Single-frequency laser service life characterization testing device and method

Abstract

The service life characterization testing device comprises a light beam splitter, a high-stability laser frequency reference module, power detection equipment, a wavelength testing module, line width / relative intensity noise / frequency noise testing equipment, a control computer and software, a driving / temperature control power supply and the like. The output light of the tested single-frequency laser is divided into multiple paths through a plurality of light beam splitters, and the output light power, the output wavelength, the absolute wavelength change and the relative intensity noise / frequency noise are monitored respectively. According to the absolute wavelength change monitoring, light needs to pass through a high-stability frequency reference module and then pass through a PD to monitor the change value of the absolute wavelength. According to the invention, a plurality of parameters are monitored in a multi-channel monitoring mode, and the system has the advantages of simple parameter testing, comprehensive monitoring of life characterization parameters and the like, and is suitable for performance testing and life testing of a single-frequency solid laser, a single-frequency fiber laser, a single-frequency semiconductor laser and the like.

Description

Technical Field

[0001] The invention relates to laser life test technology, in particular to a single-frequency laser life test device and a device. Background Art

[0002] Single-frequency lasers, including single-frequency semiconductor lasers, single-frequency solid-state lasers and single-frequency fiber lasers, have significant advantages such as narrow line width, good frequency stability and low noise, and have broad application potential in high-precision optical sensing, lidar, gravitational wave detection, ultracold atom experiments, coherent laser communications, etc. With the widespread application of single-frequency lasers, the service life of single-frequency lasers has become a core indicator for measuring their performance.

[0003] Traditionally, the evaluation of laser life mainly relies on the continuous monitoring of its output power, and the power change is used as the main basis for characterizing the decline of laser life. However, single-frequency lasers under long-term operation not only face the decline of output power, but also may encounter problems such as line width degradation, wavelength shift or noise increase. These problems may cause the laser to fail to meet the strict requirements of specific application scenarios even if the power can still meet the basic mission requirements, thereby affecting the performance and reliability of the terminal equipment.

[0004] Patent document CN105651489A monitors and evaluates the health status of key modules of the test system during the life test of high-power semiconductor lasers to avoid interruption of life test due to failure of the life test system. The parameter test modules involved include stepper motors and parameter test instruments, which focus on monitoring sensitive parameters such as the output power and center wavelength of the laser; Patent document CN102062675B discloses a multi-channel semiconductor laser life test device, which collects and stores the power information and spectral information of multiple identical lasers during operation by moving the integrating sphere and the power detection PD, providing a basis for long-term reliability research of lasers. Patent document CN102519709B proposes to monitor a batch of semiconductor lasers throughout the aging life test process, and monitor the power or light intensity of the tested laser in real time. Patent CN117031237B proposes a semiconductor device life test method and system, which mainly involves field effect tubes, tests the test temperature, drain voltage and drain current, and predicts the service life, but does not involve laser devices.

[0005] Although the above patents have made significant progress in the field of laser life testing, they mainly focus on monitoring power and spectral characteristics. In contrast, although patent CN117031237B proposes a life test method and system for semiconductor devices (especially field effect transistors), which predicts the life by testing parameters such as temperature, drain voltage and drain current, this solution is not directly applicable to laser devices, especially the special needs and performance evaluation of single-frequency lasers.

[0006] In summary, although there are currently a variety of laser life testing technologies, the comprehensive monitoring and evaluation scheme for problems such as line width degradation, wavelength deviation and noise increase that may occur in single-frequency lasers during long-term operation still needs to be further developed and improved. Summary of the invention

[0007] The present invention aims to overcome the limitation of incomplete monitoring parameters in the above-mentioned existing laser life test, and proposes a single-frequency laser life characterization test device and method. The device can not only continuously monitor the conventional output power and wavelength, but also expand the monitoring of key parameters such as absolute wavelength drift, line width, relative intensity noise and frequency noise, so as to more comprehensively evaluate the performance status of the single-frequency laser and accurately characterize its life.

[0008] The technical solution of the present invention is as follows:

[0009] A single-frequency laser lifetime characterization test device, characterized in that the device comprises an optical splitter, a high-stable laser frequency reference module, a power detection device, a wavelength test module, a line width / relative intensity noise / frequency noise test device, a control computer and software, and a drive / temperature control power supply; wherein the optical splitter is used to split the output light of the single-frequency laser to be tested into N paths, and N ≥ 2; the high-stable laser frequency reference module is connected to at least one optical path after the splitting, and is used to monitor the absolute wavelength change of the light, including an optical frequency multiplier and a gas absorption cell component; the power detection device is connected to at least one optical path after the splitting, and is used to monitor the output light power; the wavelength test module A block is connected to at least one optical path after splitting, and is used to monitor the output wavelength; a line width / relative intensity noise / frequency noise test device is connected to at least one optical path after splitting, and is used to monitor the relative intensity noise and / or frequency noise; a control computer and software are used to control the operation of the entire test device, including the temperature control of the single-frequency laser to be tested, the frequency doubling component and the gas absorption cell component by the driving / temperature control power supply, and the current scanning and temperature scanning of the single-frequency laser to be tested are performed by software control, and the test data are recorded; the driving / temperature control power supply is used to provide the required driving current and temperature control for the single-frequency laser to be tested, the frequency doubling component and the gas absorption cell component.

[0010] Preferably, the optical splitter can use a spatial optical element to split the light beam, or can use a 1*2 optical fiber splitter cascaded to split the light beam, and the number of splitting paths N≥2.

[0011] Preferably, the high-stable laser frequency reference module includes but is not limited to an optical frequency doubler and various gas absorption cell components, various absorption cell components, a high-precision FP cavity, etc. The laser enters the high-stable laser frequency reference module to monitor the absolute wavelength of the light.

[0012] Preferably, the device under test includes a single-frequency semiconductor laser, a single-frequency solid laser, a single-frequency fiber laser, etc., and the output mode of the device under test includes fiber-coupled output and spatial light output.

[0013] Preferably, the optical frequency doubler includes but is not limited to a periodically poled lithium niobate PPLN bulk frequency doubler, a periodically poled lithium niobate PPLN waveguide frequency doubler, a potassium titanyl phosphate KTP frequency doubler, and the like.

[0014] Preferably, the gas absorption cell assembly includes but is not limited to a rubidium Rb absorption cell assembly, a cesium Cs absorption cell assembly, an iodine absorption cell assembly, a potassium absorption cell assembly, and the like.

[0015] Preferably, the lifetime characterization device can simultaneously monitor performance indicators such as output power, wavelength, absolute wavelength change, line width / relative intensity noise / frequency noise, etc., to characterize lifetime characteristics.

[0016] Preferably, the lifetime characterization test, during the long-term lifetime monitoring process, includes wavelength test module testing, line width / relative intensity noise / frequency noise, and threshold characteristic testing, and tests key performance parameters and records data by performing current scanning, temperature scanning, etc. on the device under test at regular intervals under software control.

[0017] On the other hand, the present invention also provides a life test method for a single-frequency laser life characterization test device, comprising the following steps:

[0018] ①Fix the optical splitter on the same platform, and the splitting ratio can be adjusted as needed;

[0019] ② Fix the frequency doubling component and the gas absorption cell component on the same optical platform;

[0020] ③After splitting, the wavelength test module tests the optical path, line width / relative intensity noise / frequency noise test using optical fiber coupling input to the corresponding test equipment;

[0021] ④After the life test device is built, the temperature of the device under test, frequency doubling components, and gas absorption cell components are controlled by the control computer and software;

[0022] ⑤ Through the control computer and software, the current and temperature scanning control of the device under test is carried out, and multiple signals are monitored at the same time, the corresponding parameters are tested, and recorded;

[0023] ⑥ After fixing the current and temperature of the device under test, conduct long-term life testing, continuously monitor the output power, wavelength and other parameters for a certain period of time, and record them.

[0024] ⑦ Characterize the life of the device under test through long-term uninterrupted monitoring and current and temperature scanning control monitoring parameters.

[0025] Furthermore, the long-term life monitoring process also includes threshold characteristic testing, in which the key performance parameters are tested and the data is recorded by performing current scanning and temperature scanning on the device under test at certain intervals through software control.

[0026] Compared with the prior art, the present invention has the following advantages:

[0027] 1) It can simultaneously monitor performance indicators such as output power, wavelength, absolute wavelength change, line width, relative intensity noise and frequency noise to characterize the life characteristics of the single-frequency laser being tested.

[0028] 2) By using spectroscopic method, different lifetime characterization parameters of the same device can be monitored simultaneously to characterize the performance and lifetime of the laser from multiple angles.

[0029] 3) The light passes through a highly stable laser frequency reference module to monitor the change in absolute wavelength, and more accurately test the change in device wavelength over time.

[0030] 4) In addition to long-term monitoring of important parameters, the threshold characteristics, absolute wavelength, line width and noise can be tested at certain intervals through computer and software control, and short-term stability indicators of key laser parameters can be obtained to provide data for applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments or technical solutions of the present invention, the following is a brief introduction to the drawings required for use in the embodiments or technical descriptions. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other similar drawings can be obtained based on these drawings without creative work.

[0032] Figure 1 A schematic block diagram of a single-frequency laser lifetime characterization test device according to the present invention;

[0033] Figure 2 This is a schematic diagram of the structure of Embodiment 1 of the present invention;

[0034] Figure 3 This is a schematic diagram of the structure of Embodiment 2 of the present invention;

[0035] Figure 4 This is a schematic diagram of the structure of Embodiment 3 of the present invention; DETAILED DESCRIPTION

[0036] The present invention will be further described below in conjunction with embodiments and drawings, but the protection scope of the present invention shall not be limited thereto.

[0037] Please refer to Figure 1 , Figure 1 It is a schematic block diagram of the single-frequency laser lifetime characterization test device of the present invention, and the device module mainly includes an optical beam splitter 11, a power detection device 12, a wavelength test module 13, a line width / relative intensity noise / frequency noise test device 14, a signal detection PD 15, a high-stability laser frequency reference module 16, a control computer and software 17, a drive / temperature control power supply 18, and a single-frequency laser 19.

[0038] The laser beam of the single-frequency laser 19 is divided into four paths through the optical beam splitter 11, one of which passes through the power detection device 12 to monitor the output power, one passes through the wavelength test module 13 to monitor the wavelength of the laser, one passes through the line width / relative intensity noise / frequency noise test device 14 to test the line width and noise characteristics of the laser, and the last path passes through the high-stability laser frequency reference module 16 to absorb the light, and the signal detection PD15 monitors the size of the output signal, thereby obtaining the change in the absolute wavelength of the single-frequency laser. The drive / temperature control power supply is controlled and data is collected by the control computer and software 17, thereby controlling the output performance of the single-frequency laser 19, and the control computer and software 18 collects and stores the detection signals of the power detection device 12, the wavelength test module 13, the line width / relative intensity noise / frequency noise test device 14, and the signal detection PD15.

[0039] The optical beam splitter divides the light into four paths, one of which passes through the power detection device 12 to monitor the output power, one passes through the wavelength test module 13 to monitor the wavelength of the laser, one passes through the line width / relative intensity noise / frequency noise test device 14 to test the line width and noise characteristics of the laser, and the last path is absorbed by the high-stability laser frequency reference module 16, and the signal detection PD15 is used to monitor the size of the output signal, thereby obtaining the change in the absolute wavelength of the single-frequency laser. The drive / temperature control power supply is controlled and data is collected by the control computer and software 17, thereby controlling the output performance 19 of the single-frequency laser. The control computer and software 17 collects and stores the detection signals of the power detection device 12, the wavelength test module 13, the line width / relative intensity noise / frequency noise test device 14, and the signal detection PD15.

[0040] Figure 2Schematic diagram of Embodiment 1 of the present invention, a single-frequency laser lifetime characterization test device, including an optical beam splitter 21 composed of a semi-transparent and semi-reflective mirror 21-1, a semi-transparent and semi-reflective mirror 21-2, a semi-transparent and semi-reflective mirror 21-3, and a highly reflective mirror 21-4, a power detection device 22 composed of a focusing lens 22-1 and a power detection 22-2, a wavelength test module 23 composed of a focusing lens 23-1 and a fiber coupling component 23-2, a line width / relative intensity noise / frequency noise test device 24 composed of a focusing lens 24-1 and a fiber coupling component 24-2, a signal detection PD 25, a beam shaping lens 26-1 and a frequency multiplier 26-2, and a high-stability laser frequency reference module 26 composed of a beam shaping lens 26-3 and a gas absorption cell component 26-4, a control computer and software 27, a drive / temperature control power supply 28, a single-frequency laser 29 (collimated light output), etc.

[0041] The collimated laser beam of the single-frequency laser 29 is split by the semi-transparent and semi-reflective mirror 21-1, and one path of light passes through the beam shaping lens 26-1 to enter the frequency doubler 26-2 to double the frequency of the beam, and the doubled frequency beam passes through the beam shaping lens 26-3 to enter the gas absorption cell 26-4, and the output optical signal is converted into an electrical signal by the signal detection PD25 for data collection and recording; the reflected light path split by the semi-transparent and semi-reflective mirror 21-1 is split by the semi-transparent and semi-reflective mirror 21-2, and the reflected light passes through the line width / relative intensity noise / frequency noise test equipment 24 composed of the focusing lens 24-1 and the optical fiber coupling component 24-2 to test the line width / relative intensity noise / frequency noise, and the test signal is collected and recorded by the control computer and software 27 ; The transmitted light path split by the semi-transparent and semi-reflective mirror 21-2, reflected by the semi-transparent and semi-reflective mirror 21-3, enters the wavelength test module 203 through the focusing lens 23-1 and the optical fiber coupling component 23-2 for wavelength testing, and the tested wavelength signal is collected and recorded by the control computer and software 27; the reflected light split by the semi-transparent and semi-reflective mirror 21-3, reflected by the high-reflective mirror 21-4, enters the power detection device 22-2 through the focusing lens 22-1, and the tested power signal is collected and recorded by the control computer and software 27; the control computer and software 27 control and collect data on the drive / temperature control power supply, thereby controlling the output performance of the single-frequency laser 29, and collecting and storing data on related parameters.

[0042] Figure 3 This is a schematic diagram of Example 2 of the present invention, and the structure of this embodiment is basically the same as that of Example 1. The difference is that in Example 2, the single-frequency laser 39-1 is a fiber-coupled output, and the light beam needs to be collimated by a laser collimating lens 39-2, and the transmitted light of the semi-transparent and semi-reflective mirror 31-3 passes through a focusing lens 32-1 and enters a power detection device 32-2 for power monitoring.

[0043] Figure 4 This is a schematic diagram of Example 3 of the present invention, a single-frequency laser lifetime characterization test device, including an optical beam splitter 41 composed of an optical fiber splitter 41-1, an optical fiber splitter 41-2, and an optical fiber splitter 41-3, a power detection device 42, a wavelength test module 43, a line width / relative intensity noise / frequency noise test device 44, a signal detection PD45, a beam shaping lens 46-1 and a frequency doubler 46-2, and a high-stability laser frequency reference module 46 composed of a beam shaping lens 46-3 and a gas absorption cell 46-4, as well as a control computer and software 47, a drive / temperature control power supply 48, a single-frequency laser 49 (fiber coupled output), etc.

[0044] The output laser of the single-frequency laser 49 (fiber coupled output, such as 1064nm) is split by the fiber beam splitter 41-1, and then by the fiber beam splitter 41-2 and the fiber beam splitter 41-3, and the output laser is divided into 4 paths. The split light enters the fiber coupled power detection device 42, the wavelength test module 43, and the line width / relative intensity noise / frequency noise test device 44 respectively to test and monitor the power, wavelength, line width / relative intensity noise / frequency noise. Another path of light passes through the beam shaping lens 46-1 and enters the optical frequency multiplier 46-2. The output 532nm laser passes through the beam shaping lens 46-3 and enters the iodine absorption cell assembly 46-4, and the signal is tested by the signal detection PD45.

[0045] The control and collection process of this embodiment is the same as that of embodiment 1.

Claims

1. A single-frequency laser lifetime characterization test device, characterized in that: include: An optical splitter, used to split the output light of the single-frequency laser to be tested into N paths, where N ≥ 2; A high-stability laser frequency reference module, connected to at least one optical path after the light splitting, for monitoring the absolute wavelength change of the light, including an optical frequency doubler and a gas absorption cell assembly; A power detection device is connected to at least one optical path after the light splitting, and is used to monitor the output optical power; A wavelength test module is connected to at least one optical path after the light splitting, and is used to monitor the output wavelength; Line width / relative intensity noise / frequency noise test equipment, connected to at least one split optical path, for monitoring relative intensity noise and / or frequency noise; Control computer and software, used to control the operation of the entire test device, including the temperature control of the single-frequency laser to be tested, the frequency doubling component and the gas absorption cell component by the driving / temperature control power supply, and the current scanning and temperature scanning of the single-frequency laser to be tested by software control, and record the test data; The driving / temperature control power supply is used to provide the required driving current and temperature control for the single-frequency laser, frequency doubling component and gas absorption cell component to be tested.

2. The single-frequency laser lifetime characterization test device according to claim 1, characterized in that: The single-frequency laser to be tested includes a single-frequency semiconductor laser, a single-frequency solid laser or a single-frequency fiber laser, and the output mode of the laser to be tested can be fiber-coupled output or spatial light output.

3. The single-frequency laser lifetime characterization test device according to claim 1, characterized in that: The optical splitter is a spatial optical element or a cascade of 1*2 optical fiber splitters.

4. The single-frequency laser lifetime characterization test device according to claim 1, characterized in that: The optical frequency doubler is a periodically poled lithium niobate PPLN block frequency doubler, a periodically poled lithium niobate PPLN waveguide frequency doubler or a potassium titanyl phosphate KTP frequency doubler.

5. The single-frequency laser lifetime characterization test device according to claim 1, characterized in that: The gas absorption cell assembly is a rubidium Rb absorption cell assembly, a cesium Cs absorption cell assembly, an iodine absorption cell assembly or a potassium absorption cell assembly.

6. A single-frequency laser lifetime characterization test method, characterized in that the steps include: Fix the optical splitter on the platform and adjust the splitting ratio as needed; Fix the frequency doubling assembly and the gas absorption cell assembly on an optical platform; The split optical paths are respectively connected to the wavelength test module, the line width / relative intensity noise / frequency noise test equipment and the power detection equipment; Temperature control of the device under test, frequency doubling components and gas absorption cell components is performed through the control computer and software; Through the control computer and software, the current and temperature of the device under test are scanned, and the parameters corresponding to multiple signals are monitored and recorded at the same time; After fixing the current and temperature of the single-frequency laser to be tested, a long-term life test is performed to continuously monitor and record the output power, wavelength and other parameters; The lifetime of the single-frequency laser to be tested is characterized by parameter data obtained through long-term uninterrupted monitoring and current and temperature scanning.

7. The single-frequency laser lifetime characterization test method according to claim 5, characterized in that: The long-term life monitoring process also includes threshold characteristic testing, which uses software control to perform current scanning and temperature scanning on the device under test at certain intervals to test key performance parameters and record data.

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