JPH04102381A - Driving circuit of semiconductor laser - Google Patents

Driving circuit of semiconductor laser

Info

Publication number
JPH04102381A
JPH04102381A JP22181890A JP22181890A JPH04102381A JP H04102381 A JPH04102381 A JP H04102381A JP 22181890 A JP22181890 A JP 22181890A JP 22181890 A JP22181890 A JP 22181890A JP H04102381 A JPH04102381 A JP H04102381A
Authority
JP
Japan
Prior art keywords
semiconductor laser
capacitor
laser
current
driving
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
Application number
JP22181890A
Other languages
Japanese (ja)
Inventor
Hiroshi Takegawa
浩 竹川
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sharp Corp
Original Assignee
Sharp Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Sharp Corp filed Critical Sharp Corp
Priority to JP22181890A priority Critical patent/JPH04102381A/en
Publication of JPH04102381A publication Critical patent/JPH04102381A/en
Pending legal-status Critical Current

Links

Abstract

PURPOSE:To acquire a driving circuit which hardly generates resonance and hardly generates back electromotive force at ON/OFF time of a driving current by supplying power through a load resistance and a capacitor. CONSTITUTION:A laser driver includes a load resistor R connected at its one end to one end of a semiconductor laser 3, and a capacitor C connected between the other end of the semiconductor laser 3 and the other end of the resistor R, and power is supplied across the capacitor C to the laser 3. Therefore, a surge current flowing into the laser 3 is limited to a small value by the resistance R and a most part of a surge current excepting a current which flows into the laser 3 is charged to the capacitor C. Thereby, unstable light output can be restrained by a surge current. Furthermore, a semiconductor laser driving circuit can be realized, which does not require inductance, hardly generates resonance even if driving conditions change, restrains variation of light output, and restrains generation of back electromotive force at ON/OFF time of a driving current.

Description

【発明の詳細な説明】[Detailed description of the invention] 【産業上の利用分野】[Industrial application field]

本発明は、半導体レーザを用いた情報処理機器や半導体
レーザのテスタに用いられる半導体レーザの駆動回路に
関する。
The present invention relates to a semiconductor laser drive circuit used in information processing equipment using semiconductor lasers and semiconductor laser testers.

【従来の技術】[Conventional technology]

従来、半導体レーザの駆動回路は、第3図(a)および
(b)に示すような、インダクタンス12や14および
コンデンサ11や15からなるローパスフィルタを備え
ている。上記半導体レーザの駆動回路は、上記ローパス
フィルタを介して半導体レーザ13や16に電力を供給
することにより、上記電力の高周波成分をカットして、
上記半導体レーザ13や16にサージ電流が流れ込むこ
とを防止している。
Conventionally, a semiconductor laser drive circuit includes a low-pass filter consisting of inductances 12 and 14 and capacitors 11 and 15 as shown in FIGS. 3(a) and 3(b). The driving circuit for the semiconductor laser cuts the high frequency component of the power by supplying power to the semiconductor lasers 13 and 16 through the low-pass filter.
This prevents surge current from flowing into the semiconductor lasers 13 and 16.

【発明が解決しようとする課題】[Problem to be solved by the invention]

一般に、測定器および製造装置において半導体レーザを
駆動する場合、駆動回路部と半導体レーザ素子との間の
配線距離が長くなる傾向がある。 このため、上記配線に対するノイズの誘導や上記配線の
持つインダクタンスやキャパンタンスや抵抗の影響が大
きくなり、無視てきなくなる。 ところで、上記従来の半導体レーザの駆動回路は、上記
ローパスフィルタを構成しているインダクタンス12.
14およびコンデンサ11.15のキャバンタンスの値
によっては、共振を起こし易くなり、この共振が上記半
導体レーザ13.+ 6の光出力を、不安定にするとい
う問題がある。例えば、パルス駆動の場合には、上記半
導体レーザの光出力は、第4図に示すように振動し、不
安定になる。 また、上記半導体レーザの駆動回路が上記半導体レーザ
13.+6に流す駆動電流をオン・オフする際に、上記
半導体レーザの駆動回路のローパスフィルタが有するイ
ンダクタンス12.14が逆起電力を発生して、上記半
導体レーザ13.16を破壊する可能性があるという問
題がある。そして、上記インダクタンス12.14に流
れる電流の大きさに比例して、上記逆起電力が大きくな
るので、上記半導体レーザI 3.16を大電流で駆動
する場合には、上記逆起電力が上記半導体レーザI 3
,16を破壊し易すく、特に問題となる。 そこで、本発明の目的は、共振が発生しにくくて、かつ
駆動電流のオン・オフ時に逆起電力が発生しにくい半導
体レーザの駆動回路を提供することにある。
Generally, when driving a semiconductor laser in a measuring instrument or a manufacturing device, the wiring distance between the drive circuit section and the semiconductor laser element tends to become long. Therefore, the effects of noise induction on the wiring and the inductance, capantance, and resistance of the wiring become so great that they cannot be ignored. By the way, the conventional semiconductor laser drive circuit described above has an inductance 12.
Depending on the value of the cavantance of the semiconductor laser 13. There is a problem that the optical output of +6 becomes unstable. For example, in the case of pulse driving, the optical output of the semiconductor laser oscillates and becomes unstable as shown in FIG. Further, the driving circuit for the semiconductor laser is the semiconductor laser 13. When turning on and off the drive current flowing through +6, the inductance 12.14 of the low-pass filter of the drive circuit of the semiconductor laser generates a back electromotive force, which may destroy the semiconductor laser 13.16. There is a problem. Since the back electromotive force increases in proportion to the magnitude of the current flowing through the inductance 12.14, when driving the semiconductor laser I 3.16 with a large current, the back electromotive force increases as described above. Semiconductor laser I 3
, 16, which is particularly problematic. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a semiconductor laser drive circuit in which resonance is less likely to occur and back electromotive force is less likely to be generated when the drive current is turned on and off.

【課題を解決するための手段】 上記目的を達成するため、本発明の半導体レーザの駆動
回路は、一端を半導体レーザの一端に接続した負荷抵抗
と、上記半導体レーザの他端と上記負荷抵抗の他端とに
両端を接続したコンデンサを備えて、上記コンデンサの
両端から電力を供給することを特徴としている。
[Means for Solving the Problems] In order to achieve the above object, a semiconductor laser drive circuit of the present invention includes a load resistor having one end connected to one end of the semiconductor laser, and a load resistor connected to the other end of the semiconductor laser and the load resistor. The device is characterized in that it includes a capacitor whose both ends are connected to the other end, and power is supplied from both ends of the capacitor.

【作用】[Effect]

半導体レーザに流れ込もうとするサージ電流は、抵抗に
よって小さい値に制限されて、上記半導体レーザに流れ
込む。そして、上記半導体レーザに流れ込む電流以外の
大部分のサージ電流はコンデンサに充電される。したが
って、上記サージ電流によって、上記半導体レーザの光
出力か不安定になることが抑えられる。また、インダク
タンスを用いていないので、上記半導体レーザの駆動条
件が変動しても共振が発生しにくく、上記半導体レーザ
の光出力の変動が抑えられる。また、インダクタンスを
用いていないので、上記半導体レーザへの駆動電流のオ
ン・オフ時に、逆起電力が発生することが抑えられ、上
記逆起電力が半導体レーザを破壊することが抑えられる
A surge current that attempts to flow into the semiconductor laser is limited to a small value by the resistor, and then flows into the semiconductor laser. Most of the surge current other than the current flowing into the semiconductor laser is charged into the capacitor. Therefore, the optical output of the semiconductor laser is prevented from becoming unstable due to the surge current. Further, since no inductance is used, resonance is less likely to occur even if the driving conditions of the semiconductor laser vary, and fluctuations in the optical output of the semiconductor laser can be suppressed. Further, since no inductance is used, generation of back electromotive force is suppressed when the drive current to the semiconductor laser is turned on and off, and the back electromotive force is suppressed from destroying the semiconductor laser.

【実施例】【Example】

以下、本発明を図示の実施例により詳細に説明する。 第1図は本実施例の半導体レーザの駆動回路の回路図で
ある。第1図に示すように、上記実施例は半導体レーザ
3と直列に5〜50Ω程度の抵抗2を接続している。そ
して、上記半導体レーザ3と上記抵抗2に対して並列に
0.001μF〜01tIFのキヤパシタンスを有する
コンデンサIを接続している。ここで、電磁誘導の影響
を避ける1こめに、上記半導体レーザ3と上記抵抗2と
の距離および上記半導体レーザ3と上記コンデンサIと
の距離は、数10cz以内にすることが望ましい。 上記実施例において、半導体レーザ3に流れ込もうとす
るサージ電流は、上記抵抗2によって小さい値に制限さ
れて、上記半導体レーザ3に流れ込む。そして、上記半
導体レーザ3に流れ込む電流以外の大部分のサージ電流
は、上記コンデンサ1に流れ込み、上記コンデンサlを
充電する。したかって、上記サージ電流が上記半導体レ
ーザ3の光出力を不安定にすることを抑えることができ
る。 そして、例えば上記半導体レーザ3をパルス駆動する場
合には、第2図に示すように、上記半導体レーザ3の光
出力は立ち上かり波形かなまり、上昇に要する時間か長
くなる。また、上記実施例では、インダクタンスを用い
ていないので、上記半導体レーザ3の駆動条件の変動に
よる共振を抑えることかでき、上記半導体レーザ3の先
出力の変動を抑えることができる。したがって、例えば
半導体レーザ3をパルス駆動する場合、第2図に示すよ
うに、上記半導体レーザ3の光出力は安定し、振動しな
い。また、上記実施例では、インダクタンスを用いてい
ないので、上記半導体レーザ3への駆動電流のオン・オ
フ時に逆起電力が発生することを抑えることができ、上
記逆起電力が上記半導体レーザ3を破壊することを抑え
ることができる。 また、上記抵抗2と上記コンデンサlの両方あるいは一
方を上記半導体レーザ3のチップ上に作製した場合には
、回路構成を簡単にできると共に上記半導体レーザ3の
光出力を特に安定化できる。
Hereinafter, the present invention will be explained in detail with reference to illustrated embodiments. FIG. 1 is a circuit diagram of a semiconductor laser drive circuit according to this embodiment. As shown in FIG. 1, in the above embodiment, a resistor 2 of about 5 to 50 ohms is connected in series with the semiconductor laser 3. A capacitor I having a capacitance of 0.001 .mu.F to 0.01 tIF is connected in parallel to the semiconductor laser 3 and the resistor 2. Here, in order to avoid the influence of electromagnetic induction, it is desirable that the distance between the semiconductor laser 3 and the resistor 2 and the distance between the semiconductor laser 3 and the capacitor I be within several tens of cz. In the embodiment described above, the surge current that attempts to flow into the semiconductor laser 3 is limited to a small value by the resistor 2, and then flows into the semiconductor laser 3. Most of the surge current other than the current flowing into the semiconductor laser 3 flows into the capacitor 1 and charges the capacitor l. Therefore, it is possible to prevent the surge current from making the optical output of the semiconductor laser 3 unstable. For example, when the semiconductor laser 3 is pulse-driven, as shown in FIG. 2, the optical output of the semiconductor laser 3 has a short rising waveform, and the time required for the rising waveform becomes long. Further, in the above embodiment, since no inductance is used, resonance due to fluctuations in the driving conditions of the semiconductor laser 3 can be suppressed, and fluctuations in the prior output of the semiconductor laser 3 can be suppressed. Therefore, for example, when the semiconductor laser 3 is pulse-driven, the optical output of the semiconductor laser 3 is stable and does not oscillate, as shown in FIG. Further, in the above embodiment, since no inductance is used, it is possible to suppress generation of back electromotive force when the drive current to the semiconductor laser 3 is turned on and off. Destruction can be prevented. Further, when both or one of the resistor 2 and the capacitor l are fabricated on the chip of the semiconductor laser 3, the circuit configuration can be simplified and the optical output of the semiconductor laser 3 can be particularly stabilized.

【発明の効果】【Effect of the invention】

以上の説明より明らかなように、本発明の半導体レーザ
の駆動回路は、サージ電流を小さい値に制限して半導体
レーザに流すので、上記サージ電流が上記半導体レーザ
の光出力を不安定にするのを抑えることができる。また
、この駆動回路はインダクタンスを用いていないので、
共振が発生しにくく、半導体レーザの光出力を安定化で
きる。 また、上記駆動回路はインダクタンスを用いていないの
で、上記駆動回路の駆動電流のオン・オフ時に逆起電力
が発生することを抑えることができ、上記逆起電力が半
導体レーザを破壊することを抑えることができる。
As is clear from the above explanation, since the semiconductor laser drive circuit of the present invention limits the surge current to a small value and allows it to flow through the semiconductor laser, the surge current does not destabilize the optical output of the semiconductor laser. can be suppressed. Also, since this drive circuit does not use inductance,
Resonance is less likely to occur and the optical output of the semiconductor laser can be stabilized. Furthermore, since the drive circuit does not use inductance, it is possible to suppress the generation of back electromotive force when the drive current of the drive circuit is turned on and off, and to suppress the back electromotive force from destroying the semiconductor laser. be able to.

【図面の簡単な説明】[Brief explanation of drawings]

第1図は本発明の半導体レーザの駆動回路の一実施例の
回路図、第2図は上記実施例を用いた半導体レーザの光
出力特性図、第3図は従来の半導体レーザの駆動回路、
第4図は従来の半導体レーザの駆動回路を用L)た半導
体レーザの光出力特性図である。 1.11.15  コンデンサ、 2・・抵抗、3.1
3.16・・・半導体レーザ、 12.14・・・インダクタンス。
FIG. 1 is a circuit diagram of an embodiment of a semiconductor laser drive circuit of the present invention, FIG. 2 is a diagram of optical output characteristics of a semiconductor laser using the above embodiment, and FIG. 3 is a conventional semiconductor laser drive circuit.
FIG. 4 is an optical output characteristic diagram of a semiconductor laser using a conventional semiconductor laser drive circuit. 1.11.15 Capacitor, 2...Resistance, 3.1
3.16... Semiconductor laser, 12.14... Inductance.

Claims (1)

【特許請求の範囲】[Claims] (1)一端を半導体レーザの一端に接続した負荷抵抗と
、 上記半導体レーザの他端と上記負荷抵抗の他端とに両端
を接続したコンデンサを備えて、 上記コンデンサの両端から電力を供給することを特徴と
する半導体レーザの駆動回路。
(1) A load resistor having one end connected to one end of the semiconductor laser, and a capacitor having both ends connected to the other end of the semiconductor laser and the other end of the load resistor, and power is supplied from both ends of the capacitor. A semiconductor laser drive circuit featuring:
JP22181890A 1990-08-21 1990-08-21 Driving circuit of semiconductor laser Pending JPH04102381A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP22181890A JPH04102381A (en) 1990-08-21 1990-08-21 Driving circuit of semiconductor laser

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP22181890A JPH04102381A (en) 1990-08-21 1990-08-21 Driving circuit of semiconductor laser

Publications (1)

Publication Number Publication Date
JPH04102381A true JPH04102381A (en) 1992-04-03

Family

ID=16772674

Family Applications (1)

Application Number Title Priority Date Filing Date
JP22181890A Pending JPH04102381A (en) 1990-08-21 1990-08-21 Driving circuit of semiconductor laser

Country Status (1)

Country Link
JP (1) JPH04102381A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2016021458A (en) * 2014-07-14 2016-02-04 住友電気工業株式会社 Driver circuit and optical communication device including the same
JP2016096221A (en) * 2014-11-13 2016-05-26 住友電気工業株式会社 Drive circuit

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61107783A (en) * 1984-10-30 1986-05-26 Matsushita Electric Ind Co Ltd Semiconductor laser device
JPS61107785A (en) * 1984-10-30 1986-05-26 Matsushita Electric Ind Co Ltd Semiconductor laser device
JPH0218978A (en) * 1988-07-07 1990-01-23 Sumitomo Electric Ind Ltd Driving circuit for semiconductor laser

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61107783A (en) * 1984-10-30 1986-05-26 Matsushita Electric Ind Co Ltd Semiconductor laser device
JPS61107785A (en) * 1984-10-30 1986-05-26 Matsushita Electric Ind Co Ltd Semiconductor laser device
JPH0218978A (en) * 1988-07-07 1990-01-23 Sumitomo Electric Ind Ltd Driving circuit for semiconductor laser

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2016021458A (en) * 2014-07-14 2016-02-04 住友電気工業株式会社 Driver circuit and optical communication device including the same
JP2016096221A (en) * 2014-11-13 2016-05-26 住友電気工業株式会社 Drive circuit

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