A spaceflight semiconductor laser aging and life test system

Abstract

A kind of semiconductor laser of space navigation is worn out and life test system of examination, including: control machine case, heat dissipation heat sink and current compensation module;When carrying out wear and life test, semiconductor laser is located in the inside of temperature box;Control machine case provides driving current to the input end of semiconductor laser based on preset test current value;At the same time, control machine case carries out real-time temperature compensation to semiconductor laser after the temperature in temperature box is stable, so that the temperature of semiconductor laser is always at preset test temperature;Current compensation module real-time acquisition driving current of the input end of semiconductor laser, and based on the current of acquisition current compensation difference value;Control machine case is based on current compensation difference value compensation driving current currently provided to the input end of semiconductor laser, to avoid the precision of current provided to semiconductor laser by circuit loss influence;Heat dissipation heat sink is used to homogenize the local hot spot of semiconductor laser and carry out heat dissipation.

Description

Technical Field

[0001] This invention relates to an aging and lifespan assessment test system for aerospace semiconductor lasers, belonging to the field of electronic circuits and their control technology. Background Technology

[0002] Aging and lifespan assessment tests for aerospace semiconductor lasers are a crucial part of performance evaluation before their application in aerospace environments. These tests screen and verify whether the corresponding semiconductor laser devices can meet the high reliability and long lifespan requirements of aerospace applications. However, existing semiconductor laser assessment systems are susceptible to external environmental factors and circuit losses during testing, making it difficult to maintain stable test temperatures and currents, thus affecting the accuracy of aging and lifespan assessments. Furthermore, existing assessment systems can only test single-model semiconductor lasers, resulting in poor versatility. Summary of the Invention

[0003] The technical problem solved by this invention is to overcome the shortcomings of existing technologies and provide a aging and lifespan assessment test system for aerospace semiconductor lasers. This system controls and compensates for the real-time temperature of the semiconductor laser through a control chassis, compensates for the input current of the semiconductor laser through a current compensation module, and employs different pin connection methods for different models of semiconductor lasers, thus solving the problems of low testing accuracy and poor versatility in existing semiconductor laser assessment test systems. The technical solution of this invention is: An aging and lifespan assessment test system for aerospace semiconductor lasers includes: a control chassis, a heat sink, and a current compensation module; During aging and lifespan testing, the semiconductor laser is located inside the chamber, and the control chassis is electrically connected to the heat sink. When the semiconductor laser is an N-type semiconductor laser, the pins of the heat sink are connected to the semiconductor laser via an N-type connection. When the semiconductor laser is an S-type semiconductor laser, the pins of the heat sink are connected to the semiconductor laser via an S-type connection. The heat sink is used to homogenize local hot spots of the semiconductor laser and dissipate heat to simulate the actual working conditions of the semiconductor laser. During aging and lifespan testing, the control chassis generates a drive current based on a preset test current value. The drive current is transferred to the input end of the semiconductor laser through the heat sink to drive the semiconductor laser to work. At the same time, after the temperature inside the chamber stabilizes, the control chassis performs real-time temperature compensation for the semiconductor laser to keep the internal temperature of the semiconductor laser at the preset test temperature. The current compensation module contains a current mapping model. The input of the current mapping model is the actual drive current at the input terminal of the semiconductor laser, and the output is the preset test current value on which the control chassis generates the actual drive current. During aging and lifespan testing, the current compensation module collects the actual drive current at the input terminal of the semiconductor laser in real time. Based on the actual drive current and the current mapping model, the current compensation module calculates the current compensation difference. The control chassis adjusts the drive current currently supplied to the input terminal of the semiconductor laser based on the current compensation difference to avoid circuit losses affecting the accuracy of the current supplied to the semiconductor laser.

[0004] Furthermore, the control chassis includes a power supply unit, a control unit, a drive unit, and a temperature control unit; The power supply unit provides power to the control unit, drive unit, and temperature control unit; The control unit controls the drive unit to generate a corresponding drive current based on a preset test current value; the drive unit sends the generated drive current to the heat sink, and the heat sink transmits the drive current to the input end of the semiconductor laser, driving the semiconductor laser to start working. The temperature control unit provides excitation current to the cooler of the semiconductor laser and simultaneously collects the internal temperature of the semiconductor laser in real time, transmitting the collected temperature to the control unit. The control unit compares the collected temperature with the preset test temperature and adjusts the excitation current provided by the temperature control unit to the cooler based on the temperature comparison result, thereby achieving temperature compensation of the semiconductor laser and keeping the temperature of the semiconductor laser at the preset test temperature.

[0005] Furthermore, the control unit adjusts the excitation current provided to the cooler by the temperature control unit based on the temperature comparison results as follows: when the collected temperature is lower than the preset test temperature, the control unit controls the temperature control unit to provide a reverse excitation current to the cooler, so that the cooler is in a heating state to increase the internal temperature of the semiconductor laser; the magnitude of the provided reverse excitation current is calculated by the control unit based on the temperature comparison results using a PID algorithm. When the collected temperature is higher than the preset test temperature, the control unit controls the temperature control unit to provide a positive excitation current to the cooler, so that the cooler is in a cooling state to reduce the internal temperature of the semiconductor laser; the magnitude of the provided positive excitation current is calculated by the control unit based on the temperature comparison results through a PID algorithm.

[0006] Furthermore, the testing system also includes a PC; the PC is connected to the control unit in the control chassis via a gigabit Ethernet port. The tester inputs the preset test current value and preset test temperature into the PC. After input, the PC transmits the preset test current value and preset test temperature to the control unit. At the same time, the control unit transmits the temperature collected by the temperature control unit to the PC. The PC displays the temperature collected by the temperature control unit for the tester to view.

[0007] Furthermore, the driving unit includes an MCU, a driving analog-to-digital converter, a driving operational amplifier, a driving digital-to-analog converter, and a laser driving circuit; The power supply unit provides analog current to the drive unit; the drive analog-to-digital converter converts the analog current provided by the power supply unit into digital drive current; the digital drive current enters the drive operational amplifier, which amplifies the digital drive current to obtain the amplified digital drive current; the control unit sends a control signal corresponding to the preset drive current value to the MCU based on the preset drive current value; after receiving the control signal, the MCU adjusts the amplified digital drive current to the corresponding digital drive current value; the digital drive current enters the drive digital-to-analog converter and is converted into analog drive current; finally, the laser drive circuit converts the analog drive current back into drive current and delivers it to the heat sink. The temperature control unit includes an MCU, a temperature control analog-to-digital converter, a temperature control operational amplifier, a temperature control digital-to-analog converter, and a laser temperature control circuit; The power supply unit provides analog current to the temperature control unit; the temperature control analog-to-digital converter converts the analog current provided by the power supply unit into a temperature control digital current; the temperature control digital current enters the temperature control operational amplifier, which amplifies the temperature control digital current to obtain a temperature control amplified digital current; based on the temperature comparison result, the control unit sends the control signal corresponding to the temperature comparison result to the MCU; after receiving the control signal, the MCU adjusts the temperature control amplified digital current to the temperature control drive digital current corresponding to the temperature comparison result; the temperature control drive digital current enters the temperature control digital-to-analog converter and is converted into a temperature control analog current; finally, the laser temperature control circuit converts the temperature control analog current into an excitation current and supplies it to the cooler of the semiconductor laser.

[0008] Furthermore, the current compensation module includes a current acquisition circuit and a current compensation calculation unit; The current acquisition circuit acquires the actual driving current at the input end of the semiconductor laser in real time and transmits the acquired actual driving current to the current compensation calculation unit; the current compensation calculation unit has a current mapping model in memory; the current compensation calculation unit calculates the current compensation difference based on the current mapping model and the actual driving current; The steps for constructing a current mapping model are as follows: The first step is to instruct the control chassis to generate drive currents according to multiple preset test current values. Each drive current is transferred to the input end of the semiconductor laser through a heat sink. The second step is to measure the actual drive current at the input of the semiconductor laser under each drive current. The third step is to fit the relationship expression between the actual driving current and the preset test current value using the Newton interpolation polynomial fitting method, thereby obtaining the current mapping model.

[0009] Furthermore, the specific process by which the current compensation calculation unit calculates the current compensation difference is as follows: The first step is for the current compensation module to input the actual driving current of the semiconductor laser into the current mapping model to obtain the preset test current value corresponding to the actual driving current. The second step is to calculate the initial current compensation difference I, using the following formula: I = |I1 - I2| / 2 Where I1 is the actual driving current and I2 is the preset test current value output by the current mapping model; The third step is to determine whether the initial current compensation difference is greater than the preset difference threshold. If the current compensation difference is greater than the preset difference threshold, the initial current compensation difference is used as the final current compensation difference; otherwise, the final current compensation difference is set to 0. Furthermore, the control chassis adjusts the driving current supplied to the semiconductor laser input based on the current compensation difference as follows: when the actual driving current I1 is less than the preset test current value I2 output by the current mapping model, the adjusted driving current I3 generated by the control chassis is: I3=I'+I When the actual drive current I1 is greater than the preset test current value I2 output by the current mapping model, the adjusted drive current I3 generated by the control chassis is: I3=I'-I Where I' is the drive current currently supplied by the control chassis to the input terminal of the semiconductor laser.

[0010] Furthermore, the heat sink includes a heat sink plate and a clamp; the clamp is used to fix the semiconductor laser on the heat sink plate; the heat sink plate is used to homogenize local hot spots of the semiconductor laser and dissipate heat; the clamp is connected to the control chassis via a cable; the clamp is provided with pins for connecting to pins on the semiconductor laser.

[0011] Furthermore, when the semiconductor laser is an N-type semiconductor laser, the pin connection between the heat sink and the semiconductor laser adopts an N-type connection method, specifically as follows: The anode of the cooler on the heat sink is connected to the anode of the cooler of the N-type semiconductor laser; the first thermistor electrode on the heat sink is connected to the first thermistor electrode of the N-type semiconductor laser; the anode of the detector on the heat sink is connected to the anode of the detector of the N-type semiconductor laser; the cathode of the detector on the heat sink is connected to the cathode of the detector of the N-type semiconductor laser; the second thermistor electrode on the heat sink is connected to the second thermistor electrode of the N-type semiconductor laser; the anode of the laser diode chip on the heat sink is connected to the anode of the laser diode chip of the N-type semiconductor laser; the cathode of the laser diode chip on the heat sink is connected to the cathode of the laser diode of the N-type semiconductor laser; the cathode of the cooler on the heat sink is connected to the cathode of the cooler of the N-type semiconductor laser; the first, second, third, fourth, fifth, and sixth unused pins on the heat sink are respectively connected to the first, second, third, fourth, fifth, and sixth unused pins of the N-type semiconductor laser. When the semiconductor laser is an S-type semiconductor laser, the heat sink and the pins of the semiconductor laser are connected in an S-type configuration, specifically as follows: The anode of the cooler on the heat sink is connected to the anode of the cooler of the S-type semiconductor laser; the first thermistor electrode on the heat sink is connected to the first thermistor electrode of the S-type semiconductor laser; the anode of the detector on the heat sink is connected to the anode of the detector of the S-type semiconductor laser; the cathode of the detector on the heat sink is connected to the cathode of the detector of the S-type semiconductor laser; the second thermistor electrode on the heat sink is connected to the second thermistor electrode of the S-type semiconductor laser; the anode of the laser diode chip on the heat sink is connected to the anode of the laser diode chip of the S-type semiconductor laser; the cathode of the laser diode chip on the heat sink is connected to the cathode of the laser diode chip of the S-type semiconductor laser; the cathode of the semiconductor cooler on the heat sink is connected to the cathode of the cooler of the S-type semiconductor laser; the first, second, third, fifth, and sixth unused pins on the heat sink are respectively connected to the first, second, third, fourth, and fifth unused pins of the S-type semiconductor laser.

[0012] Secondly, this invention also proposes a test method for aging and lifespan assessment of aerospace semiconductor lasers. This test method is based on the aforementioned test system for aging and lifespan assessment of aerospace semiconductor lasers, and the specific steps are as follows: (1) Place the semiconductor laser inside the temperature chamber; the heat sink is connected to the semiconductor laser through pins, and the control chassis is connected to the heat sink through cables; (2) Start the control box; the control box generates a drive current based on the preset test current value; the drive current is transferred to the input end of the semiconductor laser through the heat sink to drive the semiconductor laser to work; (3) Activate the heat sink to homogenize the local hot spots of the semiconductor laser and dissipate heat; (4) Start the current compensation module to collect the drive current at the input end of the semiconductor laser in real time, and perform curve fitting on all the collected drive currents at preset intervals to obtain the drive current fitting result; the current compensation module calculates the current compensation difference based on the drive current fitting result and the preset test current value; the control box adjusts the drive current currently supplied to the input end of the semiconductor laser based on the current compensation difference to avoid circuit loss affecting the accuracy of the current supplied to the semiconductor laser. (5) Start the temperature chamber and slowly raise the temperature of the temperature chamber from low to high. During the process of adjusting the temperature of the temperature chamber, monitor the internal temperature of the semiconductor laser in real time. When the internal temperature of the semiconductor laser reaches the preset test temperature, stop adjusting the temperature of the temperature chamber. (6) Maintain the temperature of the chamber to the preset test time; throughout the process, control the chamber to perform real-time temperature compensation for the semiconductor laser so that the internal temperature of the semiconductor laser remains at the preset test temperature. (7) After the preset test time is reached, close the temperature chamber, control box and heat sink, and remove the semiconductor laser from the temperature chamber; (8) Test whether the semiconductor laser can work normally; if the semiconductor laser can work normally, the semiconductor laser passes the aging and life test; otherwise, the semiconductor laser fails the aging and life test.

[0013] The advantages of this invention compared to the prior art are: (1) The present invention controls the temperature of the semiconductor laser in real time by controlling the chassis to ensure that the temperature of the semiconductor laser is always at the preset test temperature, thus ensuring the accuracy of the aging and life test of the semiconductor laser.

[0014] (2) The present invention uses a current compensation module to perform curve fitting on the input current of the semiconductor laser, and calculates the current compensation difference based on the curve fitting result, thereby compensating the input current of the semiconductor laser, which further ensures the accuracy of the system in the test.

[0015] (3) The present invention connects and fixes different types of semiconductor lasers through different pin connection methods, thereby realizing the testing of N-type semiconductor lasers and S-type semiconductor lasers and improving the versatility of the system. Attached Figure Description

[0016] Figure 1This is a block diagram of an aging and lifespan assessment test system for aerospace semiconductor lasers according to the present invention; Figure 2 This is a schematic diagram of the composition of an aging and life assessment test system for aerospace semiconductor lasers according to the present invention; Figure 3 This is a schematic diagram of the connection principle of the laser driving circuit and the laser temperature control circuit in an aerospace semiconductor laser aging and life assessment test system of the present invention. Figure 4 This is a pin connection diagram for the N-type and S-type connection methods in this invention. Detailed Implementation

[0017] The specific embodiments of the present invention will now be described in further detail with reference to the accompanying drawings.

[0018] like Figure 1 As shown, the present invention provides an aging and lifespan assessment test system for aerospace semiconductor lasers, comprising: a control chassis, a heat sink, and a current compensation module; During aging and lifespan testing, the semiconductor laser is located inside the chamber, and the control chassis is electrically connected to the heat sink. When the semiconductor laser is an N-type semiconductor laser, the pins of the heat sink are connected to the semiconductor laser via an N-type connection. When the semiconductor laser is an S-type semiconductor laser, the pins of the heat sink are connected to the semiconductor laser via an S-type connection. The heat sink is used to homogenize local hot spots of the semiconductor laser and dissipate heat to simulate the actual working conditions of the semiconductor laser. During aging and lifespan testing, the control chassis generates a drive current based on a preset test current value. The drive current is transferred to the input end of the semiconductor laser through the heat sink to drive the semiconductor laser to work. At the same time, after the temperature inside the chamber stabilizes, the control chassis performs real-time temperature compensation for the semiconductor laser to keep the internal temperature of the semiconductor laser at the preset test temperature. The current compensation module contains a current mapping model. The input of the current mapping model is the actual drive current at the input terminal of the semiconductor laser, and the output is the preset test current value on which the control chassis generates the actual drive current. During aging and lifespan testing, the current compensation module collects the actual drive current at the input terminal of the semiconductor laser in real time. Based on the actual drive current and the current mapping model, the current compensation module calculates the current compensation difference. The control chassis adjusts the drive current currently supplied to the input terminal of the semiconductor laser based on the current compensation difference to avoid circuit losses affecting the accuracy of the current supplied to the semiconductor laser.

[0019] Furthermore, the overall system connection configuration is as follows: Figure 2As shown, the current compensation module is installed inside the control box. The control box is connected to the heat sink via a cable with a length of 2m ± 0.1m and the resistance of each wire in the cable is ≤35mΩ. Furthermore, the control chassis includes a power supply unit, a control unit, a drive unit, and a temperature control unit; The power supply unit provides power to the control unit, drive unit, and temperature control unit; The control unit controls the drive unit to generate a corresponding drive current based on a preset test current value; the drive unit sends the generated drive current to the heat sink, and the heat sink transmits the drive current to the input end of the semiconductor laser, driving the semiconductor laser to start working. The temperature control unit provides excitation current to the cooler of the semiconductor laser and simultaneously collects the internal temperature of the semiconductor laser in real time, transmitting the collected temperature to the control unit. The control unit compares the collected temperature with the preset test temperature and adjusts the excitation current provided by the temperature control unit to the cooler based on the temperature comparison result, thereby achieving temperature compensation of the semiconductor laser and keeping the temperature of the semiconductor laser at the preset test temperature.

[0020] The control unit is connected to the drive unit and the temperature control unit via an RS485 serial port.

[0021] Furthermore, the control unit adjusts the excitation current provided to the cooler by the temperature control unit based on the temperature comparison results as follows: when the collected temperature is lower than the preset test temperature, the control unit controls the temperature control unit to provide a reverse excitation current to the cooler, so that the cooler is in a heating state to increase the internal temperature of the semiconductor laser; the magnitude of the provided reverse excitation current is calculated by the control unit based on the temperature comparison results using a PID algorithm. When the collected temperature is higher than the preset test temperature, the control unit controls the temperature control unit to provide a positive excitation current to the cooler, so that the cooler is in a cooling state to reduce the internal temperature of the semiconductor laser; the magnitude of the provided positive excitation current is calculated by the control unit based on the temperature comparison results through a PID algorithm.

[0022] Furthermore, the testing system also includes a PC; the PC is connected to the control unit in the control chassis via a gigabit Ethernet port. The tester inputs the preset test current value and preset test temperature into the PC. After input, the PC transmits the preset test current value and preset test temperature to the control unit. At the same time, the control unit transmits the temperature collected by the temperature control unit to the PC. The PC displays the temperature collected by the temperature control unit for the tester to view.

[0023] Furthermore, the driving unit includes an MCU, a driving analog-to-digital converter, a driving operational amplifier, a driving digital-to-analog converter, and a laser driving circuit; The power supply unit provides analog current to the drive unit; the drive analog-to-digital converter converts the analog current provided by the power supply unit into digital drive current; the digital drive current enters the drive operational amplifier, which amplifies the digital drive current to obtain the amplified digital drive current; the control unit sends a control signal corresponding to the preset drive current value to the MCU; after receiving the control signal, the MCU adjusts the amplified digital drive current to the corresponding digital drive current value; the digital drive current enters the drive digital-to-analog converter and is converted into analog drive current; finally, the laser drive circuit converts the analog drive current back into drive current and supplies it to the heat sink; the schematic diagram of the laser drive circuit is shown below. Figure 3 As shown; The temperature control unit includes an MCU, a temperature control analog-to-digital converter, a temperature control operational amplifier, a temperature control digital-to-analog converter, and a laser temperature control circuit; The power supply unit provides analog current to the temperature control unit; the temperature control analog-to-digital converter converts the analog current from the power supply unit into a temperature control digital current; the temperature control digital current enters the temperature control operational amplifier, which amplifies the temperature control digital current to obtain a temperature control amplified digital current; based on the temperature comparison result, the control unit sends a control signal corresponding to the temperature comparison result to the MCU; after receiving the control signal, the MCU adjusts the temperature control amplified digital current to the temperature control drive digital current corresponding to the temperature comparison result; the temperature control drive digital current enters the temperature control digital-to-analog converter and is converted into a temperature control analog current; finally, the laser temperature control circuit converts the temperature control analog current into an excitation current and supplies it to the cooler of the semiconductor laser; the schematic diagram of the laser temperature control circuit is shown below. Figure 3 As shown.

[0024] Furthermore, the output offset voltage of the driving operational amplifier and the temperature-controlled operational amplifier is ≤3µV, and the offset drift is ≤30nV / °C. The sampling resistors of the driving operational amplifier and the temperature-controlled operational amplifier are made of low-temperature drift materials such as manganese copper alloy, and a four-terminal connection is used to eliminate the resistance error brought in by the leads.

[0025] Furthermore, the current compensation module includes a current acquisition circuit and a current compensation calculation unit; The current acquisition circuit acquires the actual driving current at the input end of the semiconductor laser in real time and transmits the acquired actual driving current to the current compensation calculation unit; the current compensation calculation unit has a current mapping model in memory; the current compensation calculation unit calculates the current compensation difference based on the current mapping model and the actual driving current; The steps for constructing a current mapping model are as follows: The first step is to instruct the control chassis to generate drive currents according to multiple preset test current values. Each drive current is transferred to the input end of the semiconductor laser through a heat sink. The second step is to measure the actual drive current at the input of the semiconductor laser under each drive current. The third step is to fit the relationship expression between the actual driving current and the preset test current value using the Newton interpolation polynomial fitting method, thereby obtaining the current mapping model.

[0026] Furthermore, the specific process by which the current compensation calculation unit calculates the current compensation difference is as follows: The first step is for the current compensation module to input the actual driving current of the semiconductor laser into the current mapping model to obtain the preset test current value corresponding to the actual driving current. The second step is to calculate the initial current compensation difference I, using the following formula: I = |I1 - I2| / 2 Where I1 is the actual driving current and I2 is the preset test current value output by the current mapping model; The third step is to determine whether the initial current compensation difference is greater than the preset difference threshold. If the current compensation difference is greater than the preset difference threshold, the initial current compensation difference is used as the final current compensation difference; otherwise, the final current compensation difference is set to 0. Furthermore, the control chassis adjusts the driving current supplied to the semiconductor laser input based on the current compensation difference as follows: when the actual driving current I1 is less than the preset test current value I2 output by the current mapping model, the adjusted driving current I3 generated by the control chassis is: I3=I'+I When the actual drive current I1 is greater than the preset test current value I2 output by the current mapping model, the adjusted drive current I3 generated by the control chassis is: I3=I'-I Where I' is the drive current currently supplied by the control chassis to the input terminal of the semiconductor laser.

[0027] Furthermore, the heat sink includes a heat sink plate and a clamp; the clamp is used to fix the semiconductor laser on the heat sink plate; the heat sink plate is used to homogenize local hot spots of the semiconductor laser and dissipate heat; the clamp is connected to the control chassis via a cable; the clamp is provided with pins for connecting to pins on the semiconductor laser.

[0028] Furthermore, the heat sink is an aluminum plate.

[0029] Furthermore, the testing system has two heat sinks; one heat sink is used for local hot spot homogenization and heat dissipation for the N-type semiconductor laser, and the other heat sink is used for local hot spot homogenization and heat dissipation for the S-type semiconductor laser; the area of ​​the heat sink plate of each heat sink is larger than the area of ​​the semiconductor laser, thereby fixing multiple semiconductor lasers on the heat sink plate; each semiconductor laser is equipped with a control chassis, thereby enabling multiple semiconductor lasers to undergo aging and lifespan testing simultaneously.

[0030] Furthermore, when the semiconductor laser is an N-type semiconductor laser, the heat sink and the pins of the semiconductor laser are connected in an N-type configuration, such as... Figure 4 As shown in (a), specifically: The anode pin 1 of the cooler on the heat sink is connected to the anode pin 1 of the cooler in the N-type semiconductor laser; the first thermistor electrode pin 2 on the heat sink is connected to the first thermistor electrode pin 2 of the N-type semiconductor laser; the anode pin 3 of the detector on the heat sink is connected to the anode pin 3 of the detector in the N-type semiconductor laser; the cathode pin 4 of the detector on the heat sink is connected to the cathode pin 4 of the detector in the N-type semiconductor laser; the second thermistor electrode pin 5 on the heat sink is connected to the second thermistor electrode pin 5 of the N-type semiconductor laser; and the anode pin 10 of the laser diode chip on the heat sink is connected to the anode pin 10 of the laser diode chip in the N-type semiconductor laser. The cathode pin 11 of the laser diode chip on the heat sink is connected to the cathode pin 11 of the laser diode of the N-type semiconductor laser; the cathode pin 14 of the cooler on the heat sink is connected to the cathode pin 14 of the cooler of the N-type semiconductor laser; the first unused pin 6, the second unused pin 7, the third unused pin 8, the fourth unused pin 9, the fifth unused pin 12, and the sixth unused pin 13 on the heat sink are respectively connected to the first unused pin 6, the second unused pin 7, the third unused pin 8, the fourth unused pin 9, the fifth unused pin 12, and the sixth unused pin 13 of the N-type semiconductor laser; When the semiconductor laser is an S-type semiconductor laser, the heat sink and the pins of the semiconductor laser are connected in an S-type configuration, such as... Figure 4 As shown in (b), specifically: The anode pin 1 of the cooler on the heat sink is connected to the anode pin 6 of the cooler of the S-type semiconductor laser; the first thermistor electrode pin 2 on the heat sink is connected to the first thermistor electrode pin 1 of the S-type semiconductor laser; the anode pin 3 of the detector on the heat sink is connected to the anode pin 4 of the detector of the S-type semiconductor laser; the cathode pin 4 of the detector on the heat sink is connected to the cathode pin 5 of the detector of the S-type semiconductor laser; the second thermistor electrode pin 5 on the heat sink is connected to the second thermistor electrode pin 2 of the S-type semiconductor laser; and the anode pin 10 of the laser diode chip on the heat sink is connected to the laser diode chip of the S-type semiconductor laser. Anode pin 11 is connected; cathode pin 11 of the laser diode chip on the heat sink is connected to cathode pin 12 of the laser diode chip of the S-type semiconductor laser; cathode pin 14 of the semiconductor cooler on the heat sink is connected to cathode pin 7 of the cooler of the S-type semiconductor laser; the first unused pin 6, the second unused pin 7, the third unused pin 8, the fifth unused pin 12 and the sixth unused pin 13 on the heat sink are respectively connected to the first unused pin 8, the second unused pin 9, the third unused pin 10, the fourth unused pin 13 and the fifth unused pin 14 of the S-type semiconductor laser.

[0031] This invention connects and fixes different types of semiconductor lasers using different pin connection methods, thereby enabling the testing of N-type and S-type semiconductor lasers and improving the system's versatility.

[0032] In summary, this invention controls the temperature of the semiconductor laser in real time by adjusting and compensating the temperature of the control chassis, thereby ensuring that the temperature of the semiconductor laser is always at the preset test temperature, thus guaranteeing the accuracy of the semiconductor laser aging and lifespan assessment. Simultaneously, this invention uses a current compensation module to perform curve fitting on the input current of the semiconductor laser, and calculates the current compensation difference based on the curve fitting results, thereby compensating the input current of the semiconductor laser and further ensuring the accuracy of the system's assessment.

[0033] Secondly, this invention also proposes a test method for aging and lifespan assessment of aerospace semiconductor lasers. This test method is based on the aforementioned test system for aging and lifespan assessment of aerospace semiconductor lasers, and the specific steps are as follows: (1) Place the semiconductor laser inside the temperature chamber; the heat sink is connected to the semiconductor laser through pins, and the control chassis is connected to the heat sink through cables; (2) Start the control box; the control box generates a drive current based on the preset test current value; the drive current is transferred to the input end of the semiconductor laser through the heat sink to drive the semiconductor laser to work; (3) Activate the heat sink to homogenize the local hot spots of the semiconductor laser and dissipate heat; (4) Start the current compensation module to collect the drive current at the input end of the semiconductor laser in real time, and perform curve fitting on all the collected drive currents at preset intervals to obtain the drive current fitting result; the current compensation module calculates the current compensation difference based on the drive current fitting result and the preset test current value; the control box adjusts the drive current currently supplied to the input end of the semiconductor laser based on the current compensation difference to avoid circuit loss affecting the accuracy of the current supplied to the semiconductor laser. (5) Start the temperature chamber and slowly raise the temperature of the temperature chamber from low to high. During the process of adjusting the temperature of the temperature chamber, monitor the internal temperature of the semiconductor laser in real time. When the internal temperature of the semiconductor laser reaches the preset test temperature, stop adjusting the temperature of the temperature chamber. (6) Maintain the temperature of the chamber to the preset test time; throughout the process, control the chamber to perform real-time temperature compensation for the semiconductor laser so that the internal temperature of the semiconductor laser remains at the preset test temperature. (7) After the preset test time is reached, close the temperature chamber, control box and heat sink, and remove the semiconductor laser from the temperature chamber; (8) Test whether the semiconductor laser can work normally; if the semiconductor laser can work normally, the semiconductor laser passes the aging and life test; otherwise, the semiconductor laser fails the aging and life test.

[0034] The parts of this invention not described in detail are common knowledge to those skilled in the art.

Claims

1. A test system for aging and lifespan assessment of aerospace semiconductor lasers, characterized in that, include: Control chassis, heat sink, and current compensation module; During aging and life testing, the semiconductor laser is located inside the temperature chamber, and there is an electrical connection between the control chassis and the heat sink. When the semiconductor laser is an N-type semiconductor laser, the pins of the heat sink are connected to the semiconductor laser via an N-type connection; when the semiconductor laser is an S-type semiconductor laser, the pins of the heat sink are connected to the semiconductor laser via an S-type connection; the heat sink is used to homogenize local hot spots of the semiconductor laser and dissipate heat to simulate the actual working conditions of the semiconductor laser. During aging and life testing, the control chassis generates a drive current based on a preset test current value; The driving current is transferred to the input end of the semiconductor laser through the heat sink to drive the semiconductor laser to work; at the same time, after the temperature inside the control chamber stabilizes, the semiconductor laser is subjected to real-time temperature compensation so that the internal temperature of the semiconductor laser is always at the preset test temperature. The current compensation module contains a current mapping model; the input of the current mapping model is the actual driving current at the input end of the semiconductor laser, and the output is the preset test current value on which the control chassis generates the actual driving current. During aging and lifespan testing, the current compensation module collects the actual drive current at the input of the semiconductor laser in real time. Based on the actual drive current and the current mapping model, the current compensation module calculates the current compensation difference; the control chassis adjusts the drive current currently supplied to the input terminal of the semiconductor laser based on the current compensation difference to avoid circuit losses affecting the accuracy of the current supplied to the semiconductor laser.

2. The aging and lifespan assessment test system for aerospace semiconductor lasers according to claim 1, characterized in that: The control chassis includes a power supply unit, a control unit, a drive unit, and a temperature control unit; The power supply unit provides power to the control unit, drive unit, and temperature control unit; The control unit controls the drive unit to generate a corresponding drive current based on a preset test current value; the drive unit sends the generated drive current to the heat sink, and the heat sink transmits the drive current to the input end of the semiconductor laser, driving the semiconductor laser to start working. The temperature control unit provides excitation current to the cooler of the semiconductor laser and simultaneously collects the internal temperature of the semiconductor laser in real time, transmitting the collected temperature to the control unit. The control unit compares the collected temperature with the preset test temperature and adjusts the excitation current provided by the temperature control unit to the cooler based on the temperature comparison result, thereby achieving temperature compensation of the semiconductor laser and keeping the temperature of the semiconductor laser at the preset test temperature.

3. The aging and lifespan assessment test system for aerospace semiconductor lasers according to claim 2, characterized in that: The control unit adjusts the excitation current provided by the temperature control unit to the cooler based on the temperature comparison results. Specifically, when the collected temperature is lower than the preset test temperature, the control unit controls the temperature control unit to provide a reverse excitation current to the cooler, so that the cooler is in a heating state to increase the internal temperature of the semiconductor laser. The magnitude of the provided reverse excitation current is calculated by the control unit based on the temperature comparison results using a PID algorithm. When the collected temperature is higher than the preset test temperature, the control unit controls the temperature control unit to provide a positive excitation current to the cooler, so that the cooler is in a cooling state to reduce the internal temperature of the semiconductor laser; the magnitude of the provided positive excitation current is calculated by the control unit based on the temperature comparison results through a PID algorithm.

4. The aging and lifespan assessment test system for aerospace semiconductor lasers according to claim 2, characterized in that: The test system also includes a PC; the PC is connected to the control unit in the control chassis via a gigabit Ethernet port. The tester inputs the preset test current value and preset test temperature into the PC. After input, the PC transmits the preset test current value and preset test temperature to the control unit. At the same time, the control unit transmits the temperature collected by the temperature control unit to the PC. The PC displays the temperature collected by the temperature control unit for the tester to view.

5. The aging and lifespan assessment test system for aerospace semiconductor lasers according to claim 2, characterized in that: The driving unit includes an MCU, a driving analog-to-digital converter, a driving operational amplifier, a driving digital-to-analog converter, and a laser driving circuit; The power supply unit provides analog current to the drive unit; the drive analog-to-digital converter converts the analog current provided by the power supply unit into drive digital current; the drive digital current enters the drive operational amplifier, which amplifies the drive digital current to obtain the drive amplified digital current; the control unit sends a control signal corresponding to the preset drive current value to the MCU based on the preset drive current value; after receiving the control signal, the MCU adjusts the drive amplified digital current to the drive digital current corresponding to the preset drive current value. The driving digital current enters the driving digital-to-analog converter and is converted into driving analog current; the laser driving circuit finally converts the driving analog current into driving current and delivers it to the heat sink. The temperature control unit includes an MCU, a temperature control analog-to-digital converter, a temperature control operational amplifier, a temperature control digital-to-analog converter, and a laser temperature control circuit; The power supply unit provides analog current to the temperature control unit; the temperature control analog-to-digital converter converts the analog current provided by the power supply unit into a temperature control digital current; the temperature control digital current enters the temperature control operational amplifier, which amplifies the temperature control digital current to obtain a temperature control amplified digital current; based on the temperature comparison result, the control unit sends the control signal corresponding to the temperature comparison result to the MCU; after receiving the control signal, the MCU adjusts the temperature control amplified digital current to the temperature control drive digital current corresponding to the temperature comparison result; the temperature control drive digital current enters the temperature control digital-to-analog converter and is converted into a temperature control analog current; finally, the laser temperature control circuit converts the temperature control analog current into an excitation current and supplies it to the cooler of the semiconductor laser.

6. The aging and lifespan assessment test system for aerospace semiconductor lasers according to claim 1, characterized in that: The current compensation module includes a current acquisition circuit and a current compensation calculation unit; The current acquisition circuit acquires the actual driving current at the input end of the semiconductor laser in real time and transmits the acquired actual driving current to the current compensation calculation unit. The current compensation calculation unit contains a current mapping model. The current compensation calculation unit calculates the current compensation difference based on the current mapping model and the actual drive current. The steps for constructing the current mapping model are as follows: The first step is to instruct the control chassis to generate drive currents according to multiple preset test current values. Each drive current is transferred to the input end of the semiconductor laser through a heat sink. The second step is to measure the actual drive current at the input of the semiconductor laser under each drive current. The third step is to fit the relationship expression between the actual driving current and the preset test current value using the Newton interpolation polynomial fitting method, thereby obtaining the current mapping model.

7. The aging and lifespan assessment test system for aerospace semiconductor lasers according to claim 6, characterized in that: The specific process by which the current compensation calculation unit calculates the current compensation difference is as follows: The first step is for the current compensation module to input the actual driving current of the semiconductor laser into the current mapping model to obtain the preset test current value corresponding to the actual driving current. The second step is to calculate the initial current compensation difference I, using the following formula: I = |I1 - I2| / 2 Where I1 is the actual driving current and I2 is the preset test current value output by the current mapping model; The third step is to determine whether the initial current compensation difference is greater than the preset difference threshold. If the current compensation difference is greater than the preset difference threshold, the initial current compensation difference is used as the final current compensation difference; otherwise, the final current compensation difference is set to 0. The control chassis adjusts the driving current supplied to the semiconductor laser input based on the current compensation difference as follows: When the actual driving current I1 is less than the preset test current value I2 output by the current mapping model, the adjusted driving current I3 generated by the control chassis is: I3=I'+I When the actual drive current I1 is greater than the preset test current value I2 output by the current mapping model, the adjusted drive current I3 generated by the control chassis is: I3=I'-I Where I' is the drive current currently supplied by the control chassis to the input terminal of the semiconductor laser.

8. The aging and lifespan assessment test system for aerospace semiconductor lasers according to claim 1, characterized in that: The heat sink includes a heat sink plate and a clamp; the clamp is used to fix the semiconductor laser on the heat sink plate; the heat sink plate is used to homogenize local hot spots of the semiconductor laser and dissipate heat; the clamp is connected to the control chassis via a cable; the clamp is provided with pins for connecting to pins on the semiconductor laser.

9. The aging and lifespan assessment test system for aerospace semiconductor lasers according to claim 1, characterized in that: When the semiconductor laser is an N-type semiconductor laser, the pin connection between the heat sink and the semiconductor laser adopts an N-type connection method, specifically: The anode of the cooler on the heat sink is connected to the anode of the cooler of the N-type semiconductor laser; the first thermistor electrode on the heat sink is connected to the first thermistor electrode of the N-type semiconductor laser; the anode of the detector on the heat sink is connected to the anode of the detector of the N-type semiconductor laser; the cathode of the detector on the heat sink is connected to the cathode of the detector of the N-type semiconductor laser; the second thermistor electrode on the heat sink is connected to the second thermistor electrode of the N-type semiconductor laser; the anode of the laser diode chip on the heat sink is connected to the anode of the laser diode chip of the N-type semiconductor laser; the cathode of the laser diode chip on the heat sink is connected to the cathode of the laser diode of the N-type semiconductor laser; the cathode of the cooler on the heat sink is connected to the cathode of the cooler of the N-type semiconductor laser; the first, second, third, fourth, fifth, and sixth unused pins on the heat sink are respectively connected to the first, second, third, fourth, fifth, and sixth unused pins of the N-type semiconductor laser. When the semiconductor laser is an S-type semiconductor laser, the heat sink and the pins of the semiconductor laser are connected in an S-type configuration, specifically as follows: The anode of the cooler on the heat sink is connected to the anode of the cooler of the S-type semiconductor laser; the first thermistor electrode on the heat sink is connected to the first thermistor electrode of the S-type semiconductor laser; the anode of the detector on the heat sink is connected to the anode of the detector of the S-type semiconductor laser; the cathode of the detector on the heat sink is connected to the cathode of the detector of the S-type semiconductor laser; the second thermistor electrode on the heat sink is connected to the second thermistor electrode of the S-type semiconductor laser; the anode of the laser diode chip on the heat sink is connected to the anode of the laser diode chip of the S-type semiconductor laser; the cathode of the laser diode chip on the heat sink is connected to the cathode of the laser diode chip of the S-type semiconductor laser; the cathode of the semiconductor cooler on the heat sink is connected to the cathode of the cooler of the S-type semiconductor laser; the first, second, third, fifth, and sixth unused pins on the heat sink are respectively connected to the first, second, third, fourth, and fifth unused pins of the S-type semiconductor laser.

10. A method for aging and lifespan assessment of aerospace semiconductor lasers, characterized in that: The test method is based on the aging and lifespan assessment test system for aerospace semiconductor lasers as described in any one of claims 1 to 9. The specific steps are as follows: (1) Place the semiconductor laser inside the temperature chamber; the heat sink is connected to the semiconductor laser through pins, and the control chassis is connected to the heat sink through cables; (2) Start the control box; the control box generates a drive current based on the preset test current value; The driving current is transferred to the input terminal of the semiconductor laser through the heat sink to drive the semiconductor laser to work; (3) Activate the heat sink to homogenize the local hot spots of the semiconductor laser and dissipate heat; (4) Start the current compensation module, collect the driving current at the input end of the semiconductor laser in real time, and perform curve fitting on all the collected driving currents at preset intervals to obtain the driving current fitting result; The current compensation module calculates the current compensation difference based on the driving current fitting result and the preset test current value; the control chassis adjusts the driving current currently supplied to the input terminal of the semiconductor laser based on the current compensation difference to avoid circuit loss affecting the accuracy of the current supplied to the semiconductor laser. (5) Start the incubator and slowly raise the temperature of the incubator from low to high; During the temperature control process, the internal temperature of the semiconductor laser is monitored in real time. When the internal temperature of the semiconductor laser reaches the preset test temperature, the temperature control of the temperature chamber is stopped. (6) Maintain the temperature of the incubator to the preset test time; Throughout the process, the control unit performs real-time temperature compensation for the semiconductor laser, ensuring that the internal temperature of the semiconductor laser remains at the preset test temperature. (7) After the preset test time is reached, close the temperature chamber, control box and heat sink, and remove the semiconductor laser from the temperature chamber; (8) Test whether the semiconductor laser can work properly; If the semiconductor laser can function normally, then the semiconductor laser has passed the aging and lifespan test. Otherwise, the semiconductor laser failed the aging and lifespan test.

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