JPS62219680A - Constant-output drive circuit for semiconductor laser - Google Patents
Constant-output drive circuit for semiconductor laserInfo
- Publication number
- JPS62219680A JPS62219680A JP6059586A JP6059586A JPS62219680A JP S62219680 A JPS62219680 A JP S62219680A JP 6059586 A JP6059586 A JP 6059586A JP 6059586 A JP6059586 A JP 6059586A JP S62219680 A JPS62219680 A JP S62219680A
- Authority
- JP
- Japan
- Prior art keywords
- semiconductor laser
- temperature
- drive circuit
- case
- semiconductor
- 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 34
- 238000012544 monitoring process Methods 0.000 claims abstract description 4
- 150000001875 compounds Chemical class 0.000 claims abstract description 3
- 238000009413 insulation Methods 0.000 claims 1
- 239000003990 capacitor Substances 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000010292 electrical insulation Methods 0.000 description 1
- 230000010355 oscillation 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
- H01S5/06—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
-
- 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
- H01S5/02—Structural details or components not essential to laser action
- H01S5/024—Arrangements for thermal management
- H01S5/02407—Active cooling, e.g. the laser temperature is controlled by a thermo-electric cooler or water cooling
- H01S5/02415—Active cooling, e.g. the laser temperature is controlled by a thermo-electric cooler or water cooling by using a thermo-electric cooler [TEC], e.g. Peltier element
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】
［産業上の利用分野］
この種の回路として、第２図に示すような回路導体レー
ザＬＤとトランジスタＴｒのエミッターコレクタとを正
電源電圧＋Ｖと大地電位Ｇとの間に接続する。増幅器Ａ
ｔの一方の入力端子には正電源電圧＋Ｖと大地電位Ｇと
の間に直列に接続した抵抗Ｒ１，可変抵抗ＶＲおよび抵
抗Ｒ２の可変抵抗ＶＲの可変出力端子から取り出した電
圧Ｃ−を印加し、同他方の入力端子には正電源電圧＋Ｖ
と大地電位Ｇとの間に直列に接続した抵抗Ｒ３とサーミ
スタＲ４との接続点の電圧Ｃ＋を印加する。増幅器Ａ１
の出力を抵抗Ｒ５とＲ８を介してトランジスタＴｒのベ
ースに供給する。フォトダイオードＰＤの出力を増幅器
Ａ１の他方の入力端子に供給する。抵抗Ｒ５とＲ６の接
続点と正電源電圧＋Ｖとの間にコンデンサＣを接続する
。[Detailed Description of the Invention] [Field of Industrial Application] As a circuit of this type, a circuit conductor laser LD and an emitter collector of a transistor Tr as shown in FIG. 2 are connected between a positive power supply voltage +V and a ground potential G. Connect to. Amplifier A
A voltage C- taken out from the variable output terminal of the variable resistor VR of the resistor R1, variable resistor VR, and resistor R2 connected in series between the positive power supply voltage +V and the ground potential G is applied to one input terminal of t. , the other input terminal is connected to the positive power supply voltage +V
A voltage C+ is applied at a connection point between a resistor R3 and a thermistor R4 connected in series between the ground potential G and the ground potential G. Amplifier A1
The output of the transistor Tr is supplied to the base of the transistor Tr via resistors R5 and R8. The output of the photodiode PD is supplied to the other input terminal of the amplifier A1. A capacitor C is connected between the connection point of resistors R5 and R6 and the positive power supply voltage +V.
この回路は以下のように動作する。This circuit operates as follows.
まず、増幅器Ａ１の入力電圧６”、６−は次式でｒｔ
＋ｒ２ ’可変抵抗ＶＲの値、
ｉ：半導体レーザＬＤの出力光量モニタ用フォトダイオ
ードＰＤの出力電流
増幅器Ａ１の出力Ｃ０は増幅器ＡＩのゲインをＡとして
（３）式で示される。First, the input voltages 6'' and 6- of the amplifier A1 are expressed as rt
+r2' Value of variable resistor VR, i: Output C0 of the output current amplifier A1 of the photodiode PD for monitoring the output light amount of the semiconductor laser LD is expressed by equation (3) where A is the gain of the amplifier AI.
６ｏ＝Ａ（ｅ＋ −６−）＋６− （３）すな
わち、（１）、（２）式で示される入力電圧Ｏ＋と〇−
の差（ｅ＋−ｅ−）は増幅器Ａ１で増幅され、（ｅ＋−
ｅ−）＞ｏのときは増幅器Ａ１の出力Ｃ０はＣ−よりも
大きくなり、（ｅ” −ｅ−）く０のときはＣ−よりも
小さくなる。6o=A(e+ -6-)+6- (3) That is, the input voltage O+ and 〇- shown in equations (1) and (2)
The difference (e+-e-) is amplified by amplifier A1, and the difference (e+-e-
When e-)>o, the output C0 of amplifier A1 is larger than C-, and when (e''-e-)>0, it is smaller than C-.
回路全体の発振防止用の抵抗ＲへとコンデンサＣから成
る一次遅れ要素を経て増幅器Ａ１の出力Ｃｏは平滑化さ
れ、抵抗Ｒ６を経由してトランジこれにより半導体レー
ザＬＤの発光量の変動は補償され、増幅器Ａ１の出力Ｃ
０がＣ−になるように制御されることになる。すなわち
、可変抵抗で調整できる電圧Ｏ−を小さく（大きく）す
れば、Ｃ０も小さく（大きく）なりトランジスタＴｒの
ベース電流は大きく（小さく）なる、これにより半導体
レーザＬＤの発光量を調整できることが分る。The output Co of the amplifier A1 is smoothed by passing through a first-order delay element consisting of a capacitor C to a resistor R for preventing oscillation of the entire circuit, and is transferred to a transistor via a resistor R6, thereby compensating for fluctuations in the amount of light emitted by the semiconductor laser LD. , the output C of amplifier A1
It will be controlled so that 0 becomes C-. In other words, if the voltage O-, which can be adjusted by the variable resistor, is decreased (increased), C0 also decreases (increases), and the base current of the transistor Tr increases (decreases).This shows that the amount of light emitted by the semiconductor laser LD can be adjusted. Ru.
以上のような従来の半導体レーザの駆動回路には次のよ
うな問題点がある。The conventional semiconductor laser drive circuit as described above has the following problems.
増幅器Ａ１のオフセット電圧の温度特性のために、（３
）式は正確には次の（４）式のようになる。Due to the temperature characteristics of the offset voltage of amplifier A1, (3
) is exactly as shown in the following equation (4).
Ｏｏ ＝Ａ＠ （ｅ” −６−＋６−＊ Ｋ＠Ｔ）
＋６−Ｔ：増幅器Ａ１の発光光量（”Ｏ）
すなわち、増幅器ＡＩを理想的なものとすれば、になる
、開式はＣ１・に−Ｔの項のために、増幅器Ａ１の発光
光量Ｔの変化に伴い６ｏが変化することを意味している
。Oo = A@ (e” −6−+6−* K@T)
+6-T: Amount of light emitted from amplifier A1 ("O) In other words, if amplifier AI is ideal, the following equation is obtained. Because of the term -T in C1, the amount of light emitted from amplifier A1 T This means that 6o changes with the change.
換言すれば、（４）式は、半導体レーザＬＤの光量変動
がないにもかかわらず増幅器Ａ１の出力ＯＯはオフセッ
ト電圧Ｃ１の温度特性のために変化し、Ｋが正の値の場
合は温度上昇とともにＣＯが増大し、またＫの値が負の
場合は温度上昇とともにＣＯが減少することを意味して
いる。In other words, equation (4) shows that even though there is no variation in the light intensity of the semiconductor laser LD, the output OO of the amplifier A1 changes due to the temperature characteristics of the offset voltage C1, and if K is a positive value, the temperature rises. A negative value of K means that CO decreases as the temperature increases.
このように、もともと半導体ＬＤに光量変動がなかった
にもかかわらず、発光光量の変動によりトランジスタＴ
ｒのベース電流が変化し、半導体レーザＬＤに流す電流
を変化させ、ＬＤの発光光量が変動してしまうという欠
点があった。In this way, even though the semiconductor LD originally had no fluctuation in the amount of light, due to the fluctuation in the amount of emitted light, the transistor T
There is a drawback that the base current of r changes, the current flowing through the semiconductor laser LD changes, and the amount of light emitted from the LD fluctuates.
路の発光光量に影響されないように構成した半導かかる
目的を達成するために、本発明は、半導駆動電流を少な
くシ、小さいときには半導体レーザの動電流を大きくす
るよう動作し、半導体レーザの発光光量が所定の値にな
るように制御する半導体レーザ駆動回路を、当該駆動回
路の温度を検出するためのサーミスタとともに熱伝導性
の良好なケース内に、電気絶縁性は高くかつ熱伝導性の
良好なサーマルコンパウンドで、埋めて一体化し、サー
ミスタにより検出される温度信号を設定温度と比較し、
その比較出力に基づいてケースに密着して配設したペル
チェ素子に流す電流を制御することにより、ケースの発
光光量が変化してもケース内の半導体レーザ駆動回路の
温度が一定になるようになしたことを特徴とする。In order to achieve the above object, the present invention operates to reduce the semiconductor drive current and increase the dynamic current of the semiconductor laser when it is small, thereby increasing the dynamic current of the semiconductor laser. A semiconductor laser drive circuit that controls the amount of emitted light to a predetermined value is housed in a case with good thermal conductivity, along with a thermistor that detects the temperature of the drive circuit. Fill and integrate with a good thermal compound, compare the temperature signal detected by the thermistor with the set temperature,
By controlling the current flowing through the Peltier element placed in close contact with the case based on the comparative output, the temperature of the semiconductor laser drive circuit inside the case can be kept constant even if the amount of light emitted by the case changes. It is characterized by what it did.
［作 用］
本発明では、半導体レーザ駆動回路をペルチェ素子を使
って発光光量の変化に関係なく定温制御することにより
、半導体レーザ駆動回路の温度時ザ定出力駆動回路を得
ることができる。[Function] In the present invention, by controlling the semiconductor laser drive circuit at a constant temperature using a Peltier element regardless of changes in the amount of emitted light, it is possible to obtain a constant output drive circuit depending on the temperature of the semiconductor laser drive circuit.
第１図は、本発明の実施例を示すものである。FIG. 1 shows an embodiment of the invention.
ここで、第２図と同様の個所には同一符号を付す。Here, the same parts as in FIG. 2 are given the same reference numerals.
第１図において、ＣＡは第２図示の半導体駆動回路およ
び同ケース内の温度を検出するためのサーミスタＲ１′
を収納した銅ケースであり、その内部には、熱伝導が良
好で、かつ電気絶縁性の高いフンパウンドＣ０Ｎ（水谷
電機工業株式会社のＣＡＳＴＡＬＬ８００など）を充填
して上記回路を埋めである。In FIG. 1, CA represents the semiconductor drive circuit shown in FIG. 2 and a thermistor R1' for detecting the temperature inside the case.
The inside of the case is filled with Funpound C0N (such as CASTALL 800 manufactured by Mizutani Electric Industry Co., Ltd.), which has good thermal conductivity and high electrical insulation properties, and the circuit is filled with the above-mentioned circuit.
抵抗Ｒ１１〜Ｒ，うおよびサーミスタＲ１，から構成さ
れたブリッジ回路により、温度設定値（抵抗Ｒ１１とＲ
１１の接続点の電位）と測定温度（抵抗Ｒ１１とサーミ
スタＲとの接続点の電位）との差が抵抗Ｒ４〜Ｒ１１お
よび増幅器Ａ２とから成る差動増幅器により増幅される
。The temperature setting value (resistors R11 and R
The difference between the potential at the connection point of resistor R11 and the measured temperature (the potential at the connection point of resistor R11 and thermistor R) is amplified by a differential amplifier including resistors R4 to R11 and amplifier A2.
この出力は、パワトランジスタｔｒ１およびｔｒ２スＣ
Ａ内の温度が高ければ、これを下げる方向に、””讐な
わち、設定温度よりケースＣＡ内の温度が低ければ、抵
抗Ｒ１１とＲ，□との接続点の電位は、サーミスタＲ１
４が温度に対して負性抵抗であることを考慮して、抵抗
ＲＩＢとサーミスタＲ１’＋との接続点の電位よりも低
くなるようにブリッジ回路を設計しておく。This output is connected to the power transistors tr1 and tr2
If the temperature inside case CA is high, it will be lowered.In other words, if the temperature inside case CA is lower than the set temperature, the potential at the connection point between resistor R11 and R,
Considering that 4 is a negative resistance with respect to temperature, the bridge circuit is designed so that the potential is lower than the potential of the connection point between the resistor RIB and thermistor R1'+.
これにより、この場合、増幅器Ａ２の出力は大地電位Ｇ
よりも正の電位となり、パワートランジスタｔｒ１がペ
ルチェ素子Ｐに電流を流し込む、ペルチェ素子は電流の
向きによって加熱、冷却ができるので、この場合には、
ペルチェ素子ＰはケースＯＡ内の温度が設定温度よりも
低かったものが設定温度になるよう加熱するように配線
しておくものとする。Therefore, in this case, the output of amplifier A2 is at ground potential G
The potential becomes more positive than that, and the power transistor tr1 flows current into the Peltier element P. Since the Peltier element can be heated or cooled depending on the direction of the current, in this case,
The Peltier element P is wired so that the temperature inside the case OA, which is lower than the set temperature, is heated so that the temperature reaches the set temperature.
逆に設定温度よりケースＣＡ内の温度が高ければ、抵抗
Ｒ４，とＲ１２との接続点の電位が、抵抗Ｒとサーミス
タＲ１１）との接続点の電位よりも高の比により、ケー
スＣＡ内の設定温度を調整できる。Conversely, if the temperature inside case CA is higher than the set temperature, the potential at the connection point between resistors R4 and R12 is higher than the potential at the connection point between resistor R and thermistor R11). You can adjust the set temperature.
第１図において、ペルチェ素子ＰにはフィンＦを取りつ
けておく、このフィンＦは、ペルチェ素子ＰがケースＣ
Ａを冷却する場合にそれに相当する熱を周囲に放散し、
またケースＯＡをペルチェ素子Ｐが加熱する場合にそれ
に相当する熱を周囲から奪う際の効率をよくするための
ものである。In FIG. 1, a fin F is attached to the Peltier element P.
When cooling A, the corresponding heat is dissipated to the surroundings,
Further, when the case OA is heated by the Peltier element P, the heat is removed from the surroundings more efficiently.
なお、第１図においては、第２図と比較し、半導体レー
ザ駆動回路の可変抵抗ＶＲは簡素化のために省略しであ
る。これは、レーザ駆動回路の設計段階において、目標
とする半導体レーザの出力パワーが得られるように、抵
抗Ｒ１，Ｒ２の値を最初から決定しである場合の一例で
あるが、このようにする代わりに、可変抵抗ＶＲを設け
てもよいことは勿論である。Note that in FIG. 1, as compared with FIG. 2, the variable resistor VR of the semiconductor laser drive circuit is omitted for the sake of simplicity. This is an example of a case where the values of resistors R1 and R2 are determined from the beginning in order to obtain the target output power of the semiconductor laser at the design stage of the laser drive circuit, but instead Of course, a variable resistor VR may also be provided.
路を得ることができる。You can get the road.
［発明の効果］
体レーザ駆動回路を温度検出用のサーミスタとともに埋
めて一体化し、そのサーミスタにより検出される温度信
号を設定温度と比較し、この差を電力増幅して上記銅ケ
ースに密着して設置されているペルチェ素子に流す電流
を、発光光量が変化しても銅ケース内の温度が一定にな
るように制御するようにしたので、発光光量が変化して
も差動増幅器のオフセット電圧は一定となり、このため
、従来のように発光光量が変わると半導体レーザの発光
光量が変化する欠点をなくすことができ、発光光量の変
化に対し、非常に安定した半導体レーザ定出力駆動回路
を得ることができる。[Effects of the invention] The body laser drive circuit is embedded and integrated with a thermistor for temperature detection, the temperature signal detected by the thermistor is compared with the set temperature, and this difference is amplified in power. The current flowing through the installed Peltier element is controlled so that the temperature inside the copper case remains constant even if the amount of emitted light changes, so the offset voltage of the differential amplifier remains unchanged even if the amount of emitted light changes. Therefore, it is possible to eliminate the conventional drawback that the amount of emitted light of the semiconductor laser changes when the amount of emitted light changes, and to obtain a semiconductor laser constant output drive circuit that is extremely stable against changes in the amount of emitted light. I can do it.
第１図は本発明の一実施例を示す回路図、第２図は従来
の半導体レーザ定出力駆動回路の一例を示す回路図であ
る。
Ｒ１〜 Ｒ３、Ｒ５・Ｒ６・Ｒ１１〜 Ｒ＋５・ＲＩＢ
〜Ｒ＋９・・・固定抵抗、
Ｒ４、Ｒ１７・・・サーミスタ、
Ａｔ、Ａ２・・・増幅器、
Ｔｒ、 ｔｒｌ 、 ｔｒ２・・・パワートランジス
タＣ１・・・コンデンサ、
ＣＰＭ・・・サーマルコンバウンド、
ＯＡ・・・銅ケース、
ＰＤ・・・半導体レーザ光量モニタ用
フォトダイオード、
ＬＤ・・・半導体レーザ、
Ｐ・・・ペルチェ素子、
Ｆ・・・フィン。FIG. 1 is a circuit diagram showing an embodiment of the present invention, and FIG. 2 is a circuit diagram showing an example of a conventional semiconductor laser constant output drive circuit. R1~R3, R5・R6・R11~R+5・RIB
~R+9...Fixed resistance, R4, R17...Thermistor, At, A2...Amplifier, Tr, trl, tr2...Power transistor C1...Capacitor, CPM...Thermal combine, OA・...Copper case, PD...Photodiode for semiconductor laser light intensity monitoring, LD...Semiconductor laser, P...Peltier element, F...Fin.
Claims (1)
ダイオードを設け、該フォトダイオードの電流が設定値
と比較して大きいときには前記半導体レーザの駆動電流
を少なくし、小さいときには前記半導体レーザの動電流
を大きくするよう動かし、前記半導体レーザの発光光量
が所定の値になるように制御する半導体レーザ駆動回路
を、当該駆動回路の温度を検出するためのサーミスタと
ともに熱伝導性の良好なケース内に、電気絶縁性は高く
かつ熱伝導性の良好なサーマルパウンドで、埋めて一体
化し、前記サーミスタにより検出される温度信号を設定
温度と比較し、その比較出力に基づいて前記ケースに密
着して配設したペルチェ素子に流す電流を制御すること
により、前記ケースの周囲温度が変化しても前記ケース
内の前記半導体レーザ駆動回路の温度が一定になるよう
になしたことを特徴とする半導体レーザ定出力駆動回路
。A photodiode for monitoring the amount of emitted light is provided close to the semiconductor laser, and when the current of the photodiode is large compared to a set value, the driving current of the semiconductor laser is reduced, and when it is small, the dynamic current of the semiconductor laser is reduced. A semiconductor laser drive circuit that controls the amount of light emitted by the semiconductor laser to a predetermined value is housed in a case with good thermal conductivity, along with a thermistor for detecting the temperature of the drive circuit. A thermal compound with high insulation properties and good thermal conductivity is embedded and integrated, and the temperature signal detected by the thermistor is compared with the set temperature, and based on the comparison output, it is placed in close contact with the case. A semiconductor laser constant output drive characterized in that the temperature of the semiconductor laser drive circuit inside the case is kept constant even if the ambient temperature of the case changes by controlling the current flowing through the Peltier element. circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6059586A JPS62219680A (en) | 1986-03-20 | 1986-03-20 | Constant-output drive circuit for semiconductor laser |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6059586A JPS62219680A (en) | 1986-03-20 | 1986-03-20 | Constant-output drive circuit for semiconductor laser |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS62219680A true JPS62219680A (en) | 1987-09-26 |
Family
ID=13146745
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6059586A Pending JPS62219680A (en) | 1986-03-20 | 1986-03-20 | Constant-output drive circuit for semiconductor laser |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS62219680A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63265480A (en) * | 1987-04-23 | 1988-11-01 | Nec Corp | Optical transmission equipment |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5914362B2 (en) * | 1980-02-26 | 1984-04-04 | 横浜ゴム株式会社 | tire filling |
-
1986
- 1986-03-20 JP JP6059586A patent/JPS62219680A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5914362B2 (en) * | 1980-02-26 | 1984-04-04 | 横浜ゴム株式会社 | tire filling |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63265480A (en) * | 1987-04-23 | 1988-11-01 | Nec Corp | Optical transmission equipment |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5966938A (en) | Peltier control circuit and a peltier device structure | |
| US6725669B2 (en) | Thermoelectric cooler temperature control | |
| GB2131607A (en) | Semiconductor laser device | |
| JPS62244184A (en) | Oscillating frequency and output stabilizer for semiconductor laser | |
| JP3320900B2 (en) | Automatic temperature control circuit for laser diode and electric / optical signal conversion unit using the same | |
| JP5308294B2 (en) | Peltier element cooling control circuit | |
| JP2005244242A (en) | Apparatus provided with at least one beam radiation semiconductor device, and method of stabilizing operating temperature of the beam radiation semiconductor device | |
| WO2014192211A1 (en) | Cooling control circuit and electrostatic atomizing device comprising same | |
| US6236668B1 (en) | Semiconductor laser apparatus and pumping circuit therefor | |
| US4810934A (en) | Electron emission device | |
| US20030227694A1 (en) | Laser diode module, laser diode device and optical transmitter incorporating the same | |
| JPS62219680A (en) | Constant-output drive circuit for semiconductor laser | |
| CN114023739B (en) | Temperature sensing circuit and thermal feedback protection circuit | |
| JP2007180378A (en) | Laser module and control method therefor | |
| JP2690221B2 (en) | Semiconductor integrated circuit | |
| US5185559A (en) | Supply circuit for P-N junction cathode | |
| JPH0532917B2 (en) | ||
| JPH1126849A (en) | Current supply source and semiconductor laser drive circuit | |
| JPH11218405A (en) | Rotation position detector | |
| KR940007495Y1 (en) | Thermal control circuit of laser diode | |
| JP2005092793A (en) | Electronic appliance circuit | |
| JPH11118562A (en) | Thermal flowmeter | |
| JPH04321114A (en) | Object temperature control system | |
| JP2001044371A (en) | Semiconductor integrated circuit | |
| JPH0564366B2 (en) |