Laser operating temperature control circuit and control method thereof

Abstract

The present invention discloses a laser operating temperature control circuit and a control method thereof, comprising a main control chip U1A, a monitoring circuit, a configuration circuit, a temperature feedback circuit, and a laser. The laser includes a built-in thermistor, the main control chip U1A is connected to the configuration circuit and the temperature feedback circuit respectively, the monitoring circuit is connected to the configuration circuit, the configuration circuit is connected to the temperature feedback circuit, and the temperature feedback circuit is connected to the thermistor built into the laser. The present invention has the advantage of resolving the contradiction between the speed and stability of laser temperature regulation and quickly and stably regulating the temperature of the laser.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit design optimization, and more particularly to a laser operating temperature control circuit and a control method thereof. Background Art

[0002] In recent years, the application of tunable diode laser absorption spectroscopy (TDLAS) for remote methane concentration monitoring has gained widespread adoption. In methane remote sensing systems, precise control of the wavelength of the tunable diode laser (DFB) plays a key role in accurately measuring gas concentration. The DFB's output center wavelength must be aligned with the methane absorption peak. Changes in the DFB's injection current and temperature can cause variations in its output wavelength, so maintaining a stable DFB operating temperature is crucial in practical applications.

[0003] Chinese Patent Publication No. CN108508940A discloses a laser temperature feedback control circuit and method. This circuit regulates the current output to the laser TEC terminal based on the feedback laser temperature. The circuit uses an STM32 chip to control an ADN8830 temperature control chip. The STM32 chip controls the current output to the laser TEC terminal by adjusting the voltage output to the ADN8830 temperature control chip. A knob controls the input terminal to set the high and low current values ​​of the laser TEC current, as well as the threshold for determining when the temperature has reached the set value. The ADN8830 temperature control chip provides feedback on the laser's temperature signal. When the laser temperature does not reach the set value, the current output is controlled at the set high current, increasing the temperature regulation speed. When the laser temperature reaches the set value, the current output is controlled at the set low current, increasing the regulation stability. Like existing laser temperature control circuits, this circuit sets a certain current output, and when the laser temperature reaches the set value, the current output remains at that current. If the adjustment speed needs to be fast, the current will be set larger. When the set temperature is reached, the amplitude of the temperature adjustment oscillation will be larger due to the large control current, and the stability will be worse than when the current is smaller. If small current control is used, although the stability is higher after reaching the set temperature, the temperature adjustment speed is slower before the set temperature is reached, and the speed of temperature adjustment and the stability of adjustment become contradictory. Summary of the Invention

[0004] The technical problem to be solved by the present invention is how to provide a laser operating temperature control circuit and a control method thereof that resolve the contradiction between the speed and stability of laser temperature regulation.

[0005] The present invention solves the above-mentioned technical problems through the following technical means: a laser operating temperature control circuit, comprising a main control chip U1A, a monitoring circuit, a configuration circuit, a temperature feedback circuit, and a laser. The laser includes a built-in thermistor, and the main control chip U1A is connected to the configuration circuit and the temperature feedback circuit, respectively. The monitoring circuit is connected to the configuration circuit, the configuration circuit is connected to the temperature feedback circuit, and the temperature feedback circuit is connected to the thermistor built into the laser. The thermistor encapsulated in the laser has different resistance values ​​at different ambient temperatures. The thermistor is connected to the temperature feedback circuit, and the main control chip U1A quickly adjusts the temperature by setting the resistance value of the adjustable resistor in the temperature feedback circuit. At the same time, the main control chip U1A adjusts the maximum output current and potential difference of the current output terminal of the configuration circuit. The main control chip U1A determines whether the state is normal based on the direction and magnitude of the output current fed back by the monitoring circuit. If abnormal, the output function of the configuration circuit is disabled, thereby ensuring rapid temperature adjustment while maintaining a large output current, thus resolving the contradiction between temperature adjustment speed and adjustment stability.

[0006] Preferably, a cooling plate is integrated inside the laser, and the cooling plate is connected to the configuration circuit.

[0007] Preferably, the monitoring circuit includes a resistor R3, a resistor R4, a resistor R2, a capacitor C1, an operational amplifier A1, an operational amplifier A2, a diode D1, a diode D2, a transistor Q1, a transistor Q2, a resistor R1 and a comparator U1, one end of the resistor R3 is connected to one end of the resistor R4, the other end of the resistor R4 is connected to one end of the capacitor C1, and the other end of the capacitor C1 is grounded; one end of the capacitor C1 is connected to one end of the resistor R2, and the other end of the resistor R2 is connected to the non-inverting end of the operational amplifier A2; the other end of the resistor R3 is connected to the non-inverting end of the operational amplifier A1, the inverting end of the operational amplifier A1 is connected to the collector of the transistor Q2, the inverting end of the operational amplifier A2 is connected to the collector of the transistor Q1, the positive power supply terminal of the operational amplifier A1 and the operational amplifier The positive power supply terminal of the operational amplifier A2 is connected to the power supply V+, and the negative power supply terminal of the operational amplifier A1 and the negative power supply terminal of the operational amplifier A2 are both connected to the power supply V-; the output terminal of the operational amplifier A1 is connected to the positive electrode of the diode D1, and the negative electrode of the diode D1 is connected to the base of the transistor Q1; the output terminal of the operational amplifier A2 is connected to the positive electrode of the diode D2, and the negative electrode of the diode D2 is connected to the base of the transistor Q2; the emitter of the transistor Q1 is connected to the emitter of the transistor Q2, one end of the resistor R1 is connected to the emitter of the transistor Q1, and the other end is connected to the ADC acquisition module; the inverting terminal of the comparator U1 is connected to the output terminal of the operational amplifier A1, the non-inverting terminal of the comparator U1 is connected to the output terminal of the operational amplifier A2, the positive power supply terminal of the comparator U1 is connected to the power supply V+, and the negative power supply terminal of the comparator U1 is connected to the power supply V-.

[0008] Pin ITEC of TEC controller U4 is connected in series with sampling resistor R4 and capacitor C1, then to ground. The two ends of sampling resistor R4 are connected to a differential amplifier circuit consisting of two op amps, A1 and A2. The outputs of the differential amplifier are connected to the inputs of comparator U1. The voltage level at the output of comparator U1 indicates the direction of the output current of TEC controller U4 (i.e., whether the current flows from the LXP terminal to the LXN terminal or vice versa). After the current flows through sampling resistor R1, the ADC acquisition module collects the voltage amplitude, tracking the output current of TEC controller U4 in real time.

[0009] Preferably, the comparator U1 is of model OP27.

[0010] Preferably, the configuration circuit includes a first adjustable resistor U2, a resistor R5, a TEC controller U4 and a capacitor C6, the fourth pin of the first adjustable resistor U2 is grounded, the eighth pin of the first adjustable resistor U2 is connected to the power supply V1, the sixth pin of the first adjustable resistor U2 is connected to the pin MAXIN of the TEC controller U4, the fifth pin of the first adjustable resistor U2 is connected to the pin MAXV of the TEC controller U4, one end of the resistor R5 is connected to the fifth pin of the first adjustable resistor U2, and the other end of the resistor R5 is grounded; the pin MAXIN and the pin MAXIP as well as the pin VREF of the TEC controller U4 are all connected to the reference power supply VREF; the pin VDD of the TEC controller U4 is connected to the power supply V1, the pin GND of the TEC controller U4 is grounded, and the pin ITEC of the TEC controller U4 is connected to one end of the resistor R3; the pin LXP of the TEC controller U4 is connected to the positive pole of the cooling plate and the pin LXN of the TEC controller U4 is connected to the negative pole of the cooling plate, the cooling plate is a cooling plate integrated inside the laser, the pin COMP of the TEC controller U4 is connected to one end of the capacitor C6, and the other end of the capacitor C6 is grounded. The main control chip U1A adjusts the maximum output current and potential difference of the current output end of the TEC controller U4 by setting the resistance value of the first adjustable resistor U2; the main control chip U1A determines whether the status is normal based on the output current direction and size feedback from the monitoring circuit, and if abnormal, shuts down the output function of the TEC controller U4.

[0011] Preferably, the model of the first adjustable resistor U2 is MCP4641T-503E / ML.

[0012] Preferably, the temperature feedback circuit includes a second adjustable resistor U3, a resistor R9, a resistor R8, a thermistor RT1, a resistor R10, a capacitor C5, an operational amplifier A3, a capacitor C2, a resistor R7, a capacitor C3, a resistor R6 and a capacitor C4, wherein the thermistor RT1 is a thermistor built into the laser, the eighth pin of the second adjustable resistor U3 is connected to the power supply V1, the sixth pin of the second adjustable resistor U3 is connected to one end of the resistor R9 and to the reference power supply VREF, the other end of the resistor R9 is connected to one end of the resistor R8, the other end of the resistor R8 is connected to the inverting terminal of the operational amplifier A3, the fifth pin of the second adjustable resistor U3 is connected to one end of the capacitor C5, the other end of the capacitor C5 is grounded, and one end of the capacitor C5 is connected to the thermistor RT1. 1, the other end of the thermistor RT1 is grounded, one end of the thermistor RT1 is connected to the non-inverting terminal of the operational amplifier A3, one end of the resistor R10 is connected to one end of the resistor R8, and the other end of the resistor R10 is grounded; the positive power supply terminal of the operational amplifier A3 is connected to the power supply V+, and the negative power supply terminal of the operational amplifier A3 is connected to the power supply V-; the inverting terminal of the operational amplifier A3 is connected to one end of the capacitor C2, the other end of the capacitor C2 is connected to one end of the resistor R7, the other end of the resistor R7 is connected to the pin CTLI of the TEC controller U4, one end of the capacitor C2 is connected to one end of the resistor R6, the other end of the resistor R6 is connected to one end of the capacitor C4, the other end of the capacitor C4 is grounded, one end of the capacitor C3 is connected to the output terminal of the operational amplifier A3, and the other end of the capacitor C3 is connected to one end of the resistor R6.

[0013] The reference power supply VREF is connected to ground via a second adjustable resistor U3 in series with the thermistor in the laser. The main control chip U1A sets the resistance of the second adjustable resistor U3 so that the voltages at the two input terminals of the operational amplifier A3 are the same under the target temperature conditions.

[0014] Preferably, the tenth pin of the main control chip U1A is connected to the output end of the comparator U1, the fifty-ninth pin, the sixtieth pin and the sixty-first pin of the main control chip U1A are respectively connected to the first pin, the second pin and the third pin of the first adjustable resistor U2, the thirty-third pin of the main control chip U1A is connected to the pin SHDN of the TEC controller U4, and the thirty-sixth pin, the thirty-fourth pin and the thirty-fifth pin of the main control chip U1A are respectively connected to the first pin, the second pin and the third pin of the second adjustable resistor U3.

[0015] Preferably, the model of the main control chip U1A is STM32L452RET6.

[0016] The present invention also provides a control method for a laser operating temperature control circuit, the method comprising: the main control chip U1A quickly adjusts the temperature by setting the resistance value of an adjustable resistor in a temperature feedback circuit, and at the same time, the main control chip U1A adjusts the maximum output current and potential difference of the current output end of the configuration circuit; the main control chip U1A also determines whether the state is normal based on the output current direction and magnitude fed back by the monitoring circuit, and if abnormal, shuts down the output function of the configuration circuit.

[0017] The advantages of the present invention are: the present invention connects the thermistor encapsulated in the laser to the temperature feedback circuit, and the main control chip U1A quickly adjusts the temperature by setting the resistance value of the adjustable resistor in the temperature feedback circuit. At the same time, the main control chip U1A adjusts the maximum output current and potential difference of the current output end of the configuration circuit. The main control chip U1A judges whether the state is normal based on the output current direction and size feedback from the monitoring circuit. If it is abnormal, the output function of the configuration circuit is turned off, thereby ensuring rapid temperature adjustment while ensuring stable output of a large current, solving the contradiction between the speed of temperature adjustment and the stability of adjustment. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A block diagram of a laser operating temperature control circuit disclosed in an embodiment of the present invention;

[0019] Figure 2 A schematic diagram of a monitoring circuit in a laser operating temperature control circuit disclosed in an embodiment of the present invention;

[0020] Figure 3 A schematic diagram of a configuration circuit in a laser operating temperature control circuit disclosed in an embodiment of the present invention;

[0021] Figure 4 A schematic diagram of a temperature feedback circuit in a laser operating temperature control circuit disclosed in an embodiment of the present invention;

[0022] Figure 5 This is a schematic diagram of a main control chip in a laser operating temperature control circuit disclosed in an embodiment of the present invention. DETAILED DESCRIPTION

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0024] like Figure 1As shown, a laser operating temperature control circuit includes a main control chip U1A, a monitoring circuit, a configuration circuit, a temperature feedback circuit, and a laser. The laser includes a built-in thermistor. The main control chip U1A is connected to the configuration circuit and the temperature feedback circuit respectively. The monitoring circuit is connected to the configuration circuit, and the configuration circuit is connected to the temperature feedback circuit. The temperature feedback circuit is connected to the thermistor built into the laser. The laser has an integrated cooling plate, which is connected to the configuration circuit.

[0025] like Figure 2 As shown, the monitoring circuit includes a resistor R3, a resistor R4, a resistor R2, a capacitor C1, an operational amplifier A1, an operational amplifier A2, a diode D1, a diode D2, a transistor Q1, a transistor Q2, a resistor R1 and a comparator U1. The model of the comparator U1 is OP27.

[0026] One end of the resistor R3 is connected to one end of the resistor R4, the other end of the resistor R4 is connected to one end of the capacitor C1, and the other end of the capacitor C1 is grounded; one end of the capacitor C1 is connected to one end of the resistor R2, and the other end of the resistor R2 is connected to the non-inverting end of the operational amplifier A2; the other end of the resistor R3 is connected to the non-inverting end of the operational amplifier A1, the inverting end of the operational amplifier A1 is connected to the collector of the transistor Q2, and the inverting end of the operational amplifier A2 is connected to the collector of the transistor Q1, the positive power supply terminal of the operational amplifier A1 and the positive power supply terminal of the operational amplifier A2 are both connected to the power supply V+, and the negative power supply terminal of the operational amplifier A1 and the negative power supply terminal of the operational amplifier A2 are both connected Power supply V-; the output terminal of operational amplifier A1 is connected to the anode of diode D1, the cathode of diode D1 is connected to the base of transistor Q1, the output terminal of operational amplifier A2 is connected to the anode of diode D2, the cathode of diode D2 is connected to the base of transistor Q2; the emitter of transistor Q1 is connected to the emitter of transistor Q2, one end of resistor R1 is connected to the emitter of transistor Q1, and the other end is connected to the ADC acquisition module; the inverting terminal of comparator U1 is connected to the output terminal of operational amplifier A1, the non-inverting terminal of comparator U1 is connected to the output terminal of operational amplifier A2, the positive power terminal of comparator U1 is connected to power supply V+, and the negative power terminal of comparator U1 is connected to power supply V-.

[0027] Pin ITEC of TEC controller U4 is connected in series with sampling resistor R4 and capacitor C1, then to ground. The two ends of sampling resistor R4 are connected to a differential amplifier circuit consisting of two op amps, A1 and A2. The outputs of the differential amplifier are connected to the inputs of comparator U1. The voltage level at the output of comparator U1 indicates the direction of the output current of TEC controller U4 (i.e., whether the current flows from the LXP terminal to the LXN terminal or vice versa). After the current flows through sampling resistor R1, the ADC acquisition module collects the voltage amplitude, tracking the output current of TEC controller U4 in real time.

[0028] like Figure 3 As shown, the configuration circuit includes a first adjustable resistor U2, a resistor R5, a TEC controller U4 and a capacitor C6. The model of the first adjustable resistor U2 is MCP4641T-503E / ML. The fourth pin of the first adjustable resistor U2 is grounded, the eighth pin of the first adjustable resistor U2 is connected to the power supply V1, the sixth pin of the first adjustable resistor U2 is connected to the pin MAXIN of the TEC controller U4, the fifth pin of the first adjustable resistor U2 is connected to the pin MAXV of the TEC controller U4, one end of the resistor R5 is connected to the fifth pin of the first adjustable resistor U2, and the other end of the resistor R5 is grounded; the pin MAXIN, the pin MAXIP and the pin VREF of the TEC controller U4 are all connected to the reference power supply VREF; the pin VDD of the TEC controller U4 is connected to the power supply V1, the pin GND of the TEC controller U4 is grounded, and the pin ITEC of the TEC controller U4 is connected to one end of the resistor R3; the pin LXP of the TEC controller U4 is connected to the positive pole of the cooling plate and the pin LXN of the TEC controller U4 is connected to the negative pole of the cooling plate, the cooling plate is a cooling plate integrated inside the laser, the pin COMP of the TEC controller U4 is connected to one end of the capacitor C6, and the other end of the capacitor C6 is grounded. The main control chip U1A adjusts the maximum output current and potential difference of the current output end of the TEC controller U4 by setting the resistance value of the first adjustable resistor U2; the main control chip U1A determines whether the status is normal based on the output current direction and size feedback from the monitoring circuit, and if abnormal, shuts down the output function of the TEC controller U4.

[0029] like Figure 4As shown, the temperature feedback circuit includes a second adjustable resistor U3, a resistor R9, a resistor R8, a thermistor RT1, a resistor R10, a capacitor C5, an operational amplifier A3, a capacitor C2, a resistor R7, a capacitor C3, a resistor R6 and a capacitor C4. The thermistor RT1 is a thermistor built into the laser. The eighth pin of the second adjustable resistor U3 is connected to the power supply V1, the sixth pin of the second adjustable resistor U3 is connected to one end of the resistor R9 and to the reference power supply VREF, the other end of the resistor R9 is connected to one end of the resistor R8, the other end of the resistor R8 is connected to the inverting terminal of the operational amplifier A3, the fifth pin of the second adjustable resistor U3 is connected to one end of the capacitor C5, the other end of the capacitor C5 is grounded, and one end of the capacitor C5 is connected to the thermistor RT1. 1, the other end of the thermistor RT1 is grounded, one end of the thermistor RT1 is connected to the non-inverting terminal of the operational amplifier A3, one end of the resistor R10 is connected to one end of the resistor R8, and the other end of the resistor R10 is grounded; the positive power supply terminal of the operational amplifier A3 is connected to the power supply V+, and the negative power supply terminal of the operational amplifier A3 is connected to the power supply V-; the inverting terminal of the operational amplifier A3 is connected to one end of the capacitor C2, the other end of the capacitor C2 is connected to one end of the resistor R7, the other end of the resistor R7 is connected to the pin CTLI of the TEC controller U4, one end of the capacitor C2 is connected to one end of the resistor R6, the other end of the resistor R6 is connected to one end of the capacitor C4, the other end of the capacitor C4 is grounded, one end of the capacitor C3 is connected to the output terminal of the operational amplifier A3, and the other end of the capacitor C3 is connected to one end of the resistor R6.

[0030] The reference power supply VREF is connected to ground via a second adjustable resistor U3 in series with the thermistor in the laser. The main control chip U1A sets the resistance of the second adjustable resistor U3 so that the voltages at the two input terminals of the operational amplifier A3 are the same under the target temperature conditions.

[0031] like Figure 5 As shown, the model of the main control chip U1A is STM32L452RET6. The tenth pin of the main control chip U1A is connected to the output end of the comparator U1, the fifty-ninth pin, the sixtieth pin and the sixty-first pin of the main control chip U1A are connected to the first pin, the second pin and the third pin of the first adjustable resistor U2 respectively, and the thirty-third pin of the main control chip U1A is connected to the pin of the TEC controller U4. The thirty-sixth pin, the thirty-fourth pin, and the thirty-fifth pin of the main control chip U1A are connected to the first pin, the second pin, and the third pin of the second adjustable resistor U3 respectively.

[0032] The present invention also provides a control method for a laser operating temperature control circuit, the method comprising: the main control chip U1A adjusts the maximum output current and potential difference of the current output end of the TEC controller U4 by setting the resistance value of the first adjustable resistor U2; the main control chip U1A determines whether the state is normal based on the output current direction and magnitude fed back by the monitoring circuit, and if abnormal, shuts down the output function of the TEC controller U4.

[0033] The reference power supply VREF is connected to ground via a second adjustable resistor U3 in series with the thermistor in the laser. The main control chip U1A sets the resistance of the second adjustable resistor U3 so that the voltages at the two input terminals of the operational amplifier A3 are the same under the target temperature conditions.

[0034] Pin ITEC of TEC controller U4 is connected in series with sampling resistor R4 and capacitor C1, then to ground. The two ends of sampling resistor R4 are connected to a differential amplifier circuit consisting of two op amps, A1 and A2. The outputs of the differential amplifier are connected to the inputs of comparator U1. The voltage level at the output of comparator U1 indicates the direction of the output current of TEC controller U4 (i.e., whether the current flows from the LXP terminal to the LXN terminal or vice versa). After the current flows through sampling resistor R1, the ADC acquisition module collects the voltage amplitude, tracking the output current of TEC controller U4 in real time.

[0035] The main control chip U1A quickly adjusts the temperature by setting the resistance value of the adjustable resistor in the temperature feedback circuit. At the same time, the main control chip U1A adjusts the maximum output current and potential difference of the current output end of the configuration circuit to ensure rapid temperature adjustment while ensuring a large output current, thus resolving the contradiction between the speed of temperature regulation and the stability of regulation.

[0036] Through the above technical solution, the present invention discloses a laser operating temperature control circuit and a control method thereof, which connects a thermistor encapsulated in the laser to a temperature feedback circuit. The main control chip U1A quickly adjusts the temperature by setting the resistance value of the adjustable resistor in the temperature feedback circuit. At the same time, the main control chip U1A adjusts the maximum output current and potential difference of the current output end of the configuration circuit. The main control chip U1A determines whether the state is normal based on the output current direction and size feedback from the monitoring circuit. If it is abnormal, the output function of the configuration circuit is turned off, thereby ensuring rapid temperature adjustment while ensuring a large output current, thereby resolving the contradiction between the speed of temperature adjustment and the stability of adjustment.

[0037] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A laser operating temperature control circuit, characterized in that: It includes a main control chip U1A, a monitoring circuit, a configuration circuit, a temperature feedback circuit and a laser. The laser includes a built-in thermistor. The main control chip U1A is connected to the configuration circuit and the temperature feedback circuit respectively. The monitoring circuit is connected to the configuration circuit, the configuration circuit is connected to the temperature feedback circuit, and the temperature feedback circuit is connected to the thermistor built into the laser. The main control chip U1A quickly adjusts the temperature by setting the resistance value of the adjustable resistor in the temperature feedback circuit. At the same time, the main control chip U1A adjusts the maximum output current and potential difference of the current output end of the configuration circuit. The main chip U1A also judges whether the state is normal according to the output current direction and size fed back by the monitoring circuit. If it is abnormal, the configuration circuit output function is turned off. The monitoring circuit includes a resistor R3, a resistor R4, a resistor R2, a capacitor C1, an operational amplifier A1, an operational amplifier A2, a diode D1, a diode D2, a transistor Q1, a transistor Q2, a resistor R1 and a comparator U1, one end of the resistor R3 is connected to one end of the resistor R4, the other end of the resistor R4 is connected to one end of the capacitor C1, and the other end of the capacitor C1 is grounded; one end of the capacitor C1 is connected to one end of the resistor R2, and the other end of the resistor R2 is connected to the non-inverting end of the operational amplifier A2; the other end of the resistor R3 is connected to the non-inverting end of the operational amplifier A1, the inverting end of the operational amplifier A1 is connected to the collector of the transistor Q2, the inverting end of the operational amplifier A2 is connected to the collector of the transistor Q1, and the collector of the operational amplifier A1 is connected to the inverting end of the transistor Q2. The positive terminal of the source and the positive terminal of the power supply of the operational amplifier A2 are both connected to the power supply V+, and the negative terminal of the power supply of the operational amplifier A1 and the negative terminal of the power supply of the operational amplifier A2 are both connected to the power supply V-; the output terminal of the operational amplifier A1 is connected to the positive terminal of the diode D1, and the negative terminal of the diode D1 is connected to the base of the transistor Q1. The output terminal of the operational amplifier A2 is connected to the positive terminal of the diode D2, and the negative terminal of the diode D2 is connected to the base of the transistor Q2; the emitter of the transistor Q1 is connected to the emitter of the transistor Q2, one end of the resistor R1 is connected to the emitter of the transistor Q1, and the other end is connected to the ADC acquisition module; the inverting terminal of the comparator U1 is connected to the output terminal of the operational amplifier A1, the non-inverting terminal of the comparator U1 is connected to the output terminal of the operational amplifier A2, and the positive terminal of the power supply of the comparator U1 connected to power supply V+, and the negative power terminal of the comparator U1 is connected to power supply V-; the configuration circuit includes a first adjustable resistor U2, a resistor R5, a TEC controller U4 and a capacitor C6, the fourth pin of the first adjustable resistor U2 is grounded, the eighth pin of the first adjustable resistor U2 is connected to power supply V1, the sixth pin of the first adjustable resistor U2 is connected to pin MAXIN of the TEC controller U4, the fifth pin of the first adjustable resistor U2 is connected to pin MAXV of the TEC controller U4, one end of the resistor R5 is connected to the fifth pin of the first adjustable resistor U2, and the other end of the resistor R5 is grounded; pins MAXIN, MAXIP and VREF of the TEC controller U4 are all connected to a reference power supply VREF;Pin VDD of TEC controller U4 is connected to power supply V1, pin GND of TEC controller U4 is grounded, and pin ITEC of TEC controller U4 is connected to one end of resistor R3; pin LXP of TEC controller U4 is connected to the positive electrode of a cooling plate, and pin LXN of TEC controller U4 is connected to the negative electrode of the cooling plate. The cooling plate is an integrated cooling plate inside the laser. Pin COMP of TEC controller U4 is connected to one end of capacitor C6, and the other end of capacitor C6 is grounded.

2. A laser operating temperature control circuit according to claim 1, characterized in that: A cooling plate is integrated inside the laser, and the cooling plate is connected to the configuration circuit.

3. The laser operating temperature control circuit according to claim 1, characterized in that: The model of the comparator U1 is OP27.

4. The laser operating temperature control circuit according to claim 1, characterized in that: The model of the first adjustable resistor U2 is MCP4641T-503E / ML.

5. The laser operating temperature control circuit according to claim 1, characterized in that: The temperature feedback circuit includes a second adjustable resistor U3, a resistor R9, a resistor R8, a thermistor RT1, a resistor R10, a capacitor C5, an operational amplifier A3, a capacitor C2, a resistor R7, a capacitor C3, a resistor R6 and a capacitor C4. The thermistor RT1 is a thermistor built into the laser. The eighth pin of the second adjustable resistor U3 is connected to the power supply V1, the sixth pin of the second adjustable resistor U3 is connected to one end of the resistor R9 and to the reference power supply VREF, the other end of the resistor R9 is connected to one end of the resistor R8, the other end of the resistor R8 is connected to the inverting end of the operational amplifier A3, the fifth pin of the second adjustable resistor U3 is connected to one end of the capacitor C5, the other end of the capacitor C5 is grounded, and one end of the capacitor C5 is connected to the inverting end of the thermistor RT1. One end of the thermistor RT1 is connected to the non-inverting end of the operational amplifier A3, one end of the resistor R10 is connected to one end of the resistor R8, and the other end of the resistor R10 is grounded; the positive power supply end of the operational amplifier A3 is connected to the power supply V+, and the negative power supply end of the operational amplifier A3 is connected to the power supply V-; the inverting end of the operational amplifier A3 is connected to one end of the capacitor C2, the other end of the capacitor C2 is connected to one end of the resistor R7, the other end of the resistor R7 is connected to the pin CTLI of the TEC controller U4, one end of the capacitor C2 is connected to one end of the resistor R6, the other end of the resistor R6 is connected to one end of the capacitor C4, the other end of the capacitor C4 is grounded, one end of the capacitor C3 is connected to the output end of the operational amplifier A3, and the other end of the capacitor C3 is connected to one end of the resistor R6.

6. The laser operating temperature control circuit according to claim 5, characterized in that: The tenth pin of the main control chip U1A is connected to the output end of the comparator U1, the fifty-ninth pin, the sixtieth pin and the sixty-first pin of the main control chip U1A are respectively connected to the first pin, the second pin and the third pin of the first adjustable resistor U2, the thirty-third pin of the main control chip U1A is connected to the SHDN pin of the TEC controller U4, and the thirty-sixth pin, the thirty-fourth pin and the thirty-fifth pin of the main control chip U1A are respectively connected to the first pin, the second pin and the third pin of the second adjustable resistor U3.

7. The laser operating temperature control circuit according to claim 6, characterized in that: The model of the main control chip U1A is STM32L452RET6.

8. The method for controlling a laser operating temperature control circuit according to any one of claims 1 to 7, characterized in that: The method includes: the main control chip U1A quickly adjusts the temperature by setting the resistance value of the adjustable resistor in the temperature feedback circuit, and at the same time, the main control chip U1A adjusts the maximum output current and potential difference of the current output end of the configuration circuit; the main control chip U1A also determines whether the status is normal based on the output current direction and size fed back by the monitoring circuit, and if abnormal, shuts down the output function of the configuration circuit.

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