JPH04293326A - Optical transmitter - Google Patents
Optical transmitterInfo
- Publication number
- JPH04293326A JPH04293326A JP3057547A JP5754791A JPH04293326A JP H04293326 A JPH04293326 A JP H04293326A JP 3057547 A JP3057547 A JP 3057547A JP 5754791 A JP5754791 A JP 5754791A JP H04293326 A JPH04293326 A JP H04293326A
- Authority
- JP
- Japan
- Prior art keywords
- signal
- emitting element
- level
- circuit
- light emitting
- 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
- 230000003287 optical effect Effects 0.000 title claims description 22
- 230000000087 stabilizing effect Effects 0.000 claims abstract description 16
- 238000006243 chemical reaction Methods 0.000 claims 1
- 230000006641 stabilisation Effects 0.000 description 6
- 238000011105 stabilization Methods 0.000 description 6
- 238000010586 diagram Methods 0.000 description 5
- 230000005540 biological transmission Effects 0.000 description 3
- 238000004891 communication Methods 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
Landscapes
- Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
- Optical Communication System (AREA)
Abstract
Description
【０００１】0001
【産業上の利用分野】本発明は光通信システムに用いる
光送信器に関し、特にシステムの監視制御信号伝送用の
アナログ副信号をディジタル主信号に重畳し光信号に変
換して送出する光送信器に関する。[Industrial Application Field] The present invention relates to an optical transmitter used in an optical communication system, and more particularly to an optical transmitter that superimposes an analog sub-signal for transmitting system monitoring and control signals onto a digital main signal, converts it into an optical signal, and transmits the optical signal. Regarding.
【０００２】0002
【従来の技術】最近の光通信システムにおいては、シス
テムの保守に必要な監視制御信号を伝送するためにアナ
ログ副信号を使用し、振幅変調方式によりこれをディジ
タル主信号に重畳して伝送する場合が多くなっている。[Background Art] In recent optical communication systems, analog sub-signals are used to transmit supervisory control signals necessary for system maintenance, and these are superimposed on digital main signals using an amplitude modulation method for transmission. are increasing.
【０００３】従来、この種伝送方式の光送信器として図
２に示すものがある。図２は従来例の（ａ）回路構成を
示すブロック図、（ｂ）動作を説明するタイムチャ―ト
である。図２（ａ）において、監視制御用のアナログ副
信号１０１は変調波安定化回路４に入力され、ここでレ
ベルが安定化されその出力信号１０２が発光素子駆動回
路１に加えられる。発光素子駆動回路１はディジタル主
信号を入力し、これをレベル安定化されたアナログ副信
号で振副変調する。この変調出力信号、即ちアナログ副
信号を重畳したディジタル主信号はレベルアップされた
後、発光素子の駆動電流として光モジュ―ル２へ出力さ
れる。光モジュ―ル２はこれを光信号に変換し伝送路に
送出する。[0003] Conventionally, there is an optical transmitter of this type of transmission system as shown in FIG. FIG. 2 shows (a) a block diagram showing the circuit configuration of a conventional example, and (b) a time chart explaining the operation. In FIG. 2A, an analog sub-signal 101 for supervisory control is input to a modulated wave stabilization circuit 4, the level of which is stabilized there, and its output signal 102 is applied to the light emitting element drive circuit 1. The light emitting element driving circuit 1 receives a digital main signal and sub-modulates it with a level-stabilized analog sub-signal. This modulated output signal, ie, the digital main signal superimposed with the analog sub-signal, is leveled up and then output to the optical module 2 as a drive current for the light emitting element. The optical module 2 converts this into an optical signal and sends it to the transmission line.
【０００４】尚、変調波安定化回路４は、アナログ副信
号が無入力の時は利得が最大となっており、アナログ副
信号が入力されると利得が下がり、その出力レベルを一
定として発光素子駆動回路１の変調器が過変調にならな
いようにしている。[0004] The modulated wave stabilizing circuit 4 has a maximum gain when no analog sub-signal is input, and when an analog sub-signal is input, the gain decreases and the output level is kept constant and the light emitting element The modulator of the drive circuit 1 is prevented from overmodulating.
【０００５】[0005]
【発明が解決しようとする課題】以上説明した従来例の
光送出器は、変調波安定化回路４の利得可変が若干の応
答時間を有するので、無入力時の最大状態から入力があ
った時の利得低下までに若干の時間を要する。図２（ｂ
）はこの動作を説明する図である。即ち、変調波安定化
回路３の出力１０２は、この立ち上りの瞬間ピ―クが発
生し、このピ―ク値が発光素子駆動回路１の過変調限界
を越えるとディジタル主信号に瞬間影響を与え、エラ―
が発生するという心配があった。[Problems to be Solved by the Invention] In the conventional optical transmitter described above, the variable gain of the modulated wave stabilizing circuit 4 has a slight response time, so when there is an input from the maximum state when there is no input, It takes some time for the gain to decrease. Figure 2(b)
) is a diagram explaining this operation. That is, the output 102 of the modulated wave stabilizing circuit 3 has an instantaneous peak at this rising edge, and when this peak value exceeds the overmodulation limit of the light emitting element driving circuit 1, it instantaneously affects the digital main signal. , error
There were concerns that this would occur.
【０００６】[0006]
【課題を解決するための手段】本発明の光送信器は、デ
ィジタル主信号をアナログ副信号で振幅変調しこの変調
出力を発光素子の駆動用信号として出力する発光素子駆
動回路と、前記駆動用信号を受けこれを光信号に変換し
ファイバ―に結合する前記発光素子を収容した光モジュ
―ルと、前記発光素子駆動回路への前記アナログ副信号
入力レベルを安定化する変調度安定化回路とから構成し
た光送信器において、前記変調度安定化回路は前記アナ
ログ副信号を入力し一定レベルに安定化して前記発光素
子駆動回路へ出力するレベル安定化増幅器と、前記アナ
ログ副信号を入力しその信号の有無を判定する入力判定
回路と、前記入力判定回路の出力信号を入力し前記レベ
ル安定化増幅器の利得を制御する利得制御器とから構成
されている。[Means for Solving the Problems] The optical transmitter of the present invention includes a light-emitting element drive circuit that amplitude-modulates a digital main signal with an analog sub-signal and outputs the modulated output as a driving signal for a light-emitting element; an optical module housing the light emitting element that receives a signal, converts it into an optical signal, and couples it to a fiber; and a modulation degree stabilization circuit that stabilizes the analog sub-signal input level to the light emitting element drive circuit. In the optical transmitter, the modulation degree stabilizing circuit includes a level stabilizing amplifier that inputs the analog sub-signal, stabilizes it at a constant level, and outputs it to the light emitting element drive circuit; It is comprised of an input determination circuit that determines the presence or absence of a signal, and a gain controller that receives the output signal of the input determination circuit and controls the gain of the level stabilizing amplifier.
【０００７】[0007]
【実施例】次に本発明の実施例を図を参照し説明する。
図１は本実施例の（ａ）回路構成を示すブロック図、（
ｂ）動作を説明するタイムチャ―トである。Embodiments Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the (a) circuit configuration of this embodiment;
b) A time chart explaining the operation.
【０００８】図１（ａ）において、アナログ副信号は変
調安定回路３に入りレベル安定化増幅器３１で一定レベ
ルに制御安定化され発光素子駆動回路１へ出力される。
入力アナログ副信号の一部は入力判定回路３３へ入り、
ここで所定のスレッシュレベルによる入力の有無判定を
行いその判定信号を利得制御器３２へ出力する。利得制
御器３２は判定信号が無の時、レベル安定化増幅器３１
の利得を最小に押え、判定信号が有に変った時、例えば
或る固定利得に一定時間保持した後、フリ―となるよう
な制御信号１０３を出力する。In FIG. 1A, the analog sub-signal enters the modulation stabilization circuit 3, is controlled and stabilized to a constant level by the level stabilization amplifier 31, and is output to the light emitting element drive circuit 1. A part of the input analog sub-signal enters the input determination circuit 33,
Here, the presence or absence of input is determined based on a predetermined threshold level, and the determination signal is output to the gain controller 32. The gain controller 32 controls the level stabilizing amplifier 31 when there is no determination signal.
The control signal 103 is held to a minimum, and when the determination signal changes to "Yes", a control signal 103 is output that becomes free after being held at a certain fixed gain for a certain period of time, for example.
【０００９】この場合の一定時間とはレベル安定化増幅
器３１の入力に対する応答時間、即ち従来例で説明した
ピ―クの発生する時間をカバ―する時間をいう。この動
作は図１（ｂ）で説明してある。即ち、レベル安定化増
幅器３１の出力１０２は、アナログ副信号１０１の入力
が無から有に変った時、一定時間過変調にならない領域
の或る固定出力に押えられて後、通常の制御安定出力レ
ベルとなる。The fixed time in this case refers to the response time to the input of the level stabilizing amplifier 31, that is, the time that covers the time when the peak occurs as described in the conventional example. This operation is illustrated in FIG. 1(b). That is, when the input of the analog sub-signal 101 changes from nothing to present, the output 102 of the level stabilizing amplifier 31 is held down to a certain fixed output in a region where overmodulation does not occur for a certain period of time, and then returns to the normal control stable output. level.
【００１０】尚、発光素子駆動回路１と光モジュ―ル２
は従来例と同じものである。Note that the light emitting element driving circuit 1 and the optical module 2
is the same as the conventional example.
【００１１】[0011]
【発明の効果】以上説明したように本発明の光送出器は
、アナログ副信号の入力が無から有に変った瞬間のレベ
ル安定化増幅器３１の出力レベルのピ―クは押えられる
ので、発光素子駆動回路１の変調器は過変調せず、従っ
てこれに原因するディジタル主信号のエラ―は発生しな
いという効果がある。As explained above, in the optical transmitter of the present invention, the peak of the output level of the level stabilizing amplifier 31 at the moment when the input of the analog sub-signal changes from no to present is suppressed. The modulator of the element drive circuit 1 does not overmodulate, and therefore, there is an effect that errors in the digital main signal due to this do not occur.
【図面の簡単な説明】[Brief explanation of drawings]
【図１】本実施例の（ａ）回路構成を示すブロック図、
（ｂ）動作を説明するタイムチャ―トである。FIG. 1 is a block diagram showing the (a) circuit configuration of this embodiment;
(b) It is a time chart explaining the operation.
【図２】従来例の（ａ）回路構成を示すブロック図、（
ｂ）動作を説明するタイムチャ―トである。FIG. 2 is a block diagram showing the circuit configuration of the conventional example (a).
b) A time chart explaining the operation.
１ 発光素子駆動回路 ２ 光モジュ―ル ３，４ 変調度安定化回路 ３１ レベル安定化増幅器 ３２ 利得制御器 ３３ 入力判定回路 1 Light emitting element drive circuit 2. Optical module 3, 4 Modulation degree stabilization circuit 31 Level stabilization amplifier 32 Gain controller 33 Input judgment circuit
Claims (1)
振幅変調しこの変調出力を発光素子の駆動用信号として
出力する発光素子駆動回路と、前記駆動用信号を受けこ
れを光信号に変換しファイバ―に結合する前記発光素子
を収容した光モジュ―ルと、前記発光素子駆動回路への
前記アナログ副信号入力レベルを安定化する変調度安定
化回路とから構成した光送信器において、前記変調度安
定化回路は前記アナログ副信号を入力し一定レベルに安
定化して前記発光素子駆動回路へ出力するレベル安定化
増幅器と、前記アナログ副信号を入力しその信号の有無
を判定する入力判定回路と、前記入力判定回路の出力信
号を入力し前記レベル安定化増幅器の利得を制御する利
得制御器とから構成したことを特徴とする光送信器。1. A light-emitting element drive circuit that amplitude-modulates a digital main signal with an analog sub-signal and outputs the modulated output as a driving signal for a light-emitting element; an optical transmitter comprising an optical module housing the light emitting element coupled to the light emitting element; and a modulation degree stabilizing circuit that stabilizes the analog sub signal input level to the light emitting element drive circuit. The conversion circuit includes a level stabilizing amplifier that inputs the analog sub-signal, stabilizes it at a constant level, and outputs it to the light emitting element drive circuit; an input determination circuit that inputs the analog sub-signal and determines the presence or absence of the signal; 1. An optical transmitter comprising: a gain controller that receives an output signal from an input determination circuit and controls the gain of the level stabilizing amplifier.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3057547A JPH04293326A (en) | 1991-03-22 | 1991-03-22 | Optical transmitter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3057547A JPH04293326A (en) | 1991-03-22 | 1991-03-22 | Optical transmitter |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH04293326A true JPH04293326A (en) | 1992-10-16 |
Family
ID=13058812
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3057547A Pending JPH04293326A (en) | 1991-03-22 | 1991-03-22 | Optical transmitter |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH04293326A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5483373A (en) * | 1993-06-11 | 1996-01-09 | Alcatel N.V. | Optical transmitter for the common transmission of analog signals and digital qam signals |
-
1991
- 1991-03-22 JP JP3057547A patent/JPH04293326A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5483373A (en) * | 1993-06-11 | 1996-01-09 | Alcatel N.V. | Optical transmitter for the common transmission of analog signals and digital qam signals |
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