CN215221265U - Automatic current control system for single-wavelength semiconductor laser - Google Patents

Automatic current control system for single-wavelength semiconductor laser Download PDF

Info

Publication number
CN215221265U
CN215221265U CN202121216214.4U CN202121216214U CN215221265U CN 215221265 U CN215221265 U CN 215221265U CN 202121216214 U CN202121216214 U CN 202121216214U CN 215221265 U CN215221265 U CN 215221265U
Authority
CN
China
Prior art keywords
laser
resistor
photodetector
semiconductor laser
pin
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.)
Active
Application number
CN202121216214.4U
Other languages
Chinese (zh)
Inventor
赵番
司俊
朱旭晨
李晓军
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.)
Shanghai Special Equipment Supervision and Inspection Technology Institute
Original Assignee
Shanghai Special Equipment Supervision and Inspection Technology Institute
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 Shanghai Special Equipment Supervision and Inspection Technology Institute filed Critical Shanghai Special Equipment Supervision and Inspection Technology Institute
Priority to CN202121216214.4U priority Critical patent/CN215221265U/en
Application granted granted Critical
Publication of CN215221265U publication Critical patent/CN215221265U/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Landscapes

  • Semiconductor Lasers (AREA)

Abstract

The utility model provides a single wavelength semiconductor laser automatic current control system, single wavelength semiconductor laser has laser LD and photodetector PD dorsad, the negative pole pin of laser LD and the positive pole pin ground connection of photodetector PD dorsad, the positive pole pin LD + of laser LD and the negative pole pin PD-of photodetector PD dorsad connect the positive voltage, a serial communication port, automatic current control system includes mirror current source circuit, reference voltage supply circuit, N passageway MOSFET Q7 and resistance R2. The utility model discloses a current feedback control return circuit carries out closed-loop control to semiconductor laser's injection current to reach the stable purpose of output optical power. Compared with the prior art, the utility model discloses following beneficial effect has: the circuit has the advantages of simple structure, high reliability and low power consumption, and solves the problems of complex circuit, high cost and poor stability in the conventional system.

Description

Automatic current control system for single-wavelength semiconductor laser
Technical Field
The utility model relates to a semiconductor laser automatic current control system forms the negative feedback with the electric current of detector dorsad and controls laser instrument drive current to reach constant current control's purpose, belong to the automated control field.
Background
Semiconductor lasers are widely used in various fields as an important light source. In practical application, the semiconductor laser is affected by the external power supply voltage and temperature variation, resulting in fluctuation of the output power of the laser. At this time, if the driving current of the laser is changed, the driving threshold current of the laser may be exceeded, so that the performance of the laser may be drastically reduced to damage and fail. Therefore, the stability and modulation accuracy of the semiconductor laser driving circuit are required to be high.
The conventional semiconductor laser is designed with a voltage limiting and current limiting module to ensure that the laser LD works within the range of limit voltage and current. The design generally uses a singlechip to control a high-precision digital-to-analog converter, and a discrete device is additionally arranged to ensure the stability of output power, and the circuit has the advantages of complex structure, high cost and poor stability.
Disclosure of Invention
The utility model aims at: the safe and reliable operation of the semiconductor laser is ensured.
In order to achieve the above object, the present invention provides an automatic current control system for a single-wavelength semiconductor laser, the single-wavelength semiconductor laser has a laser LD and a back light detector PD, a cathode pin of the laser LD and an anode pin of the back light detector PD are grounded, an anode pin LD + of the laser LD and a cathode pin PD-of the back light detector PD are connected to a positive voltage, and the automatic current control system includes a mirror current source circuit, a reference voltage supply circuit, an N-channel MOSFET Q7 and a resistor R2, wherein:
the input end of the mirror current source circuit is connected with the constant voltage source DVDD and is provided with two output ends, and currents output by the two output ends of the mirror current source circuit are in a mirror image relation; one output end of the mirror current source circuit is connected with an anode pin LD + of the laser LD, and the other output end of the mirror current source circuit is connected with the drain electrode of an N-channel MOSFET Q7;
the reference voltage provided by the reference voltage supply circuit and the voltage difference formed after the photocurrent coupled to the cathode pin PD — facing away from the photodetector PD flows through the resistor R2 are applied to the gate of the N-channel MOSFET Q7, and the source of the N-channel MOSFET Q7 is grounded.
Preferably, the mirror current source circuit comprises a PNP transistor Q5, a PNP transistor Q6, a resistor R3 and a resistor R4; the emitter of the PNP triode Q5 and the emitter of the PNP triode Q6 are connected with a constant voltage source DVDD; the base electrode of the PNP triode Q5 is connected with the base electrode of the PNP triode Q6; an anode pin LD + of the laser LD is connected with a collector of a PNP triode Q5 through a resistor R3; the base electrode of the PNP triode Q6 is connected with the collector electrode, and the drain electrode of the N-channel MOSFET Q7 is connected with the collector electrode of the PNP triode Q6 through a resistor R4; the current I1 of the collector of the PNP triode Q5 and the PNP triode Q6 is in mirror image relation with the current I2.
Preferably, the reference voltage supply circuit comprises a resistor R6 and a voltage reference chip U4, one end of the resistor R6 is connected to a constant voltage source DVDD, the other end is connected to the cathode of the voltage reference chip U4 and one end of the resistor R2, and the anode of the voltage reference chip U4 is grounded; the other end of the resistor R2 is connected with the gate of the N-channel MOSFET Q7, and the gate of the N-channel MOSFET Q7 is also connected with the cathode pin PD-which faces away from the light detector PD.
The utility model discloses a current feedback control return circuit carries out closed-loop control to semiconductor laser's injection current to reach the stable purpose of output optical power. Compared with the prior art, the utility model discloses following beneficial effect has: the circuit has the advantages of simple structure, high reliability and low power consumption, and solves the problems of complex circuit, high cost and poor stability in the conventional system.
Drawings
FIG. 1 is a schematic diagram of an internal structure of a semiconductor laser for use in an automatic current control system for the semiconductor laser;
fig. 2 is a circuit diagram of an automatic current control system for a semiconductor laser.
Detailed Description
The present invention will be further described with reference to the following specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Furthermore, it should be understood that various changes and modifications of the present invention may be made by those skilled in the art after reading the teachings of the present invention, and these equivalents also fall within the scope of the appended claims.
As shown in fig. 1, the utility model discloses the laser of chooseing for use has laser LD and back photodetector PD, and laser LD is used for sending laser, and back photodetector PD is used for detecting the laser intensity that laser LD sent. The back light detector PD converts a portion of the received optical power into a monitoring current, which is proportional to the laser power received by the back light detector PD, thereby controlling the output optical power of the laser LD.
In this embodiment, when the cathode pin of the laser LD is grounded, the anode pin of the laser LD is connected to a positive voltage. When the anode pin of the back light detector PD is grounded, the cathode pin of the back light detector PD is connected with a positive voltage to form reverse bias, so that the aim of forward driving the laser diode is fulfilled.
In a normal state, the laser LD operates at a set driving current, and the driving current I is proportional to the output optical power of the laser. When the output power of the laser LD increases, the photocurrent coupled to the feedback terminal facing away from the photodetector PD also increases proportionally. When the output optical power of the laser LD decreases, the photocurrent coupled to the feedback terminal of the back photodetector PD decreases accordingly.
The utility model discloses a circuit converts the photocurrent that will be dorsad light detector PD feedback end into voltage through series resistance, controls laser LD's drive current through voltage change to reach current automatic control's purpose. When the output photocurrent of the laser LD is reduced, the injection current of the laser LD is increased by the N-channel MOSFET to maintain the stability of the output power. On the contrary, if the output photocurrent of the laser LD increases, the injection current of the laser LD decreases.
As shown in fig. 2, the present invention provides an automatic current control system for a semiconductor laser, comprising: PNP triodes Q5, Q6, resistors R3, R4, R2, R6, a voltage reference chip U4 and an N-channel MOSFET Q7.
The cathode pin PD-of the back photodetector PD is connected to the gate (pin 1) of the N-channel MOSFET Q7 and is electrically connected to the cathode of the voltage reference chip U4 through a resistor R2. The opening of the gate of the N-channel MOSFET Q7 is affected by the cathode pin PD-voltage and the reference voltage output by the voltage reference chip U4.
The PNP triodes Q5 and Q6 and the resistors R3 and R4 form a mirror current source circuit. The anode pin LD + of the laser LD is connected with the collector (pin 3) of the PNP triode Q5 through a resistor R3, and the drain (pin 3) of the N-channel MOSFET Q7 is connected with the collector (pin 3) of the PNP triode Q6 through a resistor R4. The PNP triode is designed so that currents I1 and I2 of collectors of the PNP triodes Q5 and Q6 are in a mirror image relation.
When the applied power supply voltage suddenly increases, the forward voltage of the semiconductor laser at its PN junction increases, the injection current of the laser LD increases, and the output laser power of the laser LD suddenly increases. When the ambient temperature decreases, the output power of the laser LD also abruptly increases. The sudden increase in the output power of the laser LD causes a proportional increase in the photocurrent coupled to the cathode pin PD-facing away from the photodetector PD. The photocurrent coupled to the cathode pin PD — facing away from the photodetector PD passes through the resistor R2, and the voltage difference formed across the resistor R2 increases. Since the reference voltage outputted by the voltage reference chip U4 is not changed, the gate (pin 1) voltage of the N-channel MOSFET Q7 is decreased, the opening between the drain (pin 3) and the source (pin 2) of the N-channel MOSFET Q7 is decreased, and the drain current is decreased. The other end of the mirror current source circuit is connected with an anode pin LD + of the laser LD, the current on the anode pin LD + of the laser LD is reduced, the driving current of the laser LD is reduced, the power of the laser LD is reduced, the light emission is weakened, and the previous light emission intensity is recovered.
When the external power supply voltage suddenly decreases, the forward voltage of the semiconductor laser at the PN junction thereof decreases, the injection current of the laser LD decreases, and the output laser power of the laser LD suddenly decreases. When the ambient temperature rises, the output power of the laser LD also abruptly decreases. The sudden decrease of the output power of the laser LD causes the photocurrent coupled to the cathode pin PD-facing away from the photo detector PD to also decrease proportionally. The photocurrent coupled to the cathode pin PD — facing away from the photodetector PD passes through the resistor R2, and the voltage difference formed across the resistor R2 decreases. Since the reference voltage outputted from the voltage reference chip U4 is not changed, the voltage of the gate (pin 1) of the N-channel MOSFET Q7 increases, the opening between the drain (pin 3) and the source (pin 2) of the N-channel MOSFET Q7 increases, and the drain current increases. The other end of the mirror current source circuit is connected with an anode pin LD + of the laser LD, so that the current on the anode pin LD + of the laser LD is increased, the driving current of the laser LD is increased, the laser power is increased, the light emission is enhanced, and the previous light emission intensity is recovered. The driving current of the laser LD is controlled by the current back to the photodetector PD, thereby achieving the purpose of automatic current control of the semiconductor laser.

Claims (3)

1.一种单波长半导体激光器自动电流控制系统,所述单波长半导体激光器具有激光器LD和背向光探测器PD,激光器LD的阴极管脚以及背向光探测器PD的阳极管脚接地,激光器LD的阳极管脚LD+及背向光探测器PD的阴极管脚PD-接正电压,其特征在于,所述自动电流控制系统包括镜像电流源电路、基准电压供给电路、N通道MOSFET Q7以及电阻R2,其中:1. A single-wavelength semiconductor laser automatic current control system, the single-wavelength semiconductor laser has a laser LD and a back-facing photodetector PD, and the cathode pin of the laser LD and the anode pin of the back-facing photodetector PD are grounded, and the laser The anode pin LD+ of the LD and the cathode pin PD- facing away from the photodetector PD are connected to a positive voltage. It is characterized in that the automatic current control system includes a mirror current source circuit, a reference voltage supply circuit, an N-channel MOSFET Q7 and a resistor. R2, where: 镜像电流源电路的输入端连接恒压源DVDD,并具有两个输出端,镜像电流源电路的两个输出端输出的电流呈镜像关系;镜像电流源电路的一个输出端与激光器LD的阳极管脚LD+相连,另一个输出端连接N通道MOSFET Q7的漏极;The input end of the mirror current source circuit is connected to the constant voltage source DVDD, and has two output ends. The current output by the two output ends of the mirror current source circuit is in a mirror image relationship; one output end of the mirror current source circuit is connected to the anode tube of the laser LD. The pin LD+ is connected, and the other output end is connected to the drain of the N-channel MOSFET Q7; 基准电压供给电路提供的基准电压与耦合至背向光探测器PD的阴极管脚PD-的光电流流经电阻R2后形成的电压差共同加载至N通道MOSFET Q7的栅极,N通道MOSFET Q7的源极接地。The reference voltage provided by the reference voltage supply circuit and the voltage difference formed by the photocurrent coupled to the cathode pin PD- facing away from the photodetector PD flowing through the resistor R2 are jointly loaded to the gate of the N-channel MOSFET Q7, and the N-channel MOSFET Q7 The source is grounded. 2.如权利要求1所述的一种单波长半导体激光器自动电流控制系统,其特征在于,所述镜像电流源电路包括PNP三极管Q5、PNP三极管Q6、电阻R3和电阻R4;PNP三极管Q5的射极及PNP三极管Q6的射极连接恒压源DVDD;PNP三极管Q5的基极与PNP三极管Q6的基极相连;所述激光器LD的阳极管脚LD+通过电阻R3接PNP三极管Q5的集电极;PNP三极管Q6的基极与集电极相连,N通道MOSFET Q7的漏极通过电阻R4接PNP三极管Q6的集电极;PNP三极管Q5、PNP三极管Q6集电极的电流I1与电流I2呈镜像关系。2. a kind of single-wavelength semiconductor laser automatic current control system as claimed in claim 1 is characterized in that, described mirror current source circuit comprises PNP triode Q5, PNP triode Q6, resistance R3 and resistance R4; The radiation of PNP triode Q5. The pole and the emitter of the PNP transistor Q6 are connected to the constant voltage source DVDD; the base of the PNP transistor Q5 is connected to the base of the PNP transistor Q6; the anode pin LD+ of the laser LD is connected to the collector of the PNP transistor Q5 through the resistor R3; PNP The base of the transistor Q6 is connected to the collector, and the drain of the N-channel MOSFET Q7 is connected to the collector of the PNP transistor Q6 through the resistor R4; the current I1 of the PNP transistor Q5 and the collector of the PNP transistor Q6 is in a mirror image relationship with the current I2. 3.如权利要求1所述的一种单波长半导体激光器自动电流控制系统,其特征在于,所述基准电压供给电路包括电阻R6、电压参考芯片U4,电阻R6的一端连接恒压源DVDD,另一端接电压参考芯片U4的阴极以及所述电阻R2的一端,电压参考芯片U4的阳极接地;所述电阻R2的另一端接所述N通道MOSFET Q7的栅极,所述N通道MOSFET Q7的栅极还连接所述背向光探测器PD的阴极管脚PD-。3. a kind of single-wavelength semiconductor laser automatic current control system as claimed in claim 1 is characterized in that, described reference voltage supply circuit comprises resistor R6, voltage reference chip U4, one end of resistor R6 is connected with constant voltage source DVDD, and another One end is connected to the cathode of the voltage reference chip U4 and one end of the resistor R2, and the anode of the voltage reference chip U4 is grounded; the other end of the resistor R2 is connected to the gate of the N-channel MOSFET Q7, and the gate of the N-channel MOSFET Q7 The pole is also connected to the cathode pin PD- facing away from the photodetector PD.
CN202121216214.4U 2021-06-01 2021-06-01 Automatic current control system for single-wavelength semiconductor laser Active CN215221265U (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202121216214.4U CN215221265U (en) 2021-06-01 2021-06-01 Automatic current control system for single-wavelength semiconductor laser

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202121216214.4U CN215221265U (en) 2021-06-01 2021-06-01 Automatic current control system for single-wavelength semiconductor laser

Publications (1)

Publication Number Publication Date
CN215221265U true CN215221265U (en) 2021-12-17

Family

ID=79422770

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202121216214.4U Active CN215221265U (en) 2021-06-01 2021-06-01 Automatic current control system for single-wavelength semiconductor laser

Country Status (1)

Country Link
CN (1) CN215221265U (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113193476A (en) * 2021-06-01 2021-07-30 上海市特种设备监督检验技术研究院 Automatic current control system of single-wavelength semiconductor laser

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113193476A (en) * 2021-06-01 2021-07-30 上海市特种设备监督检验技术研究院 Automatic current control system of single-wavelength semiconductor laser
CN113193476B (en) * 2021-06-01 2025-01-28 上海市特种设备监督检验技术研究院 An automatic current control system for single-wavelength semiconductor lasers

Similar Documents

Publication Publication Date Title
CN215221265U (en) Automatic current control system for single-wavelength semiconductor laser
US20070030868A1 (en) Driving circuit and driving method for laser light source
CN201796077U (en) Laser device bias current monitoring circuit with APC (automatic phase control) function
CN205657891U (en) Temperature detection module and have drive power supply system of temperature control function
CN110086084A (en) It is a kind of with automatic temperature-controlled constant-current source type semiconductor laser device driving circuit
CN113193476B (en) An automatic current control system for single-wavelength semiconductor lasers
CN212908511U (en) Double closed-loop negative feedback control system based on laser
CN202930744U (en) A coaxial pigtail laser drive circuit
CN217443794U (en) Over-temperature frequency reduction protection circuit
CN115799980B (en) Laser control system
JP2801825B2 (en) Photo coupler device
CN108469868B (en) Temperature self-adaptive current source and optical module
CN106451060B (en) Laser driving circuit
CN210926605U (en) Laser control circuit
JPH06326384A (en) Semiconductor laser element drive circuit
CN114122906B (en) A semiconductor optical amplifier drive protection circuit, its control method, and optical module
CN109375687B (en) Anti-irradiation bipolar temperature monitoring circuit
CN208999860U (en) A semiconductor laser optical power stabilization control loop
CN114597858B (en) Chip over-temperature protection circuit and corresponding chip and chip circuit
CN206076727U (en) A kind of frequency power exports stable drive circuit for laser
CN221828353U (en) LD pumping source protection system of medical laser
CN111854947A (en) Light energy detector circuit capable of detecting picowatt-level micro light signals
CN220136518U (en) Battery pack temperature detection circuit
CN201796078U (en) Laser bias current monitoring circuit with APC
CN206076725U (en) A kind of drive circuit for laser

Legal Events

Date Code Title Description
GR01 Patent grant
GR01 Patent grant