一つの多波長光信号を一つの光端子３０９を通じて受信すると、その受信光信号を光合分波器３０３で分波し、波長の異なる複数の受信光信号とする。さらに、これら波長の異なる複数の受信光信号を、光合分流器３１０を通して単波長受光器３０７が受け、この単波長受光器３０７で受けた光信号を複数の下り出力端子３０８を通じてそれぞれ出力する。
【００３４】
従って、この第２の実施の形態では、単波長光源器３０２および単波長受光器３０７と光合分波器３０３とを光合分流器３１０を介して結ぶ光ファイバの使用量をさらに低減でき、装置および通信サービスの提供をより廉価に行うことができる。また、図１に示すような光合波器１０３と光分波器１０６を１つの光合分波器３０３にまとめることで、回路配置、接続、取扱いが容易となりコストの低減を図ることができる。
【００３５】
図４は、本発明の第３の実施の形態による光波長分割多重伝送インタフェース装置の概略構成を示している。この光波長分割多重伝送インタフェース装置は、複数の上り入力端子４０１と、これらに対応する波長特性を持った複数の単波長光源器４０２と、光合分波器４０４と、光端子４０９とを順次直列接続して構成した送信部を有する。
【００３６】
また、このインタフェース装置は、前記光端子４０９と、光合分波器４０４とこの光合分波器４０３で分波された複数の波長出力にそれぞれ対応する複数の単波長受光器４０７と、これらの単波長受光器４０７に対応する複数の下り出力端子４０８とを順次直列接続して構成した受信部を有する。
【００３７】
この第３の実施の形態によるインタフェース装置においては、まず上り入力端子４０１からそれぞれ波長の異なる光入力信号を入力すると、単波長光源器４０２は、あらかじめ設定されたそれぞれ異なる所定の周波数の光信号を、前記光入力信号にそれぞれ対応した振幅で発振する。この発振されて出力された複数の光信号を光合分波器４０４が受け、この光合分波器４０３は各光出力を合波することで、一つの多波長光信号にまとめて、一つの光端子４０９を介して外部へ出力する。
【００３８】
一方、インタフェース装置は外部から一つの多波長光信号を一つの端子４０９を通じて受信すると、その受信光信号を光合分波器４０４が分波して波長の異なる複数の受信光信号とする。これらの波長の異なる複数の受信光信号は単波長受光器４０７に入力され、この単波長受光器４０７で得られた光信号を複数の下り出力端子４０８を通じてそれぞれ出力する。
【００３９】
図３に示すような光合分流器３１０と光合分波器３０３を１つの光合分波器４０４で兼ねることで、回路配置、接続、取扱いが容易となり、コストの低減を図ることができる。
【００４０】
以上の各実施の形態では、従来の装置と異なって、単波長光源器１０２、３０２、４０２、光合波器１０３、光分波器１０６および光合分波器３０３、４０４がそれぞれペルチェ素子、サーミスタなどの温度調整機構のない安価な部品で構成されている。このため、本インタフェース装置は温度調整のための制御回路を設けておらず、従って消費電力が小さく、低コストで作成することができる。
【００４１】
なお、以上の各実施の形態において、光合分流器として、光カプラあるいは光サーキュレータを用いることができる。また、以上の各実施の形態において、単波長受光器を省略し、波長多重された光信号をそのまま下り出力端子を通じて出力する構成にしても同様の効果を得ることができる。
【００４２】
【発明の効果】
以上のように、本発明によれば光波長分割多重伝送インタフェース装置と外部装置とを結ぶ光信号伝送用の光ファイバを、光合分波器や光合分流器を用いることによって１本のみとすることにより、光ファイバの配線量を大幅に低減でき、従って光波長分割多重伝送システムおよび光通信サービスを廉価に提供できる。さらに、半導体レーザの温度制御をすることに代えて波長発振のシフトを必要最低限の透過帯域幅内で許容することで、従来のような温度検出や温度制御のための温度調整機構や回路を別途設ける必要がなくなり、また装置の小形化およびコストの低減を実現できるという効果が得られる。
【図面の簡単な説明】
【図１】本発明の光波長分割多重伝送インタフェース装置の第１の実施の形態を示すブロック図
【図２】本発明の実施の形態の動作を示す動作説明図
【図３】本発明の光波長分割多重伝送インタフェース装置の第２の実施の形態を示すブロック図
【図４】本発明の光波長分割多重伝送インタフェース装置の第３の実施の形態を示すブロック図
【図５】従来の光波長分割多重伝送インタフェース装置の一例を示すブロック図
【符号の説明】
１０２，３０２，４０２：単波長光源器、１０３：光合波器、１０６：光分波器、１０７，３０７，４０７：単波長受光器、１１０，３１０：光合分流器、３０３，４０４：光合分波器。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical wavelength division multiplex transmission interface device, and more particularly to a configuration technology of a multi-wavelength light source device.
[0002]
[Prior art]
An optical wavelength division multiplexing (WDM) transmission system that assigns different optical frequencies to a plurality of optical signals and transmits them through a single optical fiber can greatly increase the transmission capacity.
[0003]
FIG. 5 is a block diagram showing a conventional optical wavelength division multiplexing transmission interface apparatus used in the optical wavelength division multiplexing transmission system. This optical wavelength division multiplexing transmission interface apparatus includes a plurality of upstream input terminals 501, a plurality of single wavelength light source devices 502 provided for each of these upstream input terminals 501, and wavelength of each wavelength from these single wavelength light source devices 502. An optical multiplexer 503 for multiplexing optical signals and an upstream output terminal 504 for the combined optical signals are sequentially connected in series to have a transmission unit.
[0004]
Further, the optical wavelength division multiplexing transmission interface apparatus includes a downlink input terminal 505, an optical demultiplexer 506 that demultiplexes an optical signal from the downlink input terminal 505, and an output for each of a plurality of wavelengths from the optical demultiplexer 506. A receiving unit configured by sequentially connecting a plurality of single-wavelength light receivers 507 and a downstream output terminal 508 provided for each single-wavelength light receiver 507 in series (see, for example, Patent Document 1). .
[0005]
Therefore, according to the above configuration, when a plurality of optical input signals having different wavelengths are input from the upstream input terminal 501, the single wavelength light source device 502 converts optical signals having different predetermined frequencies set in advance to the optical input signal. Oscillates with the amplitude corresponding to each. Further, the optical signals from the respective optical wavelength light source devices 502 are combined by the optical multiplexer 503 into one multi-wavelength optical signal, which is output to the outside through one upstream output terminal 504.
[0006]
Further, in the optical wavelength division multiplexing transmission interface device, when one multi-wavelength optical signal is received from the outside through one downlink input terminal 505, the received optical signal is demultiplexed by the optical demultiplexer 506, and each single wavelength is different. A plurality of received optical signals having wavelengths are used. A plurality of received optical signals having different wavelengths are received by the single wavelength receiver 507, and the obtained optical signals are output through the plurality of downstream output terminals 508, respectively.
[0007]
Here, a semiconductor laser is generally used as the single wavelength light source 502, and an arrayed waveguide diffraction grating is generally used as the optical multiplexer 503 and the optical demultiplexer 506, respectively. In the semiconductor laser, the oscillation wavelength changes by 0.1 nm with respect to a change in element temperature of 1 ° C. The transmission band of the arrayed waveguide grating changes by 1 nm. For this reason, as described in Patent Document 1, it is necessary to precisely adjust the element temperature of the semiconductor laser in order to extract an optical signal.
[0008]
[Patent Document 1]
Japanese Patent Laid-Open No. 2001-249236
[Problems to be solved by the invention]
However, in the conventional optical wavelength division multiplex transmission interface device, in order to connect this to an external device, a total of two optical fibers are required, one for upstream and one for downstream. In optical communication services, the cost of optical fibers to be used is proportional to the number of optical fibers and the distance. Therefore, it has been necessary to reduce the number of optical fibers to be used in order to provide inexpensive services.
[0010]
In order to adjust the element temperature of the semiconductor laser, a temperature detecting element such as a thermistor and a temperature adjusting element such as a Peltier element are arranged in the housing case of the chip of the semiconductor laser or the arrayed waveguide grating, and the temperature is further increased. It was necessary to provide an external control circuit for control. For this reason, the cost of the apparatus becomes very high together with the fact that the element itself is expensive.
[0011]
The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a single optical fiber used for connection to the outside, and it is not necessary to provide a temperature adjustment mechanism. It is an object to provide an optical wavelength division multiplex transmission interface apparatus capable of reducing the cost of the above.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, an optical wavelength division multiplexing transmission interface apparatus according to the first aspect of the present invention receives a plurality of optical signals input from the outside, and receives predetermined wavelengths having different intensities corresponding to the optical signals. A plurality of single-wavelength light source devices that output a plurality of optical signals, and an optical multiplexer that combines a plurality of optical signals from the plurality of single-wavelength light source devices and outputs them as one multi-wavelength optical signal, respectively. An optical demultiplexer that demultiplexes one multi-wavelength optical signal combined with a plurality of optical signals for each wavelength and outputs them as a plurality of optical signals having different wavelengths, and a plurality of wavelengths different from the optical demultiplexers A plurality of single wavelength receivers that respectively receive and amplify and shape the waveform, and output the optical multiplexer, the input and the external of the optical demultiplexer, and the output of the optical multiplexer The optical signal from the outside is output to the outside, and the optical signal input from the outside There comprising an optical multiplexer diverter for connecting as input to the input portion of the optical demultiplexer, the transmission band of the optical demultiplexer and the optical multiplexer is a 9nm or more, and the center wavelength of the transmission band ITU It is characterized by being shifted from the T grid wavelength by 1 nm longer wavelength side.
[0013]
As a result, the amount of optical fiber used to connect the interface device to an external device can be halved, and the optical wavelength division multiplexing transmission device and the optical communication service can be provided at low cost. As a result, it is no longer necessary to prepare a temperature detection element or temperature control (adjustment) element for temperature control of the semiconductor laser in the transmitter, which has been conventionally performed, and a transmission bandwidth is required while allowing temperature fluctuations. The minimum cost can be reduced, and an increase in the cost of the apparatus can be avoided.
[0014]
The optical wavelength division multiplexing transmission interface apparatus according to the invention of claim 3 receives a plurality of optical signals input from the outside, and outputs optical signals of predetermined wavelengths having different intensities corresponding to the optical signals. A plurality of single-wavelength light sources, a plurality of single-wavelength receivers that receive and amplify and waveform-shape a plurality of optical signals having different wavelengths, and a plurality of different wavelengths input to a plurality of ports. Optical signals are combined and output to the outside as a single multi-wavelength optical signal, and one multi-wavelength signal input from the outside is demultiplexed for each wavelength and output to multiple ports as multiple optical signals with different wavelengths An optical multiplexer / demultiplexer for outputting, an output unit of the plurality of single wavelength light source units, an input unit of the plurality of single wavelength receiver units, and a plurality of ports of the optical multiplexer / demultiplexer, light from the output unit of the single wavelength light source unit The signal is input to the optical multiplexer / demultiplexer, And a plurality of optical multiplexer diverter optical signal output from the demultiplexer is connected as input to the input portion of the single-wavelength light receiver, the transmission band of the optical demultiplexer is located above 9nm The center wavelength of the transmission band is shifted to the wavelength side longer by 1 nm than the ITU-T grid wavelength.
[0015]
As a result, the optical demultiplexer and the optical multiplexer can be unitized to facilitate circuit arrangement, connection, and handling of the unitized optical multiplexer / demultiplexer, and the amount of optical fiber used can be greatly reduced.
[0016]
The optical wavelength division multiplexing transmission interface apparatus according to the invention of claim 5 is characterized in that the optical multiplexer / demultiplexer is an optical coupler. Thereby, the optical combining / dividing operation can be realized with low loss.
[0017]
The optical wavelength division multiplexing transmission interface apparatus according to the invention of claim 6 is characterized in that the optical multiplexer / demultiplexer is an optical circulator. Thereby, the optical combining / dividing operation can be realized with low loss.
[0018]
The optical wavelength division multiplexing transmission interface apparatus according to the invention of claim 7 receives a plurality of optical signals input from the outside, and outputs optical signals of predetermined wavelengths having different intensities corresponding to the optical signals. A plurality of single-wavelength light source devices, a plurality of single-wavelength light receivers that respectively receive a plurality of optical signals having different wavelengths, amplify and shape the waveform, and a plurality of optical signals from the plurality of single-wavelength light source devices. Are combined and output to the outside as a single multi-wavelength optical signal, and the single multi-wavelength light received as a plurality of optical signals having different wavelengths by demultiplexing one multi-wavelength signal input from the outside for each wavelength. An optical multiplexer / demultiplexer that inputs to the optical filter , the transmission band of the optical multiplexer / demultiplexer is 9 nm or more, and the center wavelength of the transmission band is shifted to the longer wavelength side by 1 nm than the ITU-T grid wavelength. It is characterized by
[0019]
Thereby, the use of the optical combiner / divider can be omitted, and the apparatus cost can be greatly reduced.
[0021]
The optical wavelength division multiplex transmission interface apparatus according to the inventions of claims 2, 4 and 8 omits the single wavelength receiver in the optical wavelength division multiplex transmission interface apparatus according to the inventions of claims 1, 3 and 7, respectively. This makes it possible to simplify the configuration and reduce the cost.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0023]
FIG. 1 is a block diagram showing an optical wavelength division multiplexing transmission interface apparatus according to the first embodiment of the present invention. This interface device includes a plurality of upstream input terminals 101, a plurality of single wavelength light source devices 102 having wavelength characteristics corresponding to them, and an optical multiplexing device that combines optical signals of respective wavelengths from these single wavelength light source devices 102. And an optical output terminal 104 of these optical multiplexers 103, an optical multiplexer / demultiplexer 110, and an optical terminal 109 for inputting / outputting optical signals are sequentially connected in series.
[0024]
The interface device includes the optical terminal 109, the optical multiplexer / demultiplexer 110, the downstream input terminal 105, the optical demultiplexer 106 that demultiplexes the optical signal from the downstream input terminal 105, and the optical demultiplexer 106. A receiving unit configured by sequentially connecting a plurality of single-wavelength optical receivers corresponding to the plurality of wavelength outputs and a plurality of downstream output terminals corresponding to the single-wavelength optical receivers 107 in series; .
[0025]
Next, the operation will be described. When optical input signals having different wavelengths are input from the upstream input terminals 101, the single wavelength light source device 102 oscillates optical signals having different desired frequencies set in advance with amplitudes corresponding to the optical input signals. Further, a plurality of optical signals from each single-wavelength light source device 102 are combined by the optical multiplexer 103 to form one multi-wavelength optical signal and output to one upstream output terminal 104. Further, the multi-wavelength optical signal is output from the upstream output terminal 104 to the optical terminal 109 through the optical multiplexer / demultiplexer 110.
[0026]
On the other hand, the interface device receives one multi-wavelength optical signal supplied from the outside through the optical terminal 109, the optical multiplexer / demultiplexer 110, and the downstream input terminal 105. The optical demultiplexer 106 receives the multi-wavelength optical signal as a received optical signal and demultiplexes it into a plurality of received optical signals having different wavelengths. The single wavelength receiver 107 outputs the plurality of received optical signals through the plurality of downstream output terminals 108, respectively. As a result, it is possible to send and receive optical signals to and from the outside through a single optical terminal and optical fiber, and halve the amount of optical fiber used to connect the interface device to an external device. Optical wavelength division multiplexing transmission system and optical communication service Can be provided at low cost.
[0027]
By the way, a CWDM semiconductor laser without a temperature control mechanism used for the single wavelength light source 102 is manufactured with a certain wavelength variation with respect to an ITU-T grid wavelength of 20 nm as shown in FIG. Inspected and shipped. In FIG. 2, the wavelength variation is ± 2 nm. In an actual use state, it is necessary to pass a current of several tens to several hundreds of mA to the driver circuit and the semiconductor laser in order to incorporate these semiconductor lasers into the optical interface device together with the drive circuit and to input a signal into an operation state. .
[0028]
As a result, the element temperature of the semiconductor laser rises by about 10 to 15 ° C., and the oscillation wavelength of the semiconductor laser shifts to the longer wavelength side of 1 to 1.5 nm. Further, when the installation environment temperature of the apparatus rises to 50 ° C., the element temperature rises to about 65 ° C., so that it can be seen that the laser oscillation wavelength shifts to the maximum 6 nm long wavelength side in consideration of initial variations. Similarly, when the installation environment temperature of the optical interface device falls to about 0 ° C., the oscillation wavelength of the semiconductor laser shifts to the shortest wavelength side by a maximum of 3 nm.
[0029]
Therefore, as shown in FIG. 2, by shifting the center wavelength of the transmission band of the optical multiplexer 103 and the optical demultiplexer 106 to the long wavelength side by 1 nm and setting the transmission bandwidth to 9 nm or more, the wavelength due to the temperature change Can cover the shift. As a result, the interface function can be maintained even if the oscillation wavelength of the semiconductor laser is shifted by changing the environmental temperature of the place where the interface device is installed between 0 to 50 ° C. As a result, there is no need to prepare a temperature detection element or a temperature control (adjustment) element for the temperature control of the semiconductor laser in the conventional transmitter, and the transmission bandwidth is minimized while allowing temperature fluctuations. And an increase in the cost of the apparatus can be avoided.
[0030]
FIG. 3 is a block diagram showing an optical wavelength division multiplex transmission interface apparatus according to the second embodiment of the present invention. This interface device includes a plurality of upstream input terminals 301, a plurality of single wavelength light source devices 302 having wavelength characteristics corresponding to these, a plurality of optical multiplexer / demultiplexers 310, an optical multiplexer / demultiplexer 303, and an optical terminal 309. Are sequentially connected in series.
[0031]
The interface device includes an optical terminal 309, an optical multiplexer / demultiplexer 303, a plurality of optical multiplexer / demultiplexers 310 respectively corresponding to the plurality of wavelength outputs demultiplexed by the optical multiplexer / demultiplexer 303, and an optical multiplexer / demultiplexer 310. A receiving unit configured by sequentially connecting a single-wavelength light receiver 307 that receives an optical signal for each wavelength divided in step S1 and a downstream output terminal 308 corresponding to these single-wavelength light receivers 307 in series.
[0032]
In the interface device according to the second embodiment, first, when optical input signals having different wavelengths are input from the upstream input terminal 301, the single wavelength light source 302 receives optical signals having different predetermined frequencies set in advance. Oscillate with amplitudes corresponding to the optical input signals. The plurality of optical signals oscillated and output are output to the optical multiplexer / demultiplexer 303 through the optical multiplexer / demultiplexer 310, and the optical multiplexer / demultiplexer 303 multiplexes these optical signals. As a result, one multi-wavelength optical signal is obtained and output from one optical terminal 309 to the outside.
[0033]
On the other hand, when the interface device receives one multi-wavelength optical signal from the outside through one optical terminal 309, the interface device demultiplexes the received optical signal by the optical multiplexer / demultiplexer 303 to obtain a plurality of received optical signals having different wavelengths. . Further, the plurality of received optical signals having different wavelengths are received by the single wavelength receiver 307 through the optical multiplexer / demultiplexer 310, and the optical signals received by the single wavelength receiver 307 are output through the plurality of downstream output terminals 308, respectively.
[0034]
Therefore, in this second embodiment, the amount of optical fiber used to connect the single wavelength light source 302 and the single wavelength receiver 307 and the optical multiplexer / demultiplexer 303 via the optical multiplexer / demultiplexer 310 can be further reduced, and the apparatus and Communication service can be provided at a lower price. Further, by combining the optical multiplexer 103 and the optical demultiplexer 106 as shown in FIG. 1 into one optical multiplexer / demultiplexer 303, circuit arrangement, connection, and handling are facilitated, and cost can be reduced.
[0035]
FIG. 4 shows a schematic configuration of an optical wavelength division multiplex transmission interface apparatus according to the third embodiment of the present invention. This optical wavelength division multiplex transmission interface device includes a plurality of upstream input terminals 401, a plurality of single wavelength light source devices 402 having wavelength characteristics corresponding thereto, an optical multiplexer / demultiplexer 404, and an optical terminal 409 in series. It has a transmitter configured to be connected.
[0036]
The interface device includes the optical terminal 409, an optical multiplexer / demultiplexer 404, a plurality of single wavelength receivers 407 respectively corresponding to a plurality of wavelength outputs demultiplexed by the optical multiplexer / demultiplexer 403, and a single unit thereof. A receiving unit is configured by sequentially connecting a plurality of downstream output terminals 408 corresponding to the wavelength receiver 407 in series.
[0037]
In the interface device according to the third embodiment, first, when optical input signals having different wavelengths are input from the upstream input terminal 401, the single wavelength light source 402 receives optical signals having different predetermined frequencies set in advance. Oscillate with amplitudes corresponding to the optical input signals. The optical multiplexer / demultiplexer 404 receives the plurality of optical signals oscillated and output, and the optical multiplexer / demultiplexer 403 combines the optical outputs into one multi-wavelength optical signal, thereby combining one optical signal. Output to the outside via the terminal 409.
[0038]
On the other hand, when the interface device receives one multi-wavelength optical signal from the outside through one terminal 409, the optical multiplexer / demultiplexer 404 demultiplexes the received optical signal into a plurality of received optical signals having different wavelengths. The plurality of received optical signals having different wavelengths are input to the single wavelength receiver 407, and the optical signals obtained by the single wavelength receiver 407 are output through the plurality of downstream output terminals 408, respectively.
[0039]
By combining the optical multiplexer / demultiplexer 310 and the optical multiplexer / demultiplexer 303 as shown in FIG. 3 with one optical multiplexer / demultiplexer 404, circuit arrangement, connection, and handling can be facilitated, and cost can be reduced.
[0040]
In each of the above embodiments, unlike the conventional apparatus, the single wavelength light source devices 102, 302, 402, the optical multiplexer 103, the optical demultiplexer 106, and the optical demultiplexers 303, 404 are Peltier elements, thermistors, etc. It is composed of inexpensive parts without the temperature adjustment mechanism. For this reason, the interface device is not provided with a control circuit for temperature adjustment, and therefore, the power consumption is small and the interface device can be produced at low cost.
[0041]
In each of the above embodiments, an optical coupler or an optical circulator can be used as the optical combiner / splitter. In each of the above embodiments, the same effect can be obtained even if the single wavelength receiver is omitted and the wavelength-multiplexed optical signal is output as it is through the downstream output terminal.
[0042]
【The invention's effect】
As described above, according to the present invention, only one optical fiber for optical signal transmission connecting the optical wavelength division multiplexing transmission interface device and the external device is used by using the optical multiplexer / demultiplexer or the optical multiplexer / demultiplexer. As a result, the amount of optical fiber wiring can be greatly reduced, and therefore an optical wavelength division multiplexing transmission system and optical communication service can be provided at low cost. Furthermore, instead of controlling the temperature of the semiconductor laser, the wavelength oscillation shift is allowed within the minimum transmission bandwidth, so that a conventional temperature adjustment mechanism and circuit for temperature detection and temperature control can be provided. There is no need to provide a separate device, and the effect of reducing the size and cost of the apparatus can be obtained.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a first embodiment of an optical wavelength division multiplex transmission interface apparatus of the present invention. FIG. 2 is an operation explanatory diagram showing an operation of the embodiment of the present invention. FIG. 4 is a block diagram showing a second embodiment of the wavelength division multiplexing transmission interface apparatus. FIG. 4 is a block diagram showing a third embodiment of the optical wavelength division multiplexing interface apparatus of the present invention. Block diagram showing an example of a division multiplexing transmission interface device
102, 302, 402: single wavelength light source, 103: optical multiplexer, 106: optical demultiplexer, 107, 307, 407: single wavelength receiver, 110, 310: optical multiplexer / demultiplexer, 303, 404: optical multiplexing / demultiplexing vessel.

Claims

A plurality of single-wavelength light source devices each receiving a plurality of optical signals input from the outside and outputting optical signals of predetermined wavelengths having different intensities corresponding to the optical signals;
An optical multiplexer that combines a plurality of optical signals from the plurality of single-wavelength light source devices and outputs the optical signal as one multi-wavelength optical signal;
An optical demultiplexer that demultiplexes one multi-wavelength optical signal, in which a plurality of optical signals with different wavelengths are combined, for each wavelength and outputs the optical signals as a plurality of optical signals with different wavelengths;
Receiving a plurality of optical signals having different wavelengths from the optical demultiplexer, amplifying and shaping the waveform, and outputting a plurality of single wavelength receivers;
The output unit of the optical multiplexer, the input unit of the optical demultiplexer, and the outside, the optical signal from the output unit of the optical multiplexer is output to the outside, and the optical signal input from the outside is the input of the optical demultiplexer An optical combiner and shunt connected as input to the unit,
The optical wavelength division multiplexing, wherein a transmission band of the optical demultiplexer and the optical multiplexer is 9 nm or more, and a center wavelength of the transmission band is shifted to a wavelength longer by 1 nm than the ITU-T grid wavelength Transmission interface device.

A plurality of single-wavelength light source devices each receiving a plurality of optical signals input from the outside and outputting optical signals of predetermined wavelengths having different intensities corresponding to the optical signals;
An optical multiplexer that combines a plurality of optical signals from the plurality of single-wavelength light source devices and outputs the optical signal as one multi-wavelength optical signal;
An optical demultiplexer that demultiplexes one multi-wavelength optical signal, in which a plurality of optical signals with different wavelengths are combined, for each wavelength and outputs the optical signals as a plurality of optical signals with different wavelengths;
The output unit of the optical multiplexer, the input unit of the optical demultiplexer, and the outside, the optical signal from the output unit of the optical multiplexer is output to the outside, and the optical signal input from the outside is the input of the optical demultiplexer An optical combiner and shunt connected as input to the unit,
The optical wavelength division multiplexing, wherein a transmission band of the optical demultiplexer and the optical multiplexer is 9 nm or more, and a center wavelength of the transmission band is shifted to a wavelength longer by 1 nm than the ITU-T grid wavelength Transmission interface device.

A plurality of single-wavelength light source devices each receiving a plurality of optical signals input from the outside and outputting optical signals of predetermined wavelengths having different intensities corresponding to the optical signals;
A plurality of single-wavelength photoreceivers that respectively receive a plurality of optical signals having different wavelengths, amplify and shape the waveform, and output;
Multiple optical signals with different wavelengths input to multiple ports are combined and output to the outside as one multi-wavelength optical signal, and one multi-wavelength signal input from the outside is demultiplexed for each wavelength. An optical multiplexer / demultiplexer that outputs to a plurality of ports as a plurality of optical signals having different wavelengths,
The output unit of the plurality of single wavelength light source units, the input unit of the plurality of single wavelength receiver units, and the plurality of ports of the optical multiplexer / demultiplexer, the optical signal from the output unit of the single wavelength source unit is input to the optical multiplexer / demultiplexer A plurality of optical multiplexers / demultiplexers connected so that the optical signal output from the optical multiplexer / demultiplexer is input to the input unit of the single wavelength receiver,
The light transmission band demultiplexer is at 9nm or more, and the transmission band optical wavelength division multiplexing transmission interface device center wavelength is characterized by being displaced 1nm long wavelength side of ITU-T grid wavelength of .

A plurality of single-wavelength light source devices each receiving a plurality of optical signals input from the outside and outputting optical signals of predetermined wavelengths having different intensities corresponding to the optical signals;
Multiple optical signals with different wavelengths input to multiple ports are combined and output to the outside as one multi-wavelength optical signal, and one multi-wavelength signal input from the outside is demultiplexed for each wavelength. An optical multiplexer / demultiplexer that outputs to a plurality of ports as a plurality of optical signals having different wavelengths,
The optical signal from the output unit of the single wavelength light source is input to the optical multiplexer / demultiplexer, the output unit of the plurality of single wavelength light source units, the plurality of ports to the outside, and the plurality of ports of the optical multiplexer / demultiplexer. A plurality of optical combiners / dividers connected so that the optical signal output from the duplexer is input to the port to the outside,
The light transmission band demultiplexer is at 9nm or more, and the transmission band optical wavelength division multiplexing transmission interface device center wavelength is characterized by being displaced 1nm long wavelength side of ITU-T grid wavelength of .

5. The optical wavelength division multiplexing transmission interface apparatus according to claim 1, wherein the optical multiplexer / demultiplexer is an optical coupler.

5. The optical wavelength division multiplexing transmission interface apparatus according to claim 1, wherein the optical multiplexer / demultiplexer is an optical circulator.

A plurality of single-wavelength light source devices each receiving a plurality of optical signals input from the outside and outputting optical signals of predetermined wavelengths having different intensities corresponding to the optical signals;
A plurality of single-wavelength photoreceivers that respectively receive a plurality of optical signals having different wavelengths, amplify and shape the waveform, and output;
A plurality of optical signals from the plurality of single wavelength light source devices are combined and output to the outside as a single multi-wavelength optical signal, and one multi-wavelength signal input from the outside is demultiplexed for each wavelength. An optical multiplexer / demultiplexer that inputs to the plurality of single wavelength receivers as a plurality of different optical signals,
The light transmission band demultiplexer is at 9nm or more, and the transmission band optical wavelength division multiplexing transmission interface device center wavelength is characterized by being displaced 1nm long wavelength side of ITU-T grid wavelength of .

A plurality of single-wavelength light source devices each receiving a plurality of optical signals input from the outside and outputting optical signals of predetermined wavelengths having different intensities corresponding to the optical signals;
A plurality of optical signals from the plurality of single wavelength light source devices are combined and output to the outside as a single multi-wavelength optical signal, and one multi-wavelength signal input from the outside is demultiplexed for each wavelength. An optical multiplexer / demultiplexer that outputs to the outside as a plurality of different optical signals,
The light transmission band demultiplexer is at 9nm or more, and the transmission band optical wavelength division multiplexing transmission interface device center wavelength is characterized by being displaced 1nm long wavelength side of ITU-T grid wavelength of .