JPS62216284A - Drive circuit for semiconductor laser - Google Patents
Drive circuit for semiconductor laserInfo
- Publication number
- JPS62216284A JPS62216284A JP4564986A JP4564986A JPS62216284A JP S62216284 A JPS62216284 A JP S62216284A JP 4564986 A JP4564986 A JP 4564986A JP 4564986 A JP4564986 A JP 4564986A JP S62216284 A JPS62216284 A JP S62216284A
- Authority
- JP
- Japan
- Prior art keywords
- collector
- transistor
- semiconductor laser
- diode
- load
- 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
- 239000004065 semiconductor Substances 0.000 title claims abstract description 10
- 230000003287 optical effect Effects 0.000 abstract description 10
- 239000003990 capacitor Substances 0.000 abstract description 5
- 238000010586 diagram Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000001419 dependent effect Effects 0.000 description 1
Classifications
-
- 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
- H01S5/04—Processes or apparatus for excitation, e.g. pumping, e.g. by electron beams
- H01S5/042—Electrical excitation ; Circuits therefor
Landscapes
- Physics & Mathematics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Optics & Photonics (AREA)
- Semiconductor Lasers (AREA)
Abstract
Description
【発明の詳細な説明】
〔概要〕
カレントスイッチ形式を用いた半導体レーザ駆動回路に
おいて、半導体レーザに流れるパルス電流の変動による
光出力のパルス幅変動を解決するため、カレントスイッ
チの半導体レーザ接続側コレクタと異なる側のコレクタ
の負荷としてダイオード又はダイオード及びコンデンサ
を用いる事により、光出力のパルス幅変動を小さくする
ことが開示されている。[Detailed Description of the Invention] [Summary] In a semiconductor laser drive circuit using a current switch type, in order to solve the pulse width fluctuation of the optical output due to the fluctuation of the pulse current flowing through the semiconductor laser, the collector on the semiconductor laser connection side of the current switch is It has been disclosed that the pulse width fluctuation of the optical output can be reduced by using a diode or a diode and a capacitor as a load on the collector on the side different from the one shown in FIG.
本発明は、カレントスイッチ形式の半導体レーザ駆動回
路に関する。The present invention relates to a current switch type semiconductor laser drive circuit.
光通信等においては、光出力パルス幅を任意にかつ一定
の幅に保つ事が要求されるが、半導体レーザ（以下ＬＤ
と略す）の特性のバラツキ・温度変動に対して安定な回
路が要求される。In optical communications, etc., it is required to arbitrarily maintain the optical output pulse width at a constant width, but semiconductor lasers (hereinafter referred to as LDs)
A circuit that is stable against variations in characteristics and temperature fluctuations is required.
従来のカレントスイッチ形式のＬＤ駆動回路の回路図を
第２図に示す。図中の符号１はＬＤ、 ２はＬＤ直列
負荷抵抗、３は抵抗、４ないし６はトランジスタである
。A circuit diagram of a conventional current switch type LD drive circuit is shown in FIG. In the figure, reference numeral 1 is an LD, 2 is an LD series load resistance, 3 is a resistor, and 4 to 6 are transistors.
図示のように、カレントスイッチのＬＤ接続側と異なる
側のコレクタには、負荷として抵抗が用いられるか、電
源又はＧＮＤに直接接続されている。そして、トランジ
スタ４と５との夫々のペースに入力信号又は基準信号（
反転入力信号又は基準信号）を供給することによって、
■、Ｄ Ｉが駆動され１発光される。As shown in the figure, a resistor is used as a load on the collector of the current switch on the side different from the LD connection side, or the collector is directly connected to the power supply or GND. Then, the input signal or the reference signal (
by supplying an inverted input signal or a reference signal).
(2) DI is driven and one light is emitted.
第２図図示の従来のカレントスイッチ形式のＬＤ駆動回
路では、トランジスタ４．５のコレクタの負荷として抵
抗が用いられているために、駆動回路に流れるパルス電
流の振幅の変化によってトランジスタ４，５に流れる電
流１ａ、Ｉｂが変化し、コレクタ電位が変動する。従っ
て、コレクターエミッタ間電圧■。が変動する。トラン
ジスタ５のベースには、基準電圧Ｖ ｒａｆが印加され
ており、パルス電流の振幅■。との大小関係によりトラ
ンジスタ４．５がＯＮ、ＯＦＦする。In the conventional current switch type LD drive circuit shown in FIG. 2, a resistor is used as a load on the collector of the transistor 4.5, so changes in the amplitude of the pulse current flowing through the drive circuit cause the transistors 4 and 5 to The flowing currents 1a and Ib change, and the collector potential changes. Therefore, the collector-emitter voltage ■. changes. A reference voltage V raf is applied to the base of the transistor 5, and the amplitude of the pulse current is -. The transistor 4.5 is turned on or off depending on the magnitude relationship between the two.
即ち＋ Ｖ ｒｌｌｆ ＜Ｖ ００時トランジスタ４
には電流が流れ、トランジスタ５はＯＦＦとなりＶ ｒ
ａｆ〉■。の場合は逆である。前述したように、ｖ。That is, when +V rllf <V 00, transistor 4
A current flows through V r , transistor 5 is turned off, and V r
af〉■. The opposite is true for . As mentioned above, v.
の変化により＋ＶＣＩが変動するため■。の基準レベル
が変動してしまい、■、。、と■。との大小関係が一定
ではなくなる。このために、ＬＤ特性及び光出力パワー
によってパルス電流の振幅が異なることとなる場合、コ
レクタの負荷の抵抗値をそれに応じて調整して、ｖｃｌ
ｌを一定にする必要があった。また温度変動によりパル
ス電流が変化した場合、これに伴い光出力のパルス幅が
変動してしまうという問題があった。■ Because +VCI fluctuates due to changes in . The reference level of has fluctuated, ■. , and■. The size relationship between the two will no longer be constant. For this reason, if the amplitude of the pulse current differs depending on the LD characteristics and optical output power, the resistance value of the collector load is adjusted accordingly, and the vcl
It was necessary to keep l constant. Furthermore, when the pulse current changes due to temperature fluctuations, there is a problem in that the pulse width of the optical output changes accordingly.
本発明のＬ Ｄ駆動回路は、カレントスイッチ形式の回
路において、少なくとも、ＬＤの接続されるコレクタと
異なる側のコレクタの負荷として。The LD drive circuit of the present invention is used as a load of at least a collector on a side different from the collector connected to the LD in a current switch type circuit.
ダイオード、又はダイオードとコンデンサとの組合わせ
回路を用いるようにしている。A diode or a combination circuit of a diode and a capacitor is used.
本発明の場合、コレクタ負荷には、ダイオードを含む回
路で構成されているためにコレクタの電位がいわば所定
レベルに保たれ、パルス電流の大きさに依存することな
くトランジスタのＶｏが一定に保たれる。このため、パ
ルス電流変動によるトランジスタの周波数特性の変動が
抑えられ、これに起因する光出力波形の変動を抑える事
ができる。In the case of the present invention, since the collector load is composed of a circuit including a diode, the potential of the collector is maintained at a predetermined level, so that Vo of the transistor is kept constant regardless of the magnitude of the pulse current. It will be done. Therefore, fluctuations in the frequency characteristics of the transistor due to fluctuations in the pulse current can be suppressed, and fluctuations in the optical output waveform caused by this can be suppressed.
第１図は本発明の一実施例を示す。図中の符号１はＬＤ
、２は抵抗、４ないし６はトランジスタ。FIG. 1 shows an embodiment of the invention. Code 1 in the diagram is LD
, 2 is a resistor, and 4 to 6 are transistors.
７はダイオード、８はバイパス・コンデンサである。7 is a diode, and 8 is a bypass capacitor.
図示の場合には、パルス電流の振幅の如何に拘らず（即
ち、電流ｘａ′、ｒｂ′の値にかかわらず）トランジス
タ４のＶＣｆｉを一定にする事ができ、■。In the illustrated case, the VCfi of the transistor 4 can be kept constant regardless of the amplitude of the pulse current (that is, regardless of the values of the currents xa' and rb').
の基準レベルは一定となり、光出力波形のパルス電流依
存性を少なくする事ができる。The reference level becomes constant, and the dependence of the optical output waveform on the pulse current can be reduced.
なお、第１図において、抵抗２の代わりにダイオードを
用いてトランジスタ５のコレクタ電位を一定に保つこと
も考慮される。しかし発明者の実験によれば、第１図図
示の構成の下でも十分に実用性をもっていることが確か
められた。Note that in FIG. 1, it is also possible to use a diode instead of the resistor 2 to keep the collector potential of the transistor 5 constant. However, according to the inventor's experiments, it has been confirmed that even the configuration shown in FIG. 1 has sufficient practicality.
以上説明した如く２本発明によれば、ＬＤのパルス電流
量に依存することの少ない光出力波形を得る事ができる
。そして、パルス幅を一定に保つことが可能となる。As explained above, according to the two aspects of the present invention, it is possible to obtain an optical output waveform that is less dependent on the amount of pulse current of the LD. Then, it becomes possible to keep the pulse width constant.
第１図は本発明の一実施例構成、第２図は従来の構成を
示す。
図中、１は半導体レーザ、４，５．６は夫々トランジス
タ、７はダイオード、８はバイパス・コンデンサを表す
。FIG. 1 shows a configuration of an embodiment of the present invention, and FIG. 2 shows a conventional configuration. In the figure, 1 is a semiconductor laser, 4, 5.6 are transistors, 7 is a diode, and 8 is a bypass capacitor.
Claims (1)
）のコレクタの負荷として少なくとも半導体レーザ（１
）を接続すると共に、 上記カレントスイッチを構成する他方のトランジスタ（
４）のコレクタに負荷として少なくともダイオード（７
）が用いられている ことを特徴とする半導体レーザ駆動回路。[Claims] One transistor (5
) as a load on the collector of at least a semiconductor laser (1
) and connect the other transistor (
At least a diode (7) is installed as a load on the collector of 4).
) is used.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4564986A JPS62216284A (en) | 1986-03-03 | 1986-03-03 | Drive circuit for semiconductor laser |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4564986A JPS62216284A (en) | 1986-03-03 | 1986-03-03 | Drive circuit for semiconductor laser |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS62216284A true JPS62216284A (en) | 1987-09-22 |
Family
ID=12725220
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4564986A Pending JPS62216284A (en) | 1986-03-03 | 1986-03-03 | Drive circuit for semiconductor laser |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS62216284A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1261129A1 (en) * | 2001-05-25 | 2002-11-27 | Agilent Technologies, Inc. (a Delaware corporation) | Amplifier apparatus for an output stage of a laser driver circuit |
| JP2016103640A (en) * | 2014-11-28 | 2016-06-02 | 住友電気工業株式会社 | Laser drive circuit |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS589444A (en) * | 1981-07-08 | 1983-01-19 | Nippon Kogaku Kk <Nikon> | Driving circuit of light emitting element |
-
1986
- 1986-03-03 JP JP4564986A patent/JPS62216284A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS589444A (en) * | 1981-07-08 | 1983-01-19 | Nippon Kogaku Kk <Nikon> | Driving circuit of light emitting element |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1261129A1 (en) * | 2001-05-25 | 2002-11-27 | Agilent Technologies, Inc. (a Delaware corporation) | Amplifier apparatus for an output stage of a laser driver circuit |
| US6650183B2 (en) | 2001-05-25 | 2003-11-18 | Agilent Technologies, Inc. | Amplifier apparatus for an output stage of a laser driver circuit |
| JP2016103640A (en) * | 2014-11-28 | 2016-06-02 | 住友電気工業株式会社 | Laser drive circuit |
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