JP2002236271A - Optical time division multiplexer - Google Patents
Optical time division multiplexerInfo
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- JP2002236271A JP2002236271A JP2001031571A JP2001031571A JP2002236271A JP 2002236271 A JP2002236271 A JP 2002236271A JP 2001031571 A JP2001031571 A JP 2001031571A JP 2001031571 A JP2001031571 A JP 2001031571A JP 2002236271 A JP2002236271 A JP 2002236271A
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- optical
- channel
- signal
- multiplexer
- pulse train
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- Optical Modulation, Optical Deflection, Nonlinear Optics, Optical Demodulation, Optical Logic Elements (AREA)
- Semiconductor Lasers (AREA)
- Time-Division Multiplex Systems (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、複数の低速光パル
ス信号を時分割多重化して高速光パルス信号を生成する
光時分割多重装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical time division multiplexing apparatus for generating a high speed optical pulse signal by time division multiplexing a plurality of low speed optical pulse signals.
【０００２】[0002]
【従来の技術】図１０は、従来の光時分割多重装置の構
成例を示す（参考文献：G.E.Wickens,et al., "20Gbit/
s, 205km optical division multiplexed transmission
system",Electron. Lett., vol.27, no.11, pp.973-97
4, 1991)。2. Description of the Related Art FIG. 10 shows an example of the configuration of a conventional optical time division multiplexing device (reference: GE Wickens, et al., "20 Gbit / s").
s, 205km optical division multiplexed transmission
system ", Electron. Lett., vol.27, no.11, pp.973-97
4, 1991).
【０００３】図において、低速の光パルス列(a) は、光
分波器１１でＮ分波して光変調器１２−１〜１２−Ｎに
入力される。光変調器１２−１〜１２−Ｎに入力された
光パルス列(b) は、それぞれ変調されて低速の光信号列
(c) となり、光遅延器１３−１〜１３−Ｎでそれぞれ所
定の遅延が与えられる。光遅延器１３−１〜１３−Ｎか
ら出力される低速の光信号列(d) は光合波器１４で時分
割多重され、高速の多重光信号列(e) となる。In FIG. 1, a low-speed optical pulse train (a) is demultiplexed into N light by an optical demultiplexer 11 and input to optical modulators 12-1 to 12-N. The optical pulse trains (b) input to the optical modulators 12-1 to 12-N are respectively modulated and sent to a low-speed optical signal train.
(c), and a predetermined delay is given to each of the optical delay units 13-1 to 13-N. The low-speed optical signal sequence (d) output from the optical delay units 13-1 to 13-N is time-division multiplexed by the optical multiplexer 14, and becomes a high-speed multiplexed optical signal sequence (e).
【０００４】ここで、Ｎ＝４の場合において、低速の光
パルス列(a) から高速の多重光信号列(e) が生成される
過程を図１１に示す。高速の多重光信号列(e) の１タイ
ムスロット（１ビット当たりの時間）をＴとすると、低
速の光パルス列(a) のパルス間隔は４Ｔとなる。光変調
器１２−１〜１２−Ｎを駆動するデータ信号は、それぞ
れ“１０１”、“１１１”、“１０１”、“１１０”で
あり、それぞれ光パルス列(b) を変調して光信号列(c)
を生成する。光遅延器１３−１〜１３−Ｎでは、各チャ
ネルの光信号列(c) にそれぞれ０、Ｔ、２Ｔ、３Ｔの遅
延を与えて光信号列(d) とする。この光信号列(d) を時
分割多重化することにより、パルス間隔Ｔで“１１１１
０１０１１１１０”の高速の多重光信号列(e) が生成さ
れる。FIG. 11 shows a process of generating a high-speed multiplexed optical signal train (e) from a low-speed optical pulse train (a) when N = 4. Assuming that one time slot (time per bit) of the high-speed multiplexed optical signal train (e) is T, the pulse interval of the low-speed optical pulse train (a) is 4T. Data signals for driving the optical modulators 12-1 to 12-N are "101", "111", "101", and "110", respectively. c)
Generate In the optical delay units 13-1 to 13-N, the optical signal sequence (c) of each channel is delayed by 0, T, 2T, and 3T, respectively, to obtain an optical signal sequence (d). This optical signal train (d) is time-division multiplexed to obtain "1111" at pulse intervals T.
A high-speed multiplexed optical signal sequence (e) of "0101110" is generated.
【０００５】ところで、図１０に示す従来の光時分割多
重装置では、各チャネルの光路長は数ｍ以上になるの
で、環境温度などの変化によって遅延時間が大きく変動
することがある。光遅延器１３−１〜１３−Ｎの遅延時
間差がＴで安定していれば、図１２(1) に示すように時
分割多重化後のパルス間隔は一定になる。しかし、各チ
ャネルの遅延時間が変動すると、図１２(2) に示すよう
に光パルス信号が重なったり、図１２(3) に示すように
光パルス信号の順番が入れ替わる事態となる。In the conventional optical time division multiplexing apparatus shown in FIG. 10, since the optical path length of each channel is several meters or more, the delay time may fluctuate greatly due to a change in environmental temperature or the like. If the delay time difference between the optical delay units 13-1 to 13-N is stable at T, the pulse interval after time division multiplexing becomes constant as shown in FIG. However, if the delay time of each channel fluctuates, the optical pulse signals may overlap as shown in FIG. 12 (2) or the order of the optical pulse signals may be changed as shown in FIG. 12 (3).
【０００６】そのため、時分割多重化後の光信号のタイ
ムスロットＴが小さくなるにつれて、遅延時間の変動に
対する制限が厳しくなる。ところが、図１０の装置に用
いられる光遅延器は各チャネルの光路長が数ｍ以上にな
るため、光遅延量の厳密な調整が難しく、かつ温度変化
などによる変動が大きくなる問題が避けられなかった。Therefore, as the time slot T of the optical signal after the time division multiplexing becomes smaller, the restriction on the fluctuation of the delay time becomes more severe. However, in the optical delay device used in the apparatus of FIG. 10, since the optical path length of each channel is several meters or more, it is difficult to strictly adjust the optical delay amount, and the problem that the fluctuation due to a temperature change or the like becomes large is inevitable. Was.
【０００７】この問題を解決する方法として、光時分割
多重装置を図１３に示すように１つの基板上に集積化す
る構成が考えられている。すなわち、基板１５上にＮチ
ャネルの光導波路１６−１〜１６−Ｎを形成し、その基
板１５上に光分波器１１、光変調器１２−１〜１２−
Ｎ、光合波器１４を集積化し、光分波器から光合波器ま
での光導波路長の違いでＮチャネルにそれぞれ異なる遅
延を与える構成である（参考文献：F.Zamkotsian, et a
l.,"Generation and coding of a 100Gbit/s signal by
an InP-based optical multiplexer integrated with
modulators", Electron. Lett., vol.31, no.7, pp.578
-579, 1995) 。As a method for solving this problem, a configuration in which an optical time division multiplexing device is integrated on one substrate as shown in FIG. 13 has been considered. That is, N-channel optical waveguides 16-1 to 16-N are formed on the substrate 15, and the optical demultiplexer 11 and the optical modulators 12-1 to 12- are formed on the substrate 15.
N, the optical multiplexer 14 is integrated, and different delays are given to the N channels depending on the difference in the optical waveguide length from the optical demultiplexer to the optical multiplexer (reference: F. Zamkotsian, et a).
l., "Generation and coding of a 100Gbit / s signal by
an InP-based optical multiplexer integrated with
modulators ", Electron. Lett., vol. 31, no. 7, pp. 578
-579, 1995).
【０００８】このような構成では、光導波路長を厳密に
設定することが可能であり、さらに基板上に集積化され
ているので温度制御も容易であり、各チャネルの遅延時
間の絶対的なずれや時間変動を十分に抑えることができ
る。例えば、光導波路長は10ｃｍ程度であるので、単位
長さ当たりの遅延時間の温度係数が図１４に示した光フ
ァイバの値と同じと仮定すると、20℃の温度変化でも0.
06ｐｓ程度しか遅延時間の変動はない。In such a configuration, the length of the optical waveguide can be strictly set, and since the optical waveguide is integrated on the substrate, temperature control is easy, and the absolute shift of the delay time of each channel is made. And time fluctuation can be sufficiently suppressed. For example, since the optical waveguide length is about 10 cm, assuming that the temperature coefficient of the delay time per unit length is the same as the value of the optical fiber shown in FIG.
The delay time varies only by about 06 ps.
【０００９】[0009]
【発明が解決しようとする課題】ところが、図１３に示
す従来の光時分割多重装置は、光変調器１２として電界
吸収型光変調器やＬiＮbＯ3 光変調器を用い、集積化し
た基板上で電気信号による変調を行う構成であるので、
ビットレートが大きくなると高周波のチャネル間クロス
トークが問題になる。また、高周波電気配線の損失が問
題になる。さらに、チャネル数Ｎが３以上になると高周
波電気配線と光導波路の多層配線が必要になり、構造が
複雑になる問題もある。However, the conventional optical time-division multiplexing device shown in FIG. 13 uses an electro-absorption type optical modulator or a LiNbO 3 optical modulator as the optical modulator 12 and uses an integrated substrate. Because it is a configuration that performs modulation by electric signals,
As the bit rate increases, crosstalk between high-frequency channels becomes a problem. Further, the loss of the high-frequency electric wiring becomes a problem. Further, when the number N of channels is 3 or more, a multilayer wiring of high-frequency electric wiring and optical waveguides is required, and there is a problem that the structure becomes complicated.
【００１０】この問題を解決する方法として、光時分割
多重装置を構成する各部を基板上に集積化する構成にお
いて、図１５に示すように光変調信号によって変調動作
を行う光変調器（半導体光増幅器、電界吸収型光変調
器）を用い、基板上で高周波電気配線を不要とする構成
が考えられている。すなわち、光変調器１７−１〜１７
−Ｎは、光合波器１８−１〜１８−Ｎを介して光パルス
列(b) と光変調信号(f)を入力し、半導体光増幅器の四
光波混合または相互利得変調、あるいは電界吸収型光変
調器の相互吸収変調を用い、光変調信号によって変調動
作を行う（参考文献：特開平１１−７２７５７号公
報）。As a method for solving this problem, an optical modulator (semiconductor optical modulator) that performs a modulation operation with an optical modulation signal as shown in FIG. A configuration has been considered in which an amplifier and an electro-absorption optical modulator) are used and high-frequency electrical wiring is not required on a substrate. That is, the optical modulators 17-1 to 17-17
-N inputs the optical pulse train (b) and the optical modulation signal (f) via the optical multiplexers 18-1 to 18-N, and performs four-wave mixing or mutual gain modulation of a semiconductor optical amplifier, or electro-absorption type light. A modulation operation is performed by an optical modulation signal using the mutual absorption modulation of the modulator (reference: Japanese Patent Application Laid-Open No. H11-72757).
【００１１】しかし、半導体光増幅器では、四光波混合
の発生効率や相互利得変調時のパタン効果による消光比
劣化などの問題があり、電界吸収型光変調器では損失の
問題があり、それぞれの素子長や損失特性の最適化条件
が厳しかった。However, the semiconductor optical amplifier has problems such as the generation efficiency of four-wave mixing and the deterioration of the extinction ratio due to the pattern effect at the time of mutual gain modulation, and the electroabsorption optical modulator has the problem of loss. Optimization conditions for length and loss characteristics were severe.
【００１２】本発明は、光時分割多重装置を構成する各
部を基板上に集積化する構成において、高周波電気配線
を不要とし、かつ多重光信号の消光比劣化やパタン効果
が小さく、変換効率が大きい光時分割多重装置を提供す
ることを目的とする。According to the present invention, in a configuration in which the components constituting the optical time-division multiplexing device are integrated on a substrate, high-frequency electrical wiring is not required, the extinction ratio deterioration of the multiplexed optical signal and the pattern effect are small, and the conversion efficiency is reduced. It is an object to provide a large optical time division multiplexing device.
【００１３】[0013]
【課題を解決するための手段】本発明の光時分割多重装
置は、繰り返し周波数ｆ0 の光パルス列を入力し、Ｎチ
ャネル（Ｎは２以上の整数）に分波するＮチャネル光分
波器と、光パルス列に同期したＮチャネルの光変調信号
を入力し、それぞれ対応するチャネルの光パルス列の強
度または位相をそれぞれ変調してビットレートｆ0 の光
信号列に変換するＮ個の光変調器と、各光変調器から出
力された光信号列を合波するＮチャネル光合波器と、Ｎ
チャネル光分波器からＮチャネル光合波器に至るＮチャ
ネルの経路を異なる長さで結合し、各チャネルの光信号
列にそれぞれ異なる遅延を与えるＮ本の光導波路と、Ｎ
チャネル光分波器、Ｎ個の光変調器、Ｎチャネル光合波
器、Ｎ本の光導波路を集積化する基板とを備え、Ｎチャ
ネル光合波器からビットレートＮ・ｆ0 の多重光信号列
を出力する光時分割多重装置において、各光変調器は、
入力する光パルス列を２分岐する光分波器と、その２経
路に挿入される２つの半導体光増幅器と、各半導体光増
幅器の出力を合波する光合波器とからなる対称マッハツ
ェンダ型干渉部を構成し、その一方の経路に挿入した光
変調信号用光合波器を介して、光変調信号を一方の半導
体光増幅器に入力し、２つの半導体光増幅器から光変調
信号によって位相変調を受けた光パルス列と位相変調を
受けない光パルス列を出力し、光合波器から光変調信号
に対応する強度変調された光信号列を出力する構成であ
る。Optical time division multiplexing apparatus of the present invention, in order to solve the problems], enter the optical pulse train of repetition frequency f 0, N-channel (N is an integer of 2 or more) N-channel optical demultiplexer which demultiplexes the And N optical modulators that input an N-channel optical modulation signal synchronized with the optical pulse train, modulate the intensity or phase of the optical pulse train of the corresponding channel, respectively, and convert it to an optical signal train of a bit rate f 0 . An N-channel optical multiplexer for multiplexing an optical signal train output from each optical modulator;
N optical waveguides for coupling the N-channel paths from the channel optical demultiplexer to the N-channel optical multiplexer with different lengths and providing different delays to the optical signal trains of the respective channels;
A channel optical demultiplexer, N optical modulators, an N-channel optical multiplexer, and a substrate on which N optical waveguides are integrated, and a multiplexed optical signal train having a bit rate of N · f 0 from the N-channel optical multiplexer. In an optical time division multiplexing device that outputs
A symmetric Mach-Zehnder interferometer comprising an optical demultiplexer that splits an input optical pulse train into two, two semiconductor optical amplifiers inserted into the two paths, and an optical multiplexer that multiplexes the output of each semiconductor optical amplifier. The optical modulation signal is input to one of the semiconductor optical amplifiers via the optical modulator for optical modulation signal inserted into one of the paths, and the light is subjected to phase modulation by the optical modulation signal from the two semiconductor optical amplifiers. In this configuration, a pulse train and an optical pulse train that is not subjected to phase modulation are output, and an intensity-modulated optical signal train corresponding to the optical modulation signal is output from the optical multiplexer.
【００１４】また、本発明の光時分割多重装置は、Ｎチ
ャネルの光変調信号をそれぞれ２分岐するＮ個の光変調
信号用光分波器と、それぞれ２分岐された２つの光変調
信号との間に所定の位相差（遅延）を与えて各光変調器
に入力する光導波路とを基板上に集積化し、上記光変調
器に代わる各光変調器は、入力する光パルス列を２分岐
する光分波器と、その２経路に挿入される２つの半導体
光増幅器と、各半導体光増幅器の出力を合波する光合波
器とからなる対称マッハツェンダ型干渉部を構成し、各
経路にそれぞれ挿入された光変調信号用光合波器を介し
て、所定の位相差を有する２つの光変調信号を２つの半
導体光増幅器にそれぞれ入力し、２つの半導体光増幅器
から光変調信号によって位相変調を受けた光パルス列を
出力し、光合波器から光変調信号に対応する強度変調さ
れた光信号列を出力する構成としてもよい。Further, the optical time division multiplexing device of the present invention comprises N optical modulation signal optical demultiplexers for branching each of the N-channel optical modulation signals into two, and two optical modulation signals for each of two branches. A predetermined phase difference (delay) is given between the optical modulators and an optical waveguide to be input to each optical modulator is integrated on a substrate, and each optical modulator instead of the above-mentioned optical modulator branches an input optical pulse train into two. A symmetric Mach-Zehnder type interference unit composed of an optical demultiplexer, two semiconductor optical amplifiers inserted in the two paths, and an optical multiplexer for multiplexing the outputs of the semiconductor optical amplifiers is inserted into each path. The two optical modulation signals having a predetermined phase difference are respectively input to the two semiconductor optical amplifiers through the optical multiplexer for optical modulation signals, and subjected to phase modulation by the optical modulation signals from the two semiconductor optical amplifiers. Outputs an optical pulse train and generates an optical multiplexer May output the intensity-modulated optical signal train corresponding to Hikari Luo modulation signal.
【００１５】また、各光変調器は、対称マッハツェンダ
型干渉部の２経路部分で反射する構成として光分波器と
光合波器を共用する構成とし、Ｎチャネル光分波器とＮ
チャネル光合波器を共用する構成としてもよい。Each of the optical modulators is configured to share an optical demultiplexer and an optical multiplexer as a configuration that reflects light at two paths of a symmetric Mach-Zehnder interference unit.
The configuration may be such that the channel optical multiplexer is shared.
【００１６】また、光変調信号または光パルス列にＣＷ
光を合波して半導体光増幅器に入力するＣＷ光用光合波
器を備えてもよい。また、基板上で、光変調器の前段ま
たは後段に光増幅器を集積化する構成としてもよい。ま
た、光導波路を形成する基板として半導体基板または石
英系基板またはセラミック系基板を用いる構成としても
よい。The CW is added to the optical modulation signal or the optical pulse train.
An optical multiplexer for CW light that multiplexes light and inputs the multiplexed light to the semiconductor optical amplifier may be provided. Further, the optical amplifier may be integrated on the substrate either before or after the optical modulator. Further, a semiconductor substrate, a quartz substrate, or a ceramic substrate may be used as a substrate on which an optical waveguide is formed.
【００１７】[0017]
【発明の実施の形態】（第１の実施形態）図１は、本発
明の光時分割多重装置の第１の実施形態を示す。ここで
は、光時分割多重数Ｎ＝８の場合の構成例を示す。(First Embodiment) FIG. 1 shows a first embodiment of an optical time division multiplexing apparatus according to the present invention. Here, a configuration example when the number of optical time division multiplexing N = 8 is shown.
【００１８】図において、図外の光パルス列発生源で発
生させた繰り返し周波数ｆ0 の光パルス列（被変調光）
は、基板１５に形成された光分波器１１で８チャネルに
分波され、基板１５上の８本の光導波路１６−１〜１６
−８を介してそれぞれ基板１５上の光変調器２０−１〜
２０−８に入力される。一方、繰り返し周波数ｆ0 の光
パルス列に同期した８チャネルの光変調信号は、基板１
５のポートch１〜ch８から基板１５上の８本の光導波路
１９−１〜１９−８を介して、それぞれ光変調器２０−
１〜２０−８に入力される。光変調器２０−１〜２０−
８は、光パルス列をそれぞれ対応する光変調信号で変調
し、ビットレートｆ0 の８チャネルの光信号列を出力す
る。８チャネルの光信号列は、基板１５上の光導波路１
６−１〜１６−８を介して基板１５上の光合波器１４に
入力され、時分割多重されてビットレート８ｆ0 の多重
光信号列として出力される。基板１５としては石英系基
板または半導体系基板またはセラミック系基板を用い、
その上に石英系光導波路または半導体光導波路またはセ
ラミック系光導波路を形成する。In the figure, an optical pulse train (modulated light) having a repetition frequency f 0 generated by an optical pulse train generating source (not shown)
Are demultiplexed into eight channels by the optical demultiplexer 11 formed on the substrate 15, and the eight optical waveguides 16-1 to 16
-8, the optical modulators 20-1 to 20-1 on the substrate 15 respectively.
20-8. On the other hand, the optical modulation signal of eight channels synchronized with the optical pulse train of the repetition frequency f 0
The optical modulators 20-1 through 19-8 through the eight optical waveguides 19-1 through 19-8 on the substrate 15 respectively.
1 to 20-8. Optical modulators 20-1 to 20-
8 modulates the optical pulse train at the corresponding modulated optical signal, and outputs the optical signal train of 8 channel bit rate f 0. The optical signal train of eight channels is transmitted through the optical waveguide 1 on the substrate 15.
6-1～16-8 inputted to the optical multiplexer 14 on the substrate 15 via a output are time division multiplexed as multiplexed optical signal train of bit rate 8f 0. A quartz substrate, a semiconductor substrate, or a ceramic substrate is used as the substrate 15.
A quartz optical waveguide, a semiconductor optical waveguide, or a ceramic optical waveguide is formed thereon.
【００１９】なお、光分波器１１と光合波器１４との間
の光導波路１６−１〜１６−８の長さは、８チャネルの
光信号列にそれぞれ異なる遅延を与え、光合波器１４で
時分割多重したときにビットレート８ｆ0 の多重光信号
列になるように設定される。The lengths of the optical waveguides 16-1 to 16-8 between the optical demultiplexer 11 and the optical multiplexer 14 give different delays to the eight-channel optical signal trains. Are set so as to become a multiplexed optical signal train having a bit rate of 8f 0 when time-division multiplexing is performed.
【００２０】本実施形態の特徴は光変調器２０−１〜２
０−８の構成にある。光変調器２０−１は、光導波路１
６−１から入力される光パルス列を２分岐する光分波器
２１と、２分岐された２経路に挿入される２つの半導体
光増幅器２２−１，２２−２と、各半導体光増幅器の出
力を合波してそれぞれ光導波路１６−１に出力する光合
波器２３と、光導波路１９−１から入力される光変調信
号と光分波器２１で２分岐された一方の光パルス列とを
合波して一方の半導体光増幅器２２−１に入力する光合
波器２４により構成される。光変調器２０−２〜２０−
８も同様である。The feature of this embodiment is that the optical modulators 20-1 and 20-2 are used.
0-8. The optical modulator 20-1 includes the optical waveguide 1
An optical demultiplexer 21 for branching an optical pulse train input from 6-1 into two, two semiconductor optical amplifiers 22-1 and 22-2 inserted into two branched paths, and outputs of the respective semiconductor optical amplifiers And an optical multiplexer 23 that multiplexes the optical pulse signals and outputs the optical modulation signals to the optical waveguide 16-1 and the optical modulation signal input from the optical waveguide 19-1 and one of the optical pulse trains branched by the optical demultiplexer 21. It is composed of an optical multiplexer 24 that oscillates and inputs the signal to one semiconductor optical amplifier 22-1. Optical modulators 20-2 to 20-
8 is also the same.
【００２１】ここで、光分波器２１で２分岐される光パ
ルス列を光パルス列Ａ，光パルス列Ｂとし、光パルス列
Ａが光変調信号と光合波器２４で合波されて半導体光増
幅器２２−１に入力されるものとする。このとき光パル
ス列Ａは、半導体光増幅器２２−１における非線形光学
効果（相互位相変調効果）に基づき光変調信号によって
そのデータパタンに依存した位相変調を受ける。一方、
光パルス列Ｂは、光変調信号と合波されることなく半導
体光増幅器２２−２に入力され、そのまま出力される。
半導体光増幅器２２−１，２２−２の出力光は光合波器
２３で合波されるが、位相変調を受けた光パルス列Ａと
位相変調を受けない光パルス列Ｂは光変調信号に応じた
位相差があるので、合波後の光パルス列は光変調信号と
同じデータ列の強度変調光信号（光信号列）となる。こ
のとき、光パルス列Ａと光パルス列Ｂの位相差が（２ｎ
＋１）π（ｎは正の整数）のときに、強度変調度は最大
となる。Here, the optical pulse train branched into two by the optical demultiplexer 21 is referred to as an optical pulse train A and an optical pulse train B. The optical pulse train A is multiplexed with the optical modulation signal by the optical multiplexer 24 and the semiconductor optical amplifier 22- It is assumed that it is input to 1. At this time, the optical pulse train A is subjected to phase modulation depending on its data pattern by an optical modulation signal based on the nonlinear optical effect (mutual phase modulation effect) in the semiconductor optical amplifier 22-1. on the other hand,
The optical pulse train B is input to the semiconductor optical amplifier 22-2 without being combined with the optical modulation signal, and is output as it is.
The output lights of the semiconductor optical amplifiers 22-1 and 22-2 are multiplexed by the optical multiplexer 23, and the optical pulse train A that has undergone phase modulation and the optical pulse train B that has not undergone phase modulation have a position corresponding to the optical modulation signal. Since there is a phase difference, the combined optical pulse train becomes an intensity-modulated optical signal (optical signal train) having the same data sequence as the optical modulation signal. At this time, the phase difference between the optical pulse train A and the optical pulse train B is (2n
+1) When n is a positive integer, the degree of intensity modulation becomes maximum.
【００２２】（第２の実施形態）図２は、本発明の光時
分割多重装置の第２の実施形態を示す。ここでは、光時
分割多重数Ｎ＝８の場合の構成例を示す。(Second Embodiment) FIG. 2 shows a second embodiment of the optical time division multiplexer according to the present invention. Here, a configuration example when the number of optical time division multiplexing N = 8 is shown.
【００２３】図において、図外の光パルス列発生源で発
生させた繰り返し周波数ｆ0 の光パルス列（被変調光）
は、基板１５に形成された光分波器１１で８チャネルに
分波され、基板１５上の８本の光導波路１６−１〜１６
−８を介してそれぞれ基板１５上の光変調器３０−１〜
３０−８に入力される。一方、繰り返し周波数ｆ0 の光
パルス列に同期した８チャネルの光変調信号は、基板１
５のポートch１〜ch８から基板１５上の８本の光導波路
１９−１〜１９−８を介して、それぞれ光変調器３０−
１〜３０−８に入力される。光変調器３０−１〜３０−
８は、光パルス列をそれぞれ対応する光変調信号で変調
し、ビットレートｆ0 の８チャネルの光信号列を出力す
る。８チャネルの光信号列は、基板１５上の光導波路１
６−１〜１６−８を介して基板１５上の光合波器１４に
入力され、時分割多重されてビットレート８ｆ0 の多重
光信号列として出力される。In the figure, an optical pulse train (modulated light) having a repetition frequency f 0 generated by an optical pulse train generating source (not shown)
Are demultiplexed into eight channels by the optical demultiplexer 11 formed on the substrate 15, and the eight optical waveguides 16-1 to 16
-8, the optical modulators 30-1 to 30-1 on the substrate 15 respectively.
30-8. On the other hand, the optical modulation signal of eight channels synchronized with the optical pulse train of the repetition frequency f 0
The optical modulators 30- through 8 optical waveguides 19-1 through 19-8 on the substrate 15 respectively from the ports ch1 through ch8 of the fifth circuit.
1 to 30-8. Optical modulators 30-1 to 30-
8 modulates the optical pulse train at the corresponding modulated optical signal, and outputs the optical signal train of 8 channel bit rate f 0. The optical signal train of eight channels is transmitted through the optical waveguide 1 on the substrate 15.
6-1～16-8 inputted to the optical multiplexer 14 on the substrate 15 via a output are time division multiplexed as multiplexed optical signal train of bit rate 8f 0.
【００２４】なお、光分波器１１と光合波器１４との間
の光導波路１６−１〜１６−８の長さは、８チャネルの
光信号列にそれぞれ異なる遅延を与え、光合波器１４で
時分割多重したときにビットレート８ｆ0 の多重光信号
列になるように設定される。The lengths of the optical waveguides 16-1 to 16-8 between the optical demultiplexer 11 and the optical multiplexer 14 give different delays to the eight-channel optical signal trains. Are set so as to become a multiplexed optical signal train having a bit rate of 8f 0 when time-division multiplexing is performed.
【００２５】本実施形態の特徴は光変調器３０−１〜３
０−８の構成にある。光変調器３０−１は、光導波路１
６−１から入力される光パルス列を２分岐する光分波器
２１と、２分岐された２経路に挿入される２つの半導体
光増幅器２２−１，２２−２と、各半導体光増幅器の出
力を合波してそれぞれ光導波路１６−１に出力する光合
波器２３と、光導波路１９−１から入力される光変調信
号を２分岐する光分波器２５と、２分岐された各光変調
信号間に所定の位相差Δτを与える光導波路２６−１，
２６−２と、光導波路２６−１からの光変調信号と光分
波器２１で２分岐された一方の光パルス列とを合波して
一方の半導体光増幅器２２−１に入力する光合波器２４
−１と、光導波路２６−２からの光変調信号と光分波器
２１で２分岐された他方の光パルス列とを合波して他方
の半導体光増幅器２２−２に入力する光合波器２４−２
により構成される。光変調器３０−２〜３０−８も同様
である。This embodiment is characterized in that the optical modulators 30-1 to 30-3 are used.
0-8. The optical modulator 30-1 includes the optical waveguide 1
An optical demultiplexer 21 for branching an optical pulse train input from 6-1 into two, two semiconductor optical amplifiers 22-1 and 22-2 inserted into two branched paths, and outputs of the respective semiconductor optical amplifiers The optical multiplexer 23 multiplexes the optical modulation signals and outputs the optical modulation signals to the optical waveguide 16-1; the optical demultiplexer 25 divides the optical modulation signal input from the optical waveguide 19-1 into two branches; An optical waveguide 26-1, which gives a predetermined phase difference Δτ between signals,
26-2, an optical modulator that multiplexes the optical modulation signal from the optical waveguide 26-1 and one of the optical pulse trains branched by the optical demultiplexer 21 and inputs the multiplexed signal to one of the semiconductor optical amplifiers 22-1. 24
-1 and the optical modulation signal from the optical waveguide 26-2 and the other optical pulse train branched into two by the optical demultiplexer 21 to be multiplexed and input to the other semiconductor optical amplifier 22-2. -2
It consists of. The same applies to the optical modulators 30-2 to 30-8.
【００２６】なお、ここでは、光分波器２５および光導
波路２６−１，２６−２を光変調器３０の一部として説
明したが、光変調器３０の外にあるものとして扱っても
よい。Although the optical demultiplexer 25 and the optical waveguides 26-1 and 26-2 have been described as a part of the optical modulator 30, they may be treated as being outside the optical modulator 30. .
【００２７】ここで、光分波器２１で２分岐される光パ
ルス列を光パルス列Ａ，光パルス列Ｂとし、光分波器２
５で２分岐される光変調信号を光変調信号Ａ，光変調信
号Ｂとし、光パルス列Ａが光変調信号Ａと光合波器２４
−１で合波されて半導体光増幅器２２−１に入力され、
光パルス列Ｂが光変調信号Ｂと光合波器２４−２で合波
されて半導体光増幅器２２−２に入力されるものとす
る。このとき光パルス列Ａは、半導体光増幅器２２−１
における非線形光学効果（相互位相変調効果）に基づき
光変調信号Ａによってそのデータパタンに依存した位相
変調を受ける。一方、光パルス列Ｂは、半導体光増幅器
２２−２における非線形光学効果（相互位相変調効果）
に基づき光変調信号Ｂによってそのデータパタンに依存
した位相変調を受ける。Here, the optical pulse train branched into two by the optical demultiplexer 21 is referred to as an optical pulse train A and an optical pulse train B.
The optical modulation signal branched into two at 5 is an optical modulation signal A and an optical modulation signal B, and the optical pulse train A is composed of the optical modulation signal A and the optical multiplexer 24.
-1 and input to the semiconductor optical amplifier 22-1.
It is assumed that the optical pulse train B is multiplexed with the optical modulation signal B by the optical multiplexer 24-2 and input to the semiconductor optical amplifier 22-2. At this time, the optical pulse train A is a semiconductor optical amplifier 22-1.
Is subjected to phase modulation depending on the data pattern by the optical modulation signal A based on the nonlinear optical effect (cross-phase modulation effect) in. On the other hand, the optical pulse train B has a nonlinear optical effect (cross-phase modulation effect) in the semiconductor optical amplifier 22-2.
Is subjected to phase modulation depending on the data pattern by the optical modulation signal B.
【００２８】ただし、両者の位相変調のタイミングは、
光導波路２６−１、２６−２の光路長差によって生じる
Δτのずれがある。これにより、半導体光増幅器２２−
１，２２−２の出力光が光合波器２３で合波されるとき
に、データパタンに依存した位相変調を受けた光パルス
列Ａと光パルス列Ｂの位相差により、合波後の光パルス
列は光変調信号と同じデータ列の強度変調光信号（光信
号列）となる。このとき、光パルス列Ａと光パルス列Ｂ
の位相差が（２ｎ＋１）π（ｎは正の整数）のときに、
強度変調度は最大となる。しかも、位相変調のタイミン
グのずれΔτは、強度変調光信号の光パルスの立ち下が
り時間を早める効果がある。However, the timing of both phase modulations is
There is a shift of Δτ caused by the optical path length difference between the optical waveguides 26-1 and 26-2. Thereby, the semiconductor optical amplifier 22-
When the output lights 1, 22-2 are multiplexed by the optical multiplexer 23, the multiplexed optical pulse train is formed by the phase difference between the optical pulse train A and the optical pulse train B that have undergone phase modulation depending on the data pattern. It becomes an intensity-modulated optical signal (optical signal sequence) of the same data sequence as the optical modulation signal. At this time, the optical pulse train A and the optical pulse train B
Is (2n + 1) π (n is a positive integer),
The intensity modulation degree becomes maximum. In addition, the shift Δτ of the phase modulation timing has the effect of shortening the fall time of the optical pulse of the intensity-modulated optical signal.
【００２９】図３(1) は第１の実施形態の光変調器２０
の動作例を示し、図３(2) は第２の実施形態の光変調器
３０の動作例を示す。ここでは、半導体光増幅器２２−
１，２２−２から出力される位相変調された光パルス列
Ａ，Ｂと、光合波器２３から出力される強度変調光信号
を示す。FIG. 3A shows an optical modulator 20 according to the first embodiment.
3 (2) shows an operation example of the optical modulator 30 of the second embodiment. Here, the semiconductor optical amplifier 22-
2 shows phase-modulated optical pulse trains A and B output from 1, 22-2 and an intensity-modulated optical signal output from the optical multiplexer 23.
【００３０】図３(1),(2) 左は、半導体光増幅器２２−
１，２２−２において光パルス列Ａ，Ｂが受ける位相変
調度の時間変化を示しており、半導体光増幅器内のキャ
リア時間変動に依存している。図３(1),(2) 右は、光合
波器２３後に得られる強度変調パタンを表している。第
１の実施形態の光変調器２０では、光変調信号のデータ
パタンに依存する位相変調がそのまま強度変調に現れ
る。第２の実施形態の光変調器３０では、光変調信号の
データパタンに依存する位相変調を受けた光パルス列
Ａ，Ｂに位相差Δτがあるので、強度変調光信号のパル
ス波形はΔτで急速に立ち下がる。すなわち、強度変調
光信号のパルス幅は、半導体光増幅器２２−１，２２−
２に入力する光変調信号Ａ，Ｂの遅延差Δτ（光導波路
２６−１，２６−２の光路長差）で設定することができ
る。3 (1) and 3 (2) The left is the semiconductor optical amplifier 22-.
In FIGS. 1 and 2-2, the temporal changes in the degree of phase modulation applied to the optical pulse trains A and B are shown, which depend on the carrier time fluctuation in the semiconductor optical amplifier. 3 (1) and 3 (2) show the intensity modulation patterns obtained after the optical multiplexer 23. In the optical modulator 20 according to the first embodiment, the phase modulation depending on the data pattern of the optical modulation signal directly appears in the intensity modulation. In the optical modulator 30 according to the second embodiment, since the optical pulse trains A and B that have undergone phase modulation depending on the data pattern of the optical modulation signal have a phase difference Δτ, the pulse waveform of the intensity-modulated optical signal has a rapid Δτ. Fall to. That is, the pulse width of the intensity-modulated optical signal is determined by the semiconductor optical amplifiers 22-1, 22-
2 can be set by the delay difference Δτ (the optical path length difference between the optical waveguides 26-1 and 26-2) between the optical modulation signals A and B input to the optical waveguide 2.
【００３１】（第３の実施形態）図４は、本発明の光時
分割多重装置の第３の実施形態を示す。ここでは、光時
分割多重数Ｎ＝８の場合の構成例を示す。(Third Embodiment) FIG. 4 shows a third embodiment of the optical time division multiplexing device of the present invention. Here, a configuration example when the number of optical time division multiplexing N = 8 is shown.
【００３２】本実施形態は、第１の実施形態の光変調器
２０−１〜２０−８の半導体光増幅器２２−１，２２−
２を反射型にしたことを特徴とする（参考文献：R.Sato
他、10Gbit/s SOA-PLCハイブリッド集積波長変換モジュ
ール、1999年電子情報通信学会秋季全国大会）。これに
より、光分波器２１が第１の実施形態における光分波器
２１および光合波器２３として機能し、光分波器１１が
第１の実施形態における光分波器１１および光合波器１
４として機能する折り返し型の構成となる。また、光サ
ーキュレータ２７を用い、光分波器１１に入力する光パ
ルス列と、光分波器１１から逆方向に出力される多重光
信号列を分離する。光変調器２０−１〜２０−８におけ
る変調動作は第１の実施形態と同様である。In the present embodiment, the semiconductor optical amplifiers 22-1, 22-22 of the optical modulators 20-1 to 20-8 of the first embodiment are used.
2 is a reflection type (Reference: R. Sato
Others, 10Gbit / s SOA-PLC hybrid integrated wavelength conversion module, IEICE Autumn National Convention 1999). Thereby, the optical demultiplexer 21 functions as the optical demultiplexer 21 and the optical multiplexer 23 in the first embodiment, and the optical demultiplexer 11 functions as the optical demultiplexer 11 and the optical multiplexer in the first embodiment. 1
This is a folded-type configuration that functions as 4. Further, the optical circulator 27 is used to separate the optical pulse train input to the optical demultiplexer 11 from the multiplexed optical signal train output from the optical demultiplexer 11 in the opposite direction. The modulation operation in the optical modulators 20-1 to 20-8 is the same as in the first embodiment.
【００３３】（第４の実施形態）図５は、本発明の光時
分割多重装置の第４の実施形態を示す。ここでは、光時
分割多重数Ｎ＝８の場合の構成例を示す。(Fourth Embodiment) FIG. 5 shows a fourth embodiment of the optical time division multiplexing apparatus of the present invention. Here, a configuration example when the number of optical time division multiplexing N = 8 is shown.
【００３４】本実施形態は、第２の実施形態の光変調器
３０−１〜３０−８の半導体光増幅器２２−１，２２−
２を反射型にしたことを特徴とする。これにより、光分
波器２１が第２の実施形態における光分波器２１および
光合波器２３として機能し、光分波器１１が第２の実施
形態における光分波器１１および光合波器１４として機
能する折り返し型の構成となる。また、光サーキュレー
タ２７を用い、光分波器１１に入力する光パルス列と、
光分波器１１から逆方向に出力される多重光信号列を分
離する。光変調器３０−１〜３０−８における変調動作
は第２の実施形態と同様である。In the present embodiment, the semiconductor optical amplifiers 22-1 and 22-22 of the optical modulators 30-1 to 30-8 of the second embodiment are used.
2 is a reflection type. Thus, the optical demultiplexer 21 functions as the optical demultiplexer 21 and the optical multiplexer 23 in the second embodiment, and the optical demultiplexer 11 functions as the optical demultiplexer 11 and the optical multiplexer in the second embodiment. It becomes a folded type configuration that functions as 14. Further, an optical pulse train input to the optical demultiplexer 11 using the optical circulator 27,
The multiplexed optical signal sequence output from the optical demultiplexer 11 in the reverse direction is separated. The modulation operation in the optical modulators 30-1 to 30-8 is the same as in the second embodiment.
【００３５】（第５の実施形態）図６は、本発明の光時
分割多重装置の第５の実施形態を示す。ここでは、光時
分割多重数Ｎ＝８の場合の構成例を示す。(Fifth Embodiment) FIG. 6 shows an optical time division multiplexing apparatus according to a fifth embodiment of the present invention. Here, a configuration example when the number of optical time division multiplexing N = 8 is shown.
【００３６】本実施形態は、第１の実施形態の構成にお
いて、８チャネルの光変調信号にそれぞれアシスト光を
合波する光合波器２８−１〜２８−８を備えたものであ
る。これにより、光変調器２０−１〜２０−８の半導体
光増幅器２２−１に、光変調信号とともにアシスト光を
注入することができるので、半導体光増幅器におけるキ
ャリア寿命を早め、相互位相変調のパタン効果を抑制す
ることができる。なお、アシスト光としてはＣＷ光を用
いることができる。This embodiment is different from the first embodiment in that optical multiplexers 28-1 to 28-8 for multiplexing assist light with optical modulation signals of eight channels are provided. As a result, the assist light can be injected together with the optical modulation signal into the semiconductor optical amplifiers 22-1 of the optical modulators 20-1 to 20-8, so that the carrier life in the semiconductor optical amplifier is shortened, and the pattern of the mutual phase modulation is increased. The effect can be suppressed. Note that CW light can be used as the assist light.
【００３７】（第６の実施形態）図７は、本発明の光時
分割多重装置の第６の実施形態を示す。ここでは、光時
分割多重数Ｎ＝８の場合の構成例を示す。(Sixth Embodiment) FIG. 7 shows an optical time division multiplexing apparatus according to a sixth embodiment of the present invention. Here, a configuration example when the number of optical time division multiplexing N = 8 is shown.
【００３８】本実施形態は、第２の実施形態の構成にお
いて、８チャネルの光変調信号にそれぞれアシスト光を
合波する光合波器２８−１〜２８−８を備えたものであ
る。これにより、光変調器３０−１〜３０−８の半導体
光増幅器２２−１，２２−２に、光変調信号とともにア
シスト光を注入することができるので、半導体光増幅器
におけるキャリア寿命を早め、相互位相変調のパタン効
果を抑制することができる。This embodiment is different from the second embodiment in that optical multiplexers 28-1 to 28-8 for multiplexing the assist light with the optical modulation signals of eight channels are provided. Thereby, the assist light can be injected into the semiconductor optical amplifiers 22-1 and 22-2 of the optical modulators 30-1 to 30-8 together with the optical modulation signal, so that the carrier life in the semiconductor optical amplifier is shortened, and The pattern effect of the phase modulation can be suppressed.
【００３９】（第７の実施形態）図８は、本発明の光時
分割多重装置の第７の実施形態を示す。ここでは、光時
分割多重数Ｎ＝８の場合の構成例を示す。(Seventh Embodiment) FIG. 8 shows a seventh embodiment of the optical time division multiplexing apparatus of the present invention. Here, a configuration example when the number of optical time division multiplexing N = 8 is shown.
【００４０】本実施形態は、第１の実施形態の構成にお
いて、入力する光パルス列にアシスト光を合波する光合
波器２９を備えたものである。これにより、光パルス列
とともにアシスト光も８分岐され、光変調器２０−１〜
２０−８の半導体光増幅器２２−１にアシスト光を注入
することができるので、半導体光増幅器におけるキャリ
ア寿命を早め、相互位相変調のパタン効果を抑制するこ
とができる。This embodiment is different from the first embodiment in that an optical multiplexer 29 for multiplexing an assist light with an input optical pulse train is provided. As a result, the assist light is branched into eight along with the optical pulse train, and the optical modulators 20-1 to 20-1 are separated.
Since the assist light can be injected into the 20-8 semiconductor optical amplifier 22-1, the carrier life in the semiconductor optical amplifier can be shortened, and the pattern effect of the cross phase modulation can be suppressed.
【００４１】（第８の実施形態）図９は、本発明の光時
分割多重装置の第８の実施形態を示す。ここでは、光時
分割多重数Ｎ＝８の場合の構成例を示す。(Eighth Embodiment) FIG. 9 shows an eighth embodiment of the optical time division multiplexer of the present invention. Here, a configuration example when the number of optical time division multiplexing N = 8 is shown.
【００４２】本実施形態は、第２の実施形態の構成にお
いて、入力する光パルス列にアシスト光を合波する光合
波器２９を備えたものである。これにより、光パルス列
とともにアシスト光も８分岐され、光変調器３０−１〜
３０−８の半導体光増幅器２２−１，２２−２にアシス
ト光を注入することができるので、半導体光増幅器にお
けるキャリア寿命を早め、相互位相変調のパタン効果を
抑制することができる。This embodiment is different from the second embodiment in that an optical multiplexer 29 for multiplexing an assist light with an input optical pulse train is provided. As a result, the assist light is also branched into eight light beams together with the light pulse train, and the light modulators 30-1 to 30-1.
Since the assist light can be injected into the 30-8 semiconductor optical amplifiers 22-1 and 22-2, the carrier life in the semiconductor optical amplifier can be shortened, and the pattern effect of the cross phase modulation can be suppressed.
【００４３】以上示した第５〜第８の実施形態における
アシスト光を用いる構成は、第２の実施形態または第４
の実施形態に示した光変調器を反射型にした構成にも適
用することができる。The configuration using the assist light in the fifth to eighth embodiments described above is different from that of the second embodiment or the fourth embodiment.
The present invention can be applied to a configuration in which the optical modulator shown in the embodiment is a reflection type.
【００４４】また、以上示した各実施形態は、半導体光
増幅器に対して光パルス列と光変調信号（およびアシス
ト光）を同一方向から入力する例を示したが、光パルス
列と光変調信号（およびアシスト光）を双方向から入力
するようにしてもよい。In each of the embodiments described above, an example is described in which an optical pulse train and an optical modulation signal (and assist light) are input to the semiconductor optical amplifier from the same direction. (Assist light) may be input from both directions.
【００４５】また、以上示した各実施形態において、光
分波器１１から光合波器１４に至るＮチャネルの光導波
路１６−１〜１６−Ｎの途中に、光変調器２０−１〜２
０−Ｎ（３０−１〜３０−Ｎ）に入力される光パルス
列、またはそれから出力される光信号列を増幅する光増
幅器を備えてもよい。In each of the above-described embodiments, the optical modulators 20-1 through 20-N are provided in the middle of the N-channel optical waveguides 16-1 through 16-N from the optical demultiplexer 11 to the optical multiplexer 14.
An optical amplifier for amplifying an optical pulse train input to 0-N (30-1 to 30-N) or an optical signal train output therefrom may be provided.
【００４６】[0046]
【発明の効果】以上説明したように、本発明は、対称マ
ッハツェンダ型干渉部構成に半導体光増幅器を組み合わ
せた光変調器を用いた構成により、光変調信号による変
調ができるので高周波の電気配線が不要になるととも
に、多重化光信号の消光比劣化を改善し、パタン効果も
小さくかつ変換効率も大きな光時分割多重装置を実現す
ることができる。As described above, according to the present invention, since the modulation using the optical modulation signal can be performed by the configuration using the optical modulator in which the semiconductor optical amplifier is combined with the symmetric Mach-Zehnder type interference unit configuration, the high-frequency electric wiring can be realized. It becomes unnecessary, and it is possible to improve the extinction ratio deterioration of the multiplexed optical signal and to realize an optical time division multiplexing device having a small pattern effect and a large conversion efficiency.
【図１】本発明の光時分割多重装置の第１の実施形態を
示す図。FIG. 1 is a diagram showing a first embodiment of an optical time division multiplexing device of the present invention.
【図２】本発明の光時分割多重装置の第２の実施形態を
示す図。FIG. 2 is a diagram showing a second embodiment of the optical time division multiplexing device of the present invention.
【図３】第１の実施形態の光変調器２０および第２の実
施形態の光変調器３０の動作例を示す図。FIG. 3 is a diagram illustrating an operation example of the optical modulator 20 according to the first embodiment and the optical modulator 30 according to the second embodiment.
【図４】本発明の光時分割多重装置の第３の実施形態を
示す図。FIG. 4 is a diagram showing a third embodiment of the optical time division multiplexing device of the present invention.
【図５】本発明の光時分割多重装置の第４の実施形態を
示す図。FIG. 5 is a diagram showing a fourth embodiment of the optical time division multiplexing device of the present invention.
【図６】本発明の光時分割多重装置の第５の実施形態を
示す図。FIG. 6 is a diagram showing a fifth embodiment of the optical time division multiplexing device of the present invention.
【図７】本発明の光時分割多重装置の第６の実施形態を
示す図。FIG. 7 is a diagram showing a sixth embodiment of the optical time division multiplexing device of the present invention.
【図８】本発明の光時分割多重装置の第７の実施形態を
示す図。FIG. 8 is a diagram showing a seventh embodiment of the optical time division multiplexing device of the present invention.
【図９】本発明の光時分割多重装置の第８の実施形態を
示す図。FIG. 9 is a diagram showing an optical time division multiplexing device according to an eighth embodiment of the present invention.
【図１０】従来の光時分割多重装置の構成例を示す図。FIG. 10 is a diagram showing a configuration example of a conventional optical time division multiplexing device.
【図１１】光パルス列の時分割多重化過程を説明する
図。FIG. 11 is a diagram illustrating a time-division multiplexing process of an optical pulse train.
【図１２】各チャネルの遅延時間の変動による影響を説
明する図。FIG. 12 is a view for explaining the influence of fluctuations in the delay time of each channel.
【図１３】従来の集積型の光時分割多重装置の構成例を
示す図。FIG. 13 is a diagram showing a configuration example of a conventional integrated type optical time division multiplexing device.
【図１４】分散シフトファイバのパルス遅延の温度特性
を示す図。FIG. 14 is a diagram showing temperature characteristics of pulse delay of a dispersion-shifted fiber.
【図１５】従来の集積型の光時分割多重装置（光変調信
号駆動）の構成例を示す図。FIG. 15 is a diagram showing a configuration example of a conventional integrated type optical time division multiplexing device (optical modulation signal drive).
【符号の説明】 １１ 光分波器 １２ 光変調器 １３ 光遅延器 １４，１８ 光合波器 １５ 基板 １６，１９ 光導波路 １７ 光変調器 ２０，３０ 光変調器 ２１，２５ 光分波器 ２２ 半導体光増幅器 ２３，２４，２８，２９ 光合波器 ２６ 光導波路 ２７ 光サーキュレータ[Description of Signs] 11 Optical demultiplexer 12 Optical modulator 13 Optical delay device 14, 18 Optical multiplexer 15 Substrate 16, 19 Optical waveguide 17 Optical modulator 20, 30 Optical modulator 21, 25 Optical demultiplexer 22 Semiconductor Optical amplifiers 23, 24, 28, 29 Optical multiplexer 26 Optical waveguide 27 Optical circulator
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.7 識別記号 ＦＩ テーマコート゛(参考） Ｈ０４Ｂ 10/06 Ｈ０４Ｂ 9/00 Ｂ Ｈ０４Ｊ 14/08 Ｈ０４Ｂ 10/00 Ｈ０４Ｊ 3/00 (72)発明者 内山 健太郎 東京都千代田区大手町二丁目３番１号 日 本電信電話株式会社内 (72)発明者 盛岡 敏夫 東京都千代田区大手町二丁目３番１号 日 本電信電話株式会社内 (72)発明者 小川 育生 東京都千代田区大手町二丁目３番１号 日 本電信電話株式会社内 (72)発明者 曲 克明 東京都千代田区大手町二丁目３番１号 日 本電信電話株式会社内 (72)発明者 岡本 稔 東京都千代田区大手町二丁目３番１号 日 本電信電話株式会社内 Ｆターム(参考） 2H079 AA05 AA13 BA01 CA05 CA09 DA16 EA04 EA05 GA03 HA07 HA15 5F073 AB22 AB25 AB29 AB30 BA01 EA14 5K002 AA02 BA02 BA04 BA05 CA13 CA14 DA06 DA31 FA01 5K028 AA01 BB08 KK03 LL11 ──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. 7 Identification symbol FI Theme coat ゛ (Reference) H04B 10/06 H04B 9/00 B H04J 14/08 H04B 10/00 H04J 3/00 (72) Inventor Uchiyama Kentaro 2-3-1, Otemachi, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation (72) Inventor Toshio Morioka 2-3-1, Otemachi, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation (72) Invention Ikuo Ogawa 2-3-1 Otemachi, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation (72) Inventor Katsuaki Song 2-3-1, Otemachi, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation (72 Inventor Minoru Okamoto 2-3-1 Otemachi, Chiyoda-ku, Tokyo F-term in Nippon Telegraph and Telephone Corporation (reference) 2H079 AA05 AA13 BA01 CA05 CA09 DA16 EA04 EA05 GA03 H A07 HA15 5F073 AB22 AB25 AB29 AB30 BA01 EA14 5K002 AA02 BA02 BA04 BA05 CA13 CA14 DA06 DA31 FA01 5K028 AA01 BB08 KK03 LL11
Claims (6)
し、Ｎチャネル（Ｎは２以上の整数）に分波するＮチャ
ネル光分波器と、 前記光パルス列に同期したＮチャネルの光変調信号を入
力し、それぞれ対応するチャネルの光パルス列の強度ま
たは位相をそれぞれ変調してビットレートｆ0の光信号
列に変換するＮ個の光変調器と、 前記各光変調器から出力された光信号列を合波するＮチ
ャネル光合波器と、 前記Ｎチャネル光分波器から前記Ｎチャネル光合波器に
至るＮチャネルの経路を異なる長さで結合し、各チャネ
ルの光信号列にそれぞれ異なる遅延を与えるＮ本の光導
波路と、 前記Ｎチャネル光分波器、前記Ｎ個の光変調器、前記Ｎ
チャネル光合波器、前記Ｎ本の光導波路を集積化する基
板とを備え、 前記Ｎチャネル光合波器からビットレートＮ・ｆ0 の多
重光信号列を出力する光時分割多重装置において、 前記各光変調器は、入力する光パルス列を２分岐する光
分波器と、その２経路に挿入される２つの半導体光増幅
器と、各半導体光増幅器の出力を合波する光合波器とか
らなる対称マッハツェンダ型干渉部を構成し、その一方
の経路に挿入した光変調信号用光合波器を介して、前記
光変調信号を一方の半導体光増幅器に入力し、２つの半
導体光増幅器から光変調信号によって位相変調を受けた
光パルス列と位相変調を受けない光パルス列を出力し、
光合波器から前記光変調信号に対応する強度変調された
光信号列を出力する構成であることを特徴とする光時分
割多重装置。1. An N-channel optical demultiplexer that receives an optical pulse train having a repetition frequency f 0 and splits the signal into N channels (N is an integer of 2 or more), and an N-channel optical modulation signal synchronized with the optical pulse train. And N optical modulators for respectively modulating the intensity or phase of the optical pulse train of the corresponding channel to convert the optical pulse train into an optical signal train of a bit rate f 0 , and an optical signal output from each of the optical modulators N-channel optical multiplexers for multiplexing columns, and N-channel paths from the N-channel optical demultiplexer to the N-channel optical multiplexer are coupled with different lengths, and the optical signal trains of each channel have different delays. N optical waveguides that provide: N channel optical demultiplexer, N optical modulators, N
An optical time-division multiplexing device, comprising: a channel optical multiplexer; a substrate on which the N optical waveguides are integrated; and outputting a multiplexed optical signal train having a bit rate of N · f 0 from the N-channel optical multiplexer. The optical modulator has a symmetrical configuration including an optical demultiplexer that branches an input optical pulse train into two, two semiconductor optical amplifiers inserted into the two paths, and an optical multiplexer that multiplexes the output of each semiconductor optical amplifier. A Mach-Zehnder type interference unit is formed, and the optical modulation signal is input to one semiconductor optical amplifier via an optical modulator for optical modulation signal inserted into one of the paths, and the optical modulation signal is output from the two semiconductor optical amplifiers. Outputting an optical pulse train subjected to phase modulation and an optical pulse train not subject to phase modulation,
An optical time-division multiplexing device having a configuration in which an optical signal train that is intensity-modulated corresponding to the optical modulation signal is output from an optical multiplexer.
し、Ｎチャネル（Ｎは２以上の整数）に分波するＮチャ
ネル光分波器と、 前記光パルス列に同期したＮチャネルの光変調信号を入
力し、それぞれ対応するチャネルの光パルス列の強度ま
たは位相をそれぞれ変調してビットレートｆ0の光信号
列に変換するＮ個の光変調器と、 前記各光変調器から出力された光信号列を合波するＮチ
ャネル光合波器と、 前記Ｎチャネル光分波器から前記Ｎチャネル光合波器に
至るＮチャネルの経路を異なる長さで結合し、各チャネ
ルの光信号列にそれぞれ異なる遅延を与えるＮ本の光導
波路と、 前記Ｎチャネル光分波器、前記Ｎ個の光変調器、前記Ｎ
チャネル光合波器、前記Ｎ本の光導波路を集積化する基
板とを備え、 前記Ｎチャネル光合波器からビットレートＮ・ｆ0 の多
重光信号列を出力する光時分割多重装置において、 前記基板上に、Ｎチャネルの光変調信号をそれぞれ２分
岐するＮ個の光変調信号用光分波器と、それぞれ２分岐
された２つの光変調信号との間に所定の位相差（遅延）
を与えて前記各光変調器に入力する光導波路とを集積化
し、 前記各光変調器は、入力する光パルス列を２分岐する光
分波器と、その２経路に挿入される２つの半導体光増幅
器と、各半導体光増幅器の出力を合波する光合波器とか
らなる対称マッハツェンダ型干渉部を構成し、各経路に
それぞれ挿入された光変調信号用光合波器を介して、前
記所定の位相差を有する２つの光変調信号を２つの半導
体光増幅器にそれぞれ入力し、２つの半導体光増幅器か
ら光変調信号によって位相変調を受けた光パルス列を出
力し、光合波器から光変調信号に対応する強度変調され
た光信号列を出力する構成であることを特徴とする光時
分割多重装置。2. An N-channel optical demultiplexer that receives an optical pulse train having a repetition frequency f 0 and splits the signal into N channels (N is an integer of 2 or more), and an N-channel optical modulation signal synchronized with the optical pulse train. And N optical modulators for respectively modulating the intensity or phase of the optical pulse train of the corresponding channel to convert the optical pulse train into an optical signal train of a bit rate f 0 , and an optical signal output from each of the optical modulators N-channel optical multiplexers for multiplexing columns, and N-channel paths from the N-channel optical demultiplexer to the N-channel optical multiplexer are coupled with different lengths, and the optical signal trains of each channel have different delays. N optical waveguides that provide: N channel optical demultiplexer, N optical modulators, N
An optical time-division multiplexing device, comprising: a channel optical multiplexer; and a substrate on which the N optical waveguides are integrated; and outputting a multiplexed optical signal train having a bit rate of N · f 0 from the N-channel optical multiplexer. Above, a predetermined phase difference (delay) between N optical modulation signal optical demultiplexers, each of which divides an N-channel optical modulation signal into two, and two optical modulation signals, each of which branches into two.
And an optical waveguide to be input to each of the optical modulators is integrated. Each of the optical modulators includes an optical demultiplexer that divides an input optical pulse train into two, and two semiconductor lights inserted into the two paths. A symmetric Mach-Zehnder type interference unit comprising an amplifier and an optical multiplexer for multiplexing the outputs of the respective semiconductor optical amplifiers is formed, and the predetermined position is transmitted via the optical modulation signal optical multiplexers respectively inserted in the respective paths. Two optical modulation signals having a phase difference are respectively input to two semiconductor optical amplifiers, and an optical pulse train subjected to phase modulation by the optical modulation signals is output from the two semiconductor optical amplifiers, and the optical multiplexers correspond to the optical modulation signals. An optical time-division multiplexing device having a configuration for outputting an intensity-modulated optical signal sequence.
割多重装置において、 前記各光変調器は、前記対称マッハツェンダ型干渉部の
２経路部分で反射する構成として光分波器と光合波器を
共用する構成とし、 前記Ｎチャネル光分波器と前記Ｎチャネル光合波器を共
用する構成とすることを特徴とする光時分割多重装置。3. The optical time-division multiplexing device according to claim 1, wherein each of the optical modulators has an optical demultiplexer and an optical demultiplexer configured to reflect at two paths of the symmetric Mach-Zehnder interference unit. An optical time-division multiplexing device, wherein the optical time-division multiplexing device is configured to share the optical multiplexer, and the N-channel optical demultiplexer and the N-channel optical multiplexer are shared.
の光時分割多重装置において、 前記光変調信号または前記光パルス列にＣＷ光を合波し
て前記半導体光増幅器に入力するＣＷ光用光合波器を備
えたことを特徴とする光時分割多重装置。4. The optical time division multiplexing device according to claim 1, wherein CW light is multiplexed with the optical modulation signal or the optical pulse train and input to the semiconductor optical amplifier. An optical time division multiplexing device comprising an optical multiplexer.
の光時分割多重装置において、 前記基板上で、前記光変調器の前段または後段に光増幅
器を集積化することを特徴とする光時分割多重装置。5. The optical time-division multiplexing device according to claim 1, wherein an optical amplifier is integrated on the substrate before or after the optical modulator. Optical time division multiplexer.
の光時分割多重装置において、 前記光導波路を形成する基板として半導体基板または石
英系基板またはセラミック系基板を用いることを特徴と
する光時分割多重装置。6. The optical time division multiplexing device according to claim 1, wherein a semiconductor substrate, a quartz substrate, or a ceramic substrate is used as a substrate on which the optical waveguide is formed. Optical time division multiplexer.
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|---|---|---|---|
| JP2001031571A JP2002236271A (en) | 2001-02-07 | 2001-02-07 | Optical time division multiplexer |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001031571A JP2002236271A (en) | 2001-02-07 | 2001-02-07 | Optical time division multiplexer |
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|---|---|
| JP2002236271A true JP2002236271A (en) | 2002-08-23 |
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|---|---|---|---|
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100399049B1 (en) * | 2001-04-16 | 2003-09-26 | 한국전자통신연구원 | High wavelength selector, and multi-channel selector for space and wavelength in high speed optical integrated circuit using the High wavelength selector |
| JP2010103614A (en) * | 2008-10-21 | 2010-05-06 | Nippon Telegr & Teleph Corp <Ntt> | Optical communication system, optical transmitter, and optical transmission method |
| US7869599B2 (en) | 2003-10-10 | 2011-01-11 | Nec Corporation | Quantum cryptography key distributing system and synchronizing method used in the same |
| WO2014129613A1 (en) * | 2013-02-25 | 2014-08-28 | カナレ電気株式会社 | Optical amplifier and laser oscillator |
| CN117097431A (en) * | 2023-10-16 | 2023-11-21 | 鹏城实验室 | Time delay control equipment, optical time division multiplexing method, demultiplexing method and system |
-
2001
- 2001-02-07 JP JP2001031571A patent/JP2002236271A/en active Pending
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100399049B1 (en) * | 2001-04-16 | 2003-09-26 | 한국전자통신연구원 | High wavelength selector, and multi-channel selector for space and wavelength in high speed optical integrated circuit using the High wavelength selector |
| US7869599B2 (en) | 2003-10-10 | 2011-01-11 | Nec Corporation | Quantum cryptography key distributing system and synchronizing method used in the same |
| JP2010103614A (en) * | 2008-10-21 | 2010-05-06 | Nippon Telegr & Teleph Corp <Ntt> | Optical communication system, optical transmitter, and optical transmission method |
| WO2014129613A1 (en) * | 2013-02-25 | 2014-08-28 | カナレ電気株式会社 | Optical amplifier and laser oscillator |
| CN117097431A (en) * | 2023-10-16 | 2023-11-21 | 鹏城实验室 | Time delay control equipment, optical time division multiplexing method, demultiplexing method and system |
| CN117097431B (en) * | 2023-10-16 | 2024-03-19 | 鹏城实验室 | Time delay control equipment, optical time division multiplexing method, demultiplexing method and system |
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