Temperature rise measuring method, device and equipment of grating and storage medium

Abstract

The invention discloses a grating temperature rise measuring method, device and equipment and a storage medium, and belongs to the technical field of lasers. The temperature rise measurement method is used for temperature rise measurement of a grating integrated in a laser system, and comprises the following steps: acquiring a laser output wavelength of the laser system; and determining the temperature rise of the grating according to the obtained laser output wavelength and the calibrated temperature drift coefficient of the grating. Because the diffraction wavelength of the grating linearly drifts along with the temperature, the method can directly reflect the steady-state and dynamic temperature conditions of the grating in a laser system, thereby avoiding the interference problem possibly brought by a traditional temperature detector, improving the accuracy and reliability of a measurement result, and improving the accuracy and reliability of the measurement result. And an efficient and accurate solution is provided for in-situ evaluation of a compact laser system and a packaging device. In addition, according to the method, a laser system structure does not need to be disassembled or changed, an external sensor does not need to be introduced, the test process is greatly simplified, the measurement error is reduced, and the operation difficulty is reduced.

Description

Technical Field

[0001] This invention relates to the field of laser technology, and in particular to a method, apparatus, device, and storage medium for measuring the temperature rise of a grating. Background Technology

[0002] Gratings (such as volume Bragg gratings, VBGs) are key optical components in laser systems, possessing high wavelength selectivity and stability, and are widely used in applications such as spectral beam combining, wave locking, and frequency stabilization. As lasers evolve towards higher power, miniaturization, and integration, the temperature rise effect caused by the absorption of laser energy during operation becomes increasingly prominent. This temperature rise leads to diffraction wavelength drift, decreased diffraction efficiency, and even thermally induced deformation, directly affecting the laser's output spectrum and long-term stability. Therefore, developing efficient and accurate methods for testing grating temperature rise is crucial for evaluating the reliability of gratings in laser systems.

[0003] Currently, temperature rise testing of optical components mainly relies on direct temperature measurement technology. For example, patent CN116698366A discloses a temperature rise testing device for optical components, which includes a laser generator, a collimation assembly, a temperature detector (such as an infrared thermal imager), and a power meter. This device simulates the laser irradiation environment inside a pump tube using a laser generator, and simultaneously measures the temperature rise of the optical component per unit time using a temperature detector (such as an infrared thermal imager) and a power meter. While this device improves detection efficiency, it relies on contact or near-field temperature measurement methods such as infrared thermal imagers, which have inherent limitations: infrared thermal imagers can only measure the surface temperature of optical components and are easily affected by the high reflectivity of gratings and mirror coatings, leading to problems such as false hot spots, large deviations, and poor repeatability in the measurement results. In addition, the core of this device is offline testing by physically placing the optical component, which is difficult to apply to highly integrated laser systems or in-situ testing scenarios.

[0004] Patent CN118706408 A further proposes a comprehensive testing device for the thermal effects of optical components under continuous laser irradiation. This device integrates functions such as temperature rise testing, wavefront phase testing, and beam quality testing, and can achieve automated measurement through computer control. The system in this patent can acquire temperature rise data with time-resolved characteristics (e.g., by fitting temperature rise curves using polynomials) and explore the correlation between thermal effects and wavefront distortion and beam quality. However, its temperature testing section still relies on an infrared thermal imager, making it difficult to overcome the physical limitations of surface measurement. Furthermore, the testing process requires the optical components to be exposed to the external environment, making it unsuitable for packaged devices or compact laser systems.

[0005] The aforementioned existing technologies demonstrate that traditional temperature rise testing methods suffer from the following common problems: (1) Limitations of surface measurement: Direct temperature measurement techniques such as infrared thermal imager can only obtain the surface temperature of optical components, and it is difficult to reflect the internal heat distribution. Especially for components with complex internal structures or coatings, such as gratings, the measurement results are easily affected by reflection and emissivity. (2) Intrusive testing: The devices involved in patent CN116698366 A and patent CN118706408 A require placing optical components in a dedicated testing station and disassembling or modifying the laser system structure. Therefore, they are not suitable for highly integrated lasers in industrial applications and cannot meet the requirements of in-situ testing. (3) Complexity and error: Although the system of patent CN118706408 A is fully functional, the optical path structure is complicated (involving multiple components such as beam splitter and filter), which not only increases the system error, but also increases the difficulty of operation, and cannot solve the problem of temperature measurement deviation caused by the high reflectivity of the grating. Therefore, existing technologies still need to be improved and developed. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the purpose of this invention is to provide a method, apparatus, device and storage medium for measuring the temperature rise of a grating, which aims to solve the problems of surface measurement limitations, invasive testing and complexity and error in traditional temperature rise testing methods.

[0007] The technical solution of the present invention is as follows: A first aspect of the present invention provides a method for measuring the temperature rise of a grating, wherein the method is used for measuring the temperature rise of a grating integrated into a laser system, the temperature rise measurement method comprising the steps of: Obtain the laser output wavelength of the laser system; The temperature rise of the grating is determined based on the obtained laser output wavelength and the calibrated temperature drift coefficient of the grating.

[0008] Optionally, when the grating is not integrated into the laser system, a TEC (thermal refrigeration) temperature controller is used to control the temperature of the grating, and the temperature drift coefficient of the grating is calibrated through a closed-loop temperature control system.

[0009] Optionally, the temperature drift coefficient of the grating has the following relationship: Δλ = k·ΔT, where k is the temperature drift coefficient of the grating, in nm / °C, Δλ is the change in laser output wavelength, and ΔT is the temperature rise of the grating.

[0010] Optionally, a spectral analysis instrument can be used to obtain the laser output wavelength of the laser system.

[0011] Optionally, the laser output wavelength of the laser system is acquired in real time, and the temperature rise of the grating is determined in real time based on the acquired laser output wavelength and the calibrated temperature drift coefficient of the grating.

[0012] A second aspect of the present invention provides a temperature rise measuring device for a grating, wherein the device is used for measuring the temperature rise of a grating integrated into a laser system, the temperature rise measuring device comprising: The acquisition module is used to acquire the laser output wavelength of the laser system; The determination module is used to determine the temperature rise of the grating based on the acquired laser output wavelength and the calibrated temperature drift coefficient of the grating.

[0013] A third aspect of the present invention provides a temperature rise measurement device for a grating, comprising a memory, a processor, and a temperature rise measurement program for the grating stored in the memory and executable on the processor, the temperature rise measurement program for the grating being configured to implement the steps of the temperature rise measurement method for the grating as described in the present invention.

[0014] A fourth aspect of the present invention provides a storage medium storing a temperature rise measurement program for a grating, wherein the temperature rise measurement program for the grating, when executed by a processor, implements the steps of the temperature rise measurement method for the grating as described in the present invention.

[0015] Beneficial Effects: This invention provides a grating temperature rise testing method based on wavelength drift. This method utilizes the physical property that the diffraction wavelength of a grating drifts linearly with temperature (i.e., temperature drift characteristic), and indirectly calculates the temperature change (i.e., temperature rise) of the grating by monitoring changes in the laser output wavelength. Since the diffraction wavelength of the grating drifts linearly with temperature, this method can directly reflect the steady-state and dynamic temperature status of the grating in the laser system structure. This not only avoids interference problems that may arise from traditional temperature detectors (such as infrared thermal imagers), but also significantly improves the accuracy and reliability of the measurement results, providing an efficient and accurate solution for in-situ temperature rise assessment of compact laser systems and packaged devices. Furthermore, this method not only achieves non-invasive temperature rise measurement, requiring neither disassembly nor modification of the laser system structure nor the introduction of external sensors, but also greatly simplifies the testing process, reduces measurement errors, and lowers operational difficulty. Attached Figure Description

[0016] Figure 1 This is a schematic flowchart of a method for measuring the temperature rise of a grating provided by the present invention.

[0017] Figure 2 This is a schematic diagram of a temperature rise measurement device for a grating provided by the present invention. Detailed Implementation

[0018] This invention provides a method, apparatus, device, and storage medium for measuring the temperature rise of a grating. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0019] As lasers evolve towards higher power, miniaturization, and integration, the temperature rise effect caused by gratings absorbing laser energy during operation becomes increasingly prominent. This temperature rise leads to diffraction wavelength drift, decreased diffraction efficiency, and even thermally induced deformation, directly impacting the laser's output spectrum and long-term stability. Therefore, developing efficient and accurate methods for testing grating temperature rise is crucial for evaluating the reliability of gratings in laser systems.

[0020] Based on this, the present invention provides a method for measuring the temperature rise of a grating, used for measuring the temperature rise of a grating integrated into a laser system, such as... Figure 1 As shown, the temperature rise measurement method includes the following steps: S100: Obtain the laser output wavelength of the laser system; S200. Based on the obtained laser output wavelength and the calibrated temperature drift coefficient of the grating, the temperature rise of the grating is determined.

[0021] This invention provides a grating temperature rise testing method for evaluating the temperature rise of gratings integrated into laser systems. Employing a wavelength drift method, this method only requires monitoring the laser output wavelength to calculate the grating's temperature rise, eliminating the need for disassembly or structural alterations. This is particularly suitable for in-situ testing of highly integrated laser systems or packaged devices. Since the diffraction wavelength of the grating drifts linearly with temperature, this method directly reflects the steady-state and dynamic temperature status of the grating within the laser system structure. This not only avoids interference issues that may arise from traditional temperature sensors (such as infrared thermal imagers) but also significantly improves measurement accuracy and response speed. In practical applications, the grating's temperature information can be obtained in real time simply by monitoring changes in the laser output wavelength using a spectral analysis instrument (such as a spectrometer, wavelength meter, or monochromator), providing strong support for the stable operation and performance optimization of the laser system.

[0022] The working principle of this invention is as follows: Based on the temperature drift characteristics of the grating: its diffraction wavelength (λ) drifts linearly with temperature (T), with the relationship Δλ = k·ΔT, where k is the temperature drift coefficient (unit: nm / °C). Under steady-state and dynamic conditions, this invention can track the temperature rise of the grating in real time based on the laser output wavelength obtained in real time, with an accuracy of ±0.1°C (the specific accuracy depends on the calibration accuracy of the k value).

[0023] In contrast, infrared thermal imagers are susceptible to environmental reflections, and their deviations typically exceed ±1°C. For example, in high-power lasers, this invention can detect extremely small wavelength shifts (such as 0.01 nm), which correspond to a temperature rise of 0.1°C, thus providing a direct warning of the risk of thermal failure.

[0024] In practical applications, a TEC (Thermal Design Temperature) system is first used to control the temperature of the grating. Simultaneously, a closed-loop temperature control system is used to precisely calibrate the grating's temperature drift coefficient k, which is a key parameter for accurate subsequent temperature rise calculations. During laser system operation, a high-precision wavelength measurement device is used to acquire the laser output wavelength in real time. Combined with the calibrated temperature drift coefficient k and the aforementioned relationship, the real-time temperature rise of the grating can be calculated quickly and accurately. This measurement method is unaffected by the complex structure of the laser system and can operate stably and reliably in both simple experimental environments and complex industrial applications, providing strong data support for laser system performance monitoring and fault diagnosis.

[0025] To achieve closed-loop temperature control of the grating by the TEC temperature controller and calibrate the temperature drift characteristics of the diffraction wavelength, the key lies in constructing a cyclic system of "target setting—actual measurement—deviation calculation—adjustment execution—deviation correction," which precisely controls the temperature and synchronously records changes in temperature and wavelength. The following modules work together: 1. Grating controlled by the TEC: The grating is in close contact with the TEC, avoiding interference from the external environment; 2. TEC semiconductor cooling chip: It achieves cooling or heating by switching the current direction. Its hot side needs to be fitted with a heat sink or fan for forced heat dissipation to avoid heat buildup affecting efficiency; 3. Temperature sensor (such as a miniature thermocouple): It is tightly attached to the grating using thermally conductive adhesive for real-time feedback of the actual temperature; 4. Temperature controller is a PID module (or a microcontroller + PID code): As the "brain," it receives the deviation between the set temperature and the measured temperature, calculates the control signal using a proportional-integral-derivative algorithm, and drives the TEC to adjust the current to correct the temperature. Closed-loop temperature control achieves precise control of the grating temperature through a cyclic process of "thermocouple temperature measurement - PID deviation calculation - TEC heat adjustment". The temperature drift characteristics can be calibrated by recording data synchronously.

[0026] In other words, the temperature rise measurement method of this invention is mainly as follows: 1. A TEC (thermoelectric cooling) temperature controller is used to control the temperature of the grating. A closed-loop temperature control system (feedback of the grating temperature to the system via thermocouples, combined with a PID (proportional-integral-derivative) controller) is used to calibrate the relationship between its diffraction wavelength and temperature, i.e., its temperature drift characteristics. 2. When the grating is integrated into a laser system, the laser output wavelength of the laser system is measured. 3. Based on the measured laser output wavelength and the temperature drift characteristics of the grating, the temperature change of the grating (i.e., temperature rise) can be calculated.

[0027] Traditional infrared thermometry methods are highly susceptible to the low emissivity and high reflectivity of gratings, especially in the presence of specular coatings or transparent materials. Infrared imaging often suffers from false hotspots, significant deviations, and poor repeatability. However, the wavelength-drift indirect method of this invention directly reflects the functional state of the grating, with its diffraction wavelength shifting linearly with temperature. This indicator is not only unaffected by surface interference but also possesses a clear physical directionality, directly correlated with the laser's spectral performance and wave-locking stability. This wavelength-drift indirect method effectively overcomes the physical limitations of measuring only surface temperature and being susceptible to reflection interference.

[0028] Specifically, the temperature rise measurement method of the present invention has the following technical advantages: 1. Practical advantages (1) Close to actual working conditions: The wavelength change truly reflects the spectral stability of VBG and is directly related to the actual wave-locking effect; it is not just a physical value of temperature, but the actual impact of temperature on performance. (2) Adaptable to various laser structures: It can operate on lasers with different packages and different powers; no need to modify or disassemble the internal structure, especially suitable for high-integration packaged lasers with small size and limited internal space. (3) Suitable for dynamic testing: It can be used for temperature rise tracking during power-on instant, thermal steady-state process and power step change.

[0029] 2. Convenience Advantage (1) No contact or disassembly required: No need to attach thermocouples to the VBG, change the structure, or reinstall the laser; it is especially convenient for testing existing products or finished products and can be applied to quality control on the production line or customer side. (2) Easy to integrate with automated measurement and control system: It can be connected to the spectral monitoring module to realize temperature-wavelength closed-loop control; it is easy to realize online adjustment or compensation mechanism, and is suitable for high-end laser system design.

[0030] The present invention also provides a temperature rise measuring device for a grating, used for measuring the temperature rise of a grating integrated into a laser system, such as... Figure 2 As shown, the temperature rise measuring device includes: Acquisition module 100 is used to acquire the laser output wavelength of the laser system; The determination module 200 is used to determine the temperature rise of the grating based on the acquired laser output wavelength and the calibrated temperature drift coefficient of the grating.

[0031] The present invention also provides a temperature rise measurement device for a grating, comprising a memory, a processor, and a temperature rise measurement program for the grating stored in the memory and executable on the processor, the temperature rise measurement program for the grating being configured to implement the steps of the temperature rise measurement method for the grating as described in the present invention.

[0032] The present invention also provides a storage medium, wherein the storage medium stores a temperature rise measurement program for a grating, and when the temperature rise measurement program for the grating is executed by a processor, it implements the steps of the temperature rise measurement method for the grating as described in the present invention.

[0033] In summary, this invention provides a method, apparatus, device, and storage medium for measuring the temperature rise of a grating. The method, used for measuring the temperature rise of a grating integrated into a laser system, includes the steps of: acquiring the laser output wavelength of the laser system; and determining the temperature rise of the grating based on the acquired laser output wavelength and the calibrated temperature drift coefficient of the grating. This method utilizes the physical characteristic that the diffraction wavelength of the grating drifts linearly with temperature (i.e., temperature drift characteristic) to indirectly calculate the temperature change (i.e., temperature rise) of the grating by monitoring changes in the laser output wavelength. Because the diffraction wavelength of the grating drifts linearly with temperature, this method can directly reflect the steady-state and dynamic temperature status of the grating in the laser system structure. It not only avoids the interference problems that may arise from traditional temperature detectors (such as infrared thermal imagers) but also significantly improves the accuracy and reliability of the measurement results, providing an efficient and accurate solution for in-situ temperature rise assessment of compact laser systems and packaged devices. In addition, this method not only achieves non-invasive temperature rise measurement, which does not require disassembly or modification of the laser system structure or the introduction of external sensors, but also greatly simplifies the testing process, reduces measurement errors, and lowers the difficulty of operation.

[0034] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A method for measuring the temperature rise of a grating, characterized in that, The temperature rise measurement method for gratings integrated into laser systems includes the following steps: Obtain the laser output wavelength of the laser system; The temperature rise of the grating is determined based on the obtained laser output wavelength and the calibrated temperature drift coefficient of the grating.

2. The method for measuring the temperature rise of a grating according to claim 1, characterized in that, When the grating is not integrated into the laser system, a semiconductor cooling temperature controller is used to control the temperature of the grating. At the same time, the temperature drift coefficient of the grating is calibrated through a closed-loop temperature control system.

3. The method for measuring the temperature rise of a grating according to claim 1, characterized in that, The temperature drift coefficient of the grating has the following relationship: Δλ = k·ΔT, where k is the temperature drift coefficient of the grating, in nm / °C, Δλ is the change in laser output wavelength, and ΔT is the temperature rise of the grating.

4. The method for measuring the temperature rise of a grating according to claim 1, characterized in that, The laser output wavelength of the laser system was obtained using a spectral analysis instrument.

5. The method for measuring the temperature rise of a grating according to claim 1, characterized in that, The laser output wavelength of the laser system is acquired in real time, and the temperature rise of the grating is determined in real time based on the acquired laser output wavelength and the calibrated temperature drift coefficient of the grating.

6. A temperature rise measuring device for a grating, characterized in that, For measuring the temperature rise of a grating integrated into a laser system, the temperature rise measuring device includes: The acquisition module is used to acquire the laser output wavelength of the laser system; The determination module is used to determine the temperature rise of the grating based on the acquired laser output wavelength and the calibrated temperature drift coefficient of the grating.

7. A temperature rise measuring device for a grating, characterized in that, The device includes a memory, a processor, and a temperature rise measurement program for a grating stored in the memory and executable on the processor, the temperature rise measurement program for the grating being configured to implement the steps of the temperature rise measurement method for the grating as described in any one of claims 1-5.

8. A storage medium, characterized in that, The storage medium stores a temperature rise measurement program for the grating, which, when executed by a processor, implements the steps of the temperature rise measurement method for the grating as described in any one of claims 1-5.

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