JPH01189976A - Oscillation frequency interval stabilizing device for plural lasers - Google Patents
Oscillation frequency interval stabilizing device for plural lasersInfo
- Publication number
- JPH01189976A JPH01189976A JP63016191A JP1619188A JPH01189976A JP H01189976 A JPH01189976 A JP H01189976A JP 63016191 A JP63016191 A JP 63016191A JP 1619188 A JP1619188 A JP 1619188A JP H01189976 A JPH01189976 A JP H01189976A
- Authority
- JP
- Japan
- Prior art keywords
- oscillation frequency
- laser
- optical
- laser device
- lasers
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 230000010355 oscillation Effects 0.000 title claims abstract description 71
- 230000000087 stabilizing effect Effects 0.000 title claims abstract description 10
- 230000003287 optical effect Effects 0.000 claims abstract description 63
- 230000006641 stabilisation Effects 0.000 claims abstract description 10
- 238000011105 stabilization Methods 0.000 claims abstract description 10
- 239000011324 bead Substances 0.000 claims description 7
- 238000000034 method Methods 0.000 abstract description 8
- 238000002347 injection Methods 0.000 abstract description 4
- 239000007924 injection Substances 0.000 abstract description 4
- 238000004891 communication Methods 0.000 description 8
- 238000010586 diagram Methods 0.000 description 4
- 239000013307 optical fiber Substances 0.000 description 3
- 238000001228 spectrum Methods 0.000 description 3
- 101000878457 Macrocallista nimbosa FMRFamide Proteins 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 238000005070 sampling Methods 0.000 description 2
- BJQHLKABXJIVAM-UHFFFAOYSA-N bis(2-ethylhexyl) phthalate Chemical compound CCCCC(CC)COC(=O)C1=CC=CC=C1C(=O)OCC(CC)CCCC BJQHLKABXJIVAM-UHFFFAOYSA-N 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 210000003127 knee Anatomy 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 238000011017 operating method Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/50—Transmitters
- H04B10/572—Wavelength control
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S5/00—Semiconductor lasers
- H01S5/06—Arrangements for controlling the laser output parameters, e.g. by operating on the active medium
- H01S5/068—Stabilisation of laser output parameters
- H01S5/0683—Stabilisation of laser output parameters by monitoring the optical output parameters
- H01S5/0687—Stabilising the frequency of the laser
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/50—Transmitters
- H04B10/501—Structural aspects
- H04B10/506—Multiwavelength transmitters
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S5/00—Semiconductor lasers
- H01S5/40—Arrangement of two or more semiconductor lasers, not provided for in groups H01S5/02 - H01S5/30
- H01S5/4025—Array arrangements, e.g. constituted by discrete laser diodes or laser bar
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は、周波数多重光通信の送信側に用いられ、複数
のレーザ装置間の発振周波数間隔を、基準となる１台の
光学共振器を用いて一定に保つ複数レーザ装置発振周波
数間隔安定化装置に関する。Detailed Description of the Invention (Industrial Application Field) The present invention is used on the transmitting side of frequency multiplexed optical communication, and is used to adjust the oscillation frequency interval between multiple laser devices using one optical resonator as a reference. The present invention relates to a device for stabilizing the oscillation frequency interval of a plurality of laser devices to keep it constant.
（従来の技術）
光通信システムにおいてはその伝送路である光ファイバ
の広帯域性を利用するために波長多重光通信が行なわれ
ている。しかし現状の波長多重光通信では、直接検波を
用いているので、そあ波長間隔は光受信部において各波
長の信号を分離するために用いられる光分波器の分解能
によって制限される、そのため通常は波長間隔を１０ｎ
１１以上に設定しており、必ずしも光ファイバの広帯域
性を十分には利用していない、これに対し光受信部にお
いて光ヘテロダイン検波を行なうと、各信号の分離を電
気領域で行なうことが可能になり電気領域においてわず
かに周波数が異なるような光多重伝送が可能になる（大
越“光ヘテロダインもしくは光ホモダイン型用波数多重
光ファイバ通信の可能性と問題点の検討”電子通信学会
光量ニレ研資料ＯＱ Ｅ ７８−１２９． （１９７９
） ） 。(Prior Art) In optical communication systems, wavelength division multiplexing optical communication is performed to take advantage of the broadband properties of optical fibers, which are transmission paths. However, current wavelength multiplexing optical communication uses direct detection, so the wavelength spacing is limited by the resolution of the optical demultiplexer used to separate the signals of each wavelength in the optical receiver. is the wavelength interval of 10n
11 or higher, which does not necessarily take full advantage of the broadband properties of optical fibers.On the other hand, if optical heterodyne detection is performed in the optical receiver, it is possible to separate each signal in the electrical domain. In the electrical domain, optical multiplexing transmission with slightly different frequencies becomes possible (Okoshi "Study of possibilities and problems of wavenumber multiplexing optical fiber communication for optical heterodyne or optical homodyne type" Institute of Electronics and Communications Engineers of Japan Optical Quantity Nire Research Material OQ E 78-129. (1979
)).
しかし単一の局部発振光源で複数の信号光を電気領域の
周波数に変換するには、各信号間の周波数間隔を一定に
保っておかなければ、電気領域で信号相互が重なったり
、帯域外に信号がはずれるという現象がおこり、各信号
を劣化なく分離することができない、しかし、光源とし
て半導体レーザを用いる場合にはその発振周波数が温度
、注入電流の変化に対応して大きく変化し、スガスレー
ザ等の場合にはその共振器間隔の変動などにともなって
発振周波数が変動する。従って電気領域で周波数多重さ
れるほどの稠密な多重を、復調時に劣化がないように行
なうことは難しいという問題点があった。従って上記の
ような周波数多重光通信を行なうには、送信側の複数の
レーザ装置間の発振周波数間隔をなんらかの制御によっ
て安定化することが必要となる。However, in order to convert multiple optical signals to frequencies in the electrical domain using a single local oscillation light source, the frequency interval between each signal must be kept constant, otherwise the signals may overlap in the electrical domain or go out of band. However, when a semiconductor laser is used as a light source, its oscillation frequency changes greatly in response to changes in temperature and injected current. In this case, the oscillation frequency fluctuates as the resonator spacing changes. Therefore, there is a problem in that it is difficult to perform dense multiplexing such as frequency multiplexing in the electrical domain without causing deterioration during demodulation. Therefore, in order to perform the above-mentioned frequency multiplexed optical communication, it is necessary to stabilize the oscillation frequency interval between the plurality of laser devices on the transmitting side by some kind of control.
従来は、複数のレーザ装置の周波数間隔を安定化させる
方式としては、１つのレーザ装置の発振周波数をファプ
リーベロー共振器に対して安定化し、このレーザ装置の
発振周波数に対し、他のレーザ装置の発振周波数を互い
の周波数間隔が別のファプリーペロー共振器のフリース
ベクトルレンジにより与えられる周波数間隔基準と一致
するように安定化するという方法（鳥羽ら、昭和６１年
度電子通信学会通信部門全国大会予稿集、分冊２゜２−
２０ページ）、あるいは１つのレーザ装置の周波数を安
定化し、他のいくつかのレーザ装置出射光と合波し、さ
らにこの光と周波数を一定周期の鋸歯状に掃引している
参照用レーザ装置出射光を合波し、ビード信号として得
られるパルス列を構成する各パルスの出現時刻が上記安
定化レーザ装置に対応するパルスの出現時刻に対して一
定時間差を保っているかをモニタすることにより各レー
ザ装置の発振周波数間隔を安定化する方式（シュトレー
ベルらによるアイ・オー・オー・シー−イー・シー・オ
ー・シー’８５（１００Ｃ−ＥＣＯＣ’ ８５）テクニ
カルダイジェスト第３巻（１９８５年）６１ページ）が
知られている。Conventionally, as a method for stabilizing the frequency interval of multiple laser devices, the oscillation frequency of one laser device is stabilized with respect to the Fapley-Bello resonator, and the oscillation frequency of this laser device is stabilized with respect to the oscillation frequency of other laser devices. A method of stabilizing the oscillation frequencies of the oscillators so that their frequency spacing matches the frequency spacing standard given by the Fries vector range of another Fapley-Perot resonator (Toba et al., 1988 IEICE Communications Division National Conference Proceedings, Volume 2゜2-
(page 20), or a reference laser device output that stabilizes the frequency of one laser device, combines it with the light emitted from several other laser devices, and then sweeps this light and frequency in a sawtooth pattern with a constant period. Each laser device combines the emitted light and monitors whether the appearance time of each pulse constituting the pulse train obtained as a bead signal maintains a certain time difference from the appearance time of the pulse corresponding to the stabilized laser device. A method for stabilizing the oscillation frequency interval (Strebel et al., IOOC'85 (100C-ECOC'85) Technical Digest Vol. 3 (1985), page 61) It has been known.
（発明が解決しようとする課題）
しかし、上記第一の方式においては、周波数間隔の基準
を与えるファプリーベロー共振器のミラー間隔を掃引し
て使用する必要があり、単なるエタロン板を使用する場
合に比べ装置が大型化する。また第二の方式においては
、周波数間隔の基準を参照用レーザ装置の周波数変化に
対する各パルスの出現時刻間隔に求めているから、各レ
ーザ装置の周波数間隔が確定されうるとは言い難い。(Problem to be Solved by the Invention) However, in the first method described above, it is necessary to sweep the mirror spacing of the Fapley bellows resonator that provides the reference for the frequency spacing, and when using a simple etalon plate, The equipment is larger than the previous one. Furthermore, in the second method, since the frequency interval is determined by the appearance time interval of each pulse with respect to the frequency change of the reference laser device, it is difficult to say that the frequency interval of each laser device can be determined.
本発明は、上記従来の第１の方式にみられるようにファ
プリーペロー共振器の共振器長を掃引して使用する故に
装置全体が大型化するという問題点がなく、かつ上記従
来の第２の方式にみられるように安定化した発振周波数
間隔が厳密に規定されていないという問題点がない、複
数のレーザ装置間の発振周波数間隔安定化装置を提供す
ることを目的とする。The present invention does not have the problem of increasing the size of the entire device because the resonator length of the Farpley-Perot resonator is swept and used as seen in the first conventional method, and the present invention does not have the problem of increasing the size of the entire device as seen in the first conventional method. It is an object of the present invention to provide a device for stabilizing oscillation frequency intervals between a plurality of laser devices, which does not have the problem that the stabilized oscillation frequency intervals are not strictly defined as seen in the above method.
（課題を解決するための手段）
前述の課題を解決し上記目的を達成するために本発明が
提供する複数レーザ装置発振周波数間隔安定化装置は、
発振周波数間隔安定化の対象となる複数のレーザ装置の
出射光を合波する第１の光合波器と、前記複数の発振周
波数間隔安定化対象レーザ装置の発振周波数を含む範囲
で発振周波数を掃引する参照用レーザ装置と、該参照用
レーザ装πの出射光を入射する光学共振器と、該光学共
振器の出射光と前記第１の光合波器の出射光とを合波す
る第２の光合波器と、該第２の光合波器の出力光を受光
して前記光学共振器を通過した前記参照用レーザ装置出
射光と前記複数の発振周波数間隔安定化対象レーザ装置
出射光のビードを検出する光検出器と、前記複数の発振
周波間隔安定化対象レーザ装置の発振周波数を前記光学
共振器の互いに異なった複数の共振周波数にそれぞれ安
定化させる制御信号を前記光検出器の出力に基づき生成
し、該発振周波数間隔安定化対象レーザ装置に供給する
レーザ周波数制御手段とを含んでなることを特徴とする
。(Means for Solving the Problems) In order to solve the above problems and achieve the above objects, the present invention provides a device for stabilizing the oscillation frequency spacing of multiple laser devices.
a first optical multiplexer that combines emitted light from a plurality of laser devices that are targets for oscillation frequency interval stabilization, and sweeps the oscillation frequency in a range that includes the oscillation frequencies of the plurality of laser devices that are targets for oscillation frequency interval stabilization. a reference laser device, an optical resonator into which the light emitted from the reference laser device π enters, and a second optical resonator which combines the light emitted from the optical resonator and the light emitted from the first optical multiplexer. an optical multiplexer, and a bead of the reference laser device output light that received the output light of the second optical multiplexer and passed through the optical resonator, and the output light of the plurality of oscillation frequency interval stabilization target laser devices. A control signal is provided based on the output of the photodetector to stabilize the oscillation frequencies of the photodetector to be detected and the laser devices to be stabilized at the plurality of oscillation frequency intervals to a plurality of mutually different resonance frequencies of the optical resonator. and a laser frequency control means for generating and supplying the generated oscillation frequency interval to the laser device whose oscillation frequency interval is to be stabilized.
（作用）
本発明では上記のような構成をとることにより、光学共
振器を通過した参照用レーザ装置の出射光は、単に周波
数が挿引されているだけではなく、光学共振器の共振周
波数でその強度が最大になるように変調される。この参
照用レーザ光と、制御対象たるレーザ装置の出射光との
ビードをとり、このビードが最大になるように制御をか
けることにより制御対象たるレーザ装置の発振周波数を
光学共振器の共振周波数に安定化できる。または参照用
レーザ光強度が最大になる時刻と、ビード強度が最大に
なる時刻とが一致するように制御をかけることにより制
御対象たるレーザ装置の発振周波数を光学共振器の共振
周波数に安定化できる。(Function) In the present invention, by adopting the above-described configuration, the emitted light of the reference laser device that has passed through the optical resonator not only has its frequency added or subtracted, but also has the resonant frequency of the optical resonator. It is modulated so that its intensity is maximized. The oscillation frequency of the laser device to be controlled is adjusted to the resonant frequency of the optical resonator by taking a bead between this reference laser beam and the emitted light of the laser device to be controlled, and controlling this bead to the maximum. It can be stabilized. Alternatively, the oscillation frequency of the laser device to be controlled can be stabilized to the resonant frequency of the optical resonator by controlling the time when the reference laser beam intensity reaches its maximum and the time when the bead intensity reaches its maximum. .
そして、上記の制御を参照用レーザ周波数の挿引に同期
をとりながら複数のレーザ装置に個別にがけることによ
り、複数のレーザ装置の発振周波数を一台の光学共振器
の異なる共振周波数に安定化できる。この場合、光学共
振器の共振周波数間隔は安定であるから以上の制御によ
り複数のレーザ装置間の発振周波数間隔が安定化される
。By applying the above control to multiple laser devices individually in synchronization with the addition and subtraction of the reference laser frequency, the oscillation frequencies of multiple laser devices are stabilized to different resonance frequencies of one optical resonator. can be converted into In this case, since the resonance frequency interval of the optical resonator is stable, the oscillation frequency interval between the plurality of laser devices is stabilized by the above control.
（実施例） 以下に実施例を挙げ、本発明を一層詳しく説明する。(Example) The present invention will be explained in more detail with reference to Examples below.
第１図は本発明の第１の実施例の構成を示すブロック図
である。この第１の実施例では３台のレーザ装置１，２
．３の発振周波数間隔が安定化できる。３台のレーザ装
置１，２．３は１．５５回帯位相制御領域付分布反射型
レーザと、レーザ温度安定化装置と、反射戻り光防止用
光アイソレータとを内蔵したモジュールであり、変調器
７．８．９によってレーザ注入電流に印加される変調信
号に従ってその発振周波数にはビットレート４００Ｈｂ
／ｓ、最大周波数閤移量ＩＧＨ工のＦＳＫ変調が加えら
れる。FIG. 1 is a block diagram showing the configuration of a first embodiment of the present invention. In this first embodiment, three laser devices 1 and 2 are used.
．． The oscillation frequency interval of 3 can be stabilized. The three laser devices 1, 2.3 are modules that incorporate a distributed reflection laser with a 1.55-band phase control region, a laser temperature stabilization device, and an optical isolator for preventing reflected return light. According to the modulation signal applied to the laser injection current by 7.8.9, its oscillation frequency has a bit rate of 400Hb.
/s, FSK modulation with maximum frequency shift IGH is applied.
参照用レーザ装置１１は、１．５５−帯位相制御領域付
分布ブラッグ反射型レーザと、レーザ温度安定化装置と
、反射戻り光防止用光アイソレータとを内蔵したモジュ
ールである。この参照用レーザ装置１１の発振周波数は
、鋸歯状波発生器１０によって印加される繰返し周波数
／ＫＨアの信号に従い、時間に対し鋸歯状に最大周波数
偏移１３０ＧＨｚで連続掃引される。なお位相制御領域
付分布ブラッグ反射型レーザの構造、特性についてはた
とえばエレクトロニクス・レターズ第２３巻第８号４０
３ページ所載の材用らによる論文に詳しい。The reference laser device 11 is a module incorporating a distributed Bragg reflection type laser with a 1.55-band phase control region, a laser temperature stabilization device, and an optical isolator for preventing reflected return light. The oscillation frequency of this reference laser device 11 is continuously swept in a sawtooth manner with respect to time with a maximum frequency deviation of 130 GHz according to a signal of repetition frequency/KHA applied by the sawtooth wave generator 10. Regarding the structure and characteristics of the distributed Bragg reflection type laser with a phase control region, see, for example, Electronics Letters, Vol. 23, No. 8, 40.
For details, see the paper by Zaiyo et al. on page 3.
参照用レーザ装置１１の出射光は、光共振器１２を通過
し、光分波器１４において分波される。光共振器１２と
して、フリースペクトラムレンジ１０ＧＨ工、フィネル
１０のファプリーへロー共振器を用いた。参照用レーザ
装置１１の周波数挿引範囲は３０ＧＨｚなので、この周
波数挿引範囲内には、光学共振器１２の３個の共振ピー
クが含まれている。The emitted light from the reference laser device 11 passes through the optical resonator 12 and is demultiplexed by the optical demultiplexer 14 . As the optical resonator 12, a Fapley-Helow resonator manufactured by Free Spectrum Range 10GH and Finnel 10 was used. Since the frequency sampling range of the reference laser device 11 is 30 GHz, three resonance peaks of the optical resonator 12 are included within this frequency sampling range.
以下、この３つの共振ピークを共振周波数が低い順に共
振ピークＡ、共振ピークＢ、共振ピークＣとよぶ。Hereinafter, these three resonance peaks will be referred to as resonance peak A, resonance peak B, and resonance peak C in descending order of resonance frequency.
３台のレーザ装置１，２．３の出射光は光合波器１３で
合波され、さらに光分波器１４で分波された参照用レー
ザ装置１１の出射光の１つと光合波器１５で合波された
後、光検出器１６によって電気信号に変換される。この
光検出器１６の出力は２つに分けられ、片方は遮断周波
数５００ＭＨ，の低域通過フィルタ１７を通過した後、
検波器１８によって検波され、もう片方はカウンタ１９
に入力される。The emitted light from the three laser devices 1, 2.3 is combined by an optical multiplexer 13, and further demultiplexed by an optical demultiplexer 14 and one of the emitted lights from the reference laser device 11 and an optical multiplexer 15. After being combined, the light is converted into an electrical signal by the photodetector 16. The output of this photodetector 16 is divided into two parts, one of which passes through a low-pass filter 17 with a cutoff frequency of 500 MH.
The wave is detected by the detector 18, and the other side is detected by the counter 19.
is input.
参照用レーザ装置１１と３台のレーザ装置１，２゜３の
発振周波数差がほぼ±５００ Ｍ Ｈｚの範囲に入って
いる場合に検波器１８の出力には両者のビード信号が現
われ、その強度は、制御対象たるレーザ装置１．２．３
のいずれかの発振周波数が光学共振器１２の共振ピーク
の中心周波数に一致したとき最大Ｃニーなる。従って、
装置の立ち上げ時に検波器１８及びカウンタ１９の出力
をモニタしながらレーザ装Ｔｔ１．２．３の注入電流を
それぞれ変化させ。When the oscillation frequency difference between the reference laser device 11 and the three laser devices 1, 2, and 3 is within the range of approximately ±500 MHz, bead signals of both appear in the output of the detector 18, and their intensity is the laser device to be controlled 1.2.3
When any of the oscillation frequencies coincides with the center frequency of the resonance peak of the optical resonator 12, the maximum C knee is reached. Therefore,
At startup of the device, the injection currents of the laser devices Tt1, 2, and 3 are varied while monitoring the outputs of the detector 18 and counter 19.
レーザ装置１の発振周波数を前記共振ピークＡ付近にし
、レーザ装置２の発振周波数を前記共振ピークＢ付近に
し、レーザ装置３の発振周波数を前記共振ピークＣ付近
にした。あとは、制御装置２０内においてカウンタ１９
の出力によって参照用レーザ装置１１の掃引と同期をと
りながら、レーザ装置１．２．３の発振周波数がそれぞ
れ前記共振ピークＡ、Ｂ、Ｃの中心周波数に一致するよ
うに、すなわち検波器１８の出力が最大になるようにい
わゆる最大値制御を個別に行なった。The oscillation frequency of the laser device 1 was set near the resonance peak A, the oscillation frequency of the laser device 2 was set near the resonance peak B, and the oscillation frequency of the laser device 3 was set near the resonance peak C. After that, the counter 19 in the control device 20
While synchronizing with the sweep of the reference laser device 11 by the output of So-called maximum value control was performed individually to maximize the output.
上記の最大値制御により、制御装置２０からレーザ装ｆ
ｌ、２．３を個別に制御する制御信号をレーザ周波数制
御装置４，５．６に出力することによって、レーザ装置
１．２．３の発振周波数をそれぞれ前記共振ピークＡ、
Ｂ、Ｃに固定した。By the maximum value control described above, the laser device f is controlled by the control device 20.
By outputting control signals for individually controlling the laser devices 1, 2.3 to the laser frequency control devices 4, 5.6, the oscillation frequency of the laser device 1.2.3 is adjusted to the resonance peak A, 2.3, respectively.
Fixed to B and C.
以上の操作により、レーザ装置１．２．３の発振周波数
間隔を光学共振器１２のフリースペクトラムレンジであ
る１０Ｇ Ｈアに安定化することができた。この場合、
レーザ装置１の発振周波数くレーザ装置２の発振周波数
くレーザ装置３の発振周波数であるが、制御装置２０の
初期設定、および装置の立ち上げ時の操作の手順の変更
によって、この順番は変更できる。Through the above operations, it was possible to stabilize the oscillation frequency interval of the laser device 1.2.3 to 10 GH, which is the free spectrum range of the optical resonator 12. in this case,
The oscillation frequency of the laser device 1, the oscillation frequency of the laser device 2, and the oscillation frequency of the laser device 3. However, this order can be changed by changing the initial settings of the control device 20 and the operating procedure when starting up the device. .
以上の第１の実施例では３台のレーザ装置１゜２．３の
発振周波数間隔を１０ＧＨｚに安定化するものであった
が、参照用レーザ装置１１の掃引範囲を拡大することに
よって３台以上のレーザ装置の発振周波数間隔を安定化
することが可能である。In the first embodiment described above, the oscillation frequency interval of three laser devices 1°2.3 was stabilized at 10 GHz, but by expanding the sweep range of the reference laser device 11, three or more laser devices It is possible to stabilize the oscillation frequency interval of the laser device.
さらに、光学共振器１２のフリースペクトラムレンジを
変えることによって、レーザ装置間の発振周波数間隔を
変えることができる。また第１の実施例では複数のレー
ザ装置１，２．３のレーザ注入電流に変調をかけて出射
光をＦＳＫ変調したが、それ以外にＰＳＫ変調、ＡＳＫ
変調等のいかなる変調（無変調を含む）をかけても第１
の実施例同様、最大値制御によって各レーザ装置間の発
振周波数間隔を安定化することが可能である。Furthermore, by changing the free spectrum range of the optical resonator 12, the oscillation frequency interval between laser devices can be changed. In addition, in the first embodiment, the laser injection currents of the plurality of laser devices 1, 2.3 are modulated and the emitted light is FSK modulated, but in addition to that, PSK modulation, ASK modulation, etc.
No matter what kind of modulation (including no modulation) is applied, the first
As in the embodiment, it is possible to stabilize the oscillation frequency interval between each laser device by controlling the maximum value.
第１の実施例の変形例として、第１の実施例の装置を２
組ならべ、そのうちの鋸歯状波発生装置１０、参照用レ
ーザ装置１１．光共振器１２および光分波器１４を共通
化した構成が可能である。すなわち１台の参照用レーザ
装置１１を用いてその出射光を光分波器１４で２分岐す
ることにより、３台のレーザ装置の組を２組対象にして
、発振周波数間隔の安定化を行なうことができる。さら
に光分波器１４の分岐数を増すことによって１台の参照
用レーザ装置を用いて複数組のレーザ装置の組の発振周
波数間隔を安定化することも可能である。As a modification of the first embodiment, the device of the first embodiment is
The sawtooth wave generator 10, the reference laser device 11. A configuration in which the optical resonator 12 and the optical demultiplexer 14 are shared is possible. That is, by using one reference laser device 11 and splitting its emitted light into two by the optical demultiplexer 14, the oscillation frequency interval is stabilized for two sets of three laser devices. be able to. Furthermore, by increasing the number of branches of the optical demultiplexer 14, it is also possible to stabilize the oscillation frequency intervals of a plurality of laser device sets using one reference laser device.
第２図は本発明の第２の実施例の構成を示すブロック図
である。第１図の実施例においては、各レーザ装置の発
振周波数をそれぞれ光学共振器の異なった共振周波数に
安定化する際に最大値制御を用いたが、第２の実施例に
おいては以下に述べる制御を用いている。すなわち、制
御装置２０内において、検波器１８の出力が最大になる
時刻と、光検波器１６の出力が最大になる時刻とを比較
する。FIG. 2 is a block diagram showing the configuration of a second embodiment of the present invention. In the embodiment shown in Fig. 1, maximum value control was used to stabilize the oscillation frequency of each laser device to a different resonance frequency of the optical resonator, but in the second embodiment, the control described below was used. is used. That is, within the control device 20, the time when the output of the detector 18 becomes maximum is compared with the time when the output of the photodetector 16 becomes maximum.
参照用レーザ１１の発振周波数は時間に対して掃引して
いるので、前記両時刻の差はレーザ装置１゜２．３の発
振周波数と、光学共振器１２の共振周波数との周波数差
を示すことになる。したがってカウンタ１９によって、
参照用レーザ１１の発振周波数の掃引と同期をとりなが
ら、制御装置２０から、レーザ周波数制御装置４．５．
６に両時刻の差が０になるよう制御信号を出力すること
で、レーザ装置１．２．３の発振周波数をそれぞれ光学
共振器の異なった共振周波数に安定化することができる
。Since the oscillation frequency of the reference laser 11 is swept over time, the difference between the two times indicates the frequency difference between the oscillation frequency of the laser device 1°2.3 and the resonant frequency of the optical resonator 12. become. Therefore, by the counter 19,
While synchronizing with the sweep of the oscillation frequency of the reference laser 11, the control device 20 controls the laser frequency control devices 4.5.
By outputting a control signal at 6 so that the difference between the two times becomes 0, the oscillation frequencies of the laser devices 1, 2, and 3 can be stabilized at different resonance frequencies of the optical resonators.
第２の実施例において、破線で囲った制御部以外は、第
１の実施例と同じ装置を用い、第１の実施例と同様の立
ち上げ時の手順を踏むことにより３台のレーザ装置１，
２．３の発振周波数間隔を１０ＧＨｚで一定に保つこと
ができた。In the second embodiment, the same equipment as in the first embodiment is used except for the control unit surrounded by the broken line, and three laser devices 1 are installed by following the same startup procedure as in the first embodiment. ，
The oscillation frequency interval of 2.3 was able to be kept constant at 10 GHz.
（発明の効果）
以上に述べてきたように、本発明によって任意の個数の
レーザ装置間の発振周波数間隔を同時に安定化すること
ができる。しかもその発振周波数間隔は光学共振器によ
って厳密に規定されており、また、光学共振器はその共
振周波数を掃引する必要がないので装置全体を小型化す
ることができる。(Effects of the Invention) As described above, according to the present invention, the oscillation frequency interval between any number of laser devices can be stabilized at the same time. Furthermore, the oscillation frequency interval is strictly defined by the optical resonator, and since the optical resonator does not need to sweep its resonant frequency, the entire device can be miniaturized.
また、制御対象たるレーザ装置にいかなる種類の変調が
かけられていても、発振周波数間隔を安定化することが
できる。Moreover, the oscillation frequency interval can be stabilized no matter what type of modulation is applied to the laser device to be controlled.
第１図は本発明の第１の実施例の構成を示すブロック図
、第２図は本発明の第２の実施例の構成を示すブロック
図である。
１．２．３・・・制御対象のレーザ装置、４，５゜６・
・・レーザ周波数制御装置、７．８．９・・・変調器、
１０・・・鋸歯状波発生装置、１１・・・参照用レーザ
装置、１２・・・光学共＠器、１３．１５・・・光合波
器、１４・・・光分波器、１６・・・光検出器、１７・
・・低域通過フィルタ、１８・・・検波器、１９・・・
カウンタ、２０・・・レーザ発振周波数制御装置。FIG. 1 is a block diagram showing the structure of a first embodiment of the invention, and FIG. 2 is a block diagram showing the structure of a second embodiment of the invention. 1.2.3... Laser device to be controlled, 4.5°6.
...Laser frequency control device, 7.8.9...Modulator,
DESCRIPTION OF SYMBOLS 10... Sawtooth wave generator, 11... Reference laser device, 12... Optical beam combiner, 13.15... Optical multiplexer, 14... Optical demultiplexer, 16...・Photodetector, 17・
...Low pass filter, 18...Detector, 19...
Counter, 20... Laser oscillation frequency control device.
Claims (1)
出射光を合波する第１の光合波器と、前記複数の発振周
波数間隔安定化対象レーザ装置の発振周波数を含む範囲
で発振周波数を掃引する参照用レーザ装置と、該参照用
レーザ装置の出射光を入射する光学共振器と、該光学共
振器の出射光と前記第１の光合波器の出射光とを合波す
る第２の光合波器と、該第２の光合波器の出力光を受光
して前記光学共振器を通過した前記参照用レーザ装置出
射光と前記複数の発振周波数間隔安定化対象レーザ装置
出射光のビードを検出する光検出器と、前記複数の発振
周波間隔安定化対象レーザ装置の発振周波数を前記光学
共振器の互いに異なった複数の共振周波数にそれぞれ安
定化させる制御信号を前記光検出器の出力に基づき生成
し、該発振周波数間隔安定化対象レーザ装置に供給する
レーザ周波数制御手段とを含んでなることを特徴とする
複数レーザ装置発振周波数間隔安定化装置。a first optical multiplexer that combines emitted light from a plurality of laser devices that are targets for oscillation frequency interval stabilization, and sweeps the oscillation frequency in a range that includes the oscillation frequencies of the plurality of laser devices that are targets for oscillation frequency interval stabilization. a reference laser device, an optical resonator into which the light emitted from the reference laser device enters, and a second optical combiner which combines the light emitted from the optical resonator and the light emitted from the first optical multiplexer. receiving the output light of the second optical multiplexer and detecting a bead of the reference laser device output light and the plurality of oscillation frequency interval stabilization target laser device output lights that have passed through the optical resonator; generates a control signal based on the output of the photodetector that stabilizes the oscillation frequency of the plurality of oscillation frequency interval stabilization target laser devices to a plurality of mutually different resonance frequencies of the optical resonator, respectively; 1. A device for stabilizing oscillation frequency intervals of a plurality of laser devices, comprising: a laser frequency control means for supplying the laser frequency to the laser device whose oscillation frequency intervals are to be stabilized.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63016191A JPH01189976A (en) | 1988-01-26 | 1988-01-26 | Oscillation frequency interval stabilizing device for plural lasers |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63016191A JPH01189976A (en) | 1988-01-26 | 1988-01-26 | Oscillation frequency interval stabilizing device for plural lasers |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH01189976A true JPH01189976A (en) | 1989-07-31 |
Family
ID=11909625
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63016191A Pending JPH01189976A (en) | 1988-01-26 | 1988-01-26 | Oscillation frequency interval stabilizing device for plural lasers |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH01189976A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7362925B2 (en) | 2001-12-28 | 2008-04-22 | Fujitsu Limited | Control method and control apparatus of optical device |
-
1988
- 1988-01-26 JP JP63016191A patent/JPH01189976A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7362925B2 (en) | 2001-12-28 | 2008-04-22 | Fujitsu Limited | Control method and control apparatus of optical device |
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