A real-time temperature monitoring method and monitoring system for a light source component

Abstract

A real-time temperature monitoring method for a light source assembly detects the light source assembly to obtain the corresponding relationship between the semiconductor laser's drive current I and the temperature T at the beam combining end. Based on the corresponding relationship between the semiconductor laser's drive current I and the temperature T at the beam combining end, a corresponding standard constant temperature is obtained according to a set semiconductor laser drive current. A temperature threshold is set based on the standard constant temperature. The real-time beam combining end temperature of the light source assembly is obtained and compared with the temperature threshold to determine whether the beam combining end temperature is abnormal. This allows for more accurate determination of beam combining end temperature abnormalities, preventing damage to the light source assembly due to overheating caused by abnormalities.

Description

Technical Field

[0001] The present invention relates to a light source assembly, and in particular to a real-time monitoring method and a monitoring system for the light source assembly. Background Art

[0002] Semiconductor lasers are commonly used laser light sources. They offer numerous advantages, including small size, light weight, low power consumption, and high efficiency. They are widely used in laser ranging, laser communications, and direct-write exposure. In direct-write exposure, multiple semiconductor lasers are typically combined as a single light source, using optical fibers for light transmission. The corresponding optical fibers for the semiconductor lasers are then combined for output.

[0003] During application, if some components in the light source assembly malfunction, it is very easy to cause the temperature of the fiber bundle end to rise rapidly, which will cause the optical fiber or optical components to burn, affecting the use of the light source assembly. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a real-time temperature monitoring method and monitoring system for a light source assembly, so as to prevent the light source assembly from being damaged due to overheating.

[0005] In order to solve the above problems, the present invention provides a real-time temperature monitoring method for a light source assembly. By detecting the light source assembly, the corresponding relationship between the driving current I of the semiconductor laser and the temperature T of the beam combining end is obtained; based on the corresponding relationship between the driving current I of the semiconductor laser and the temperature T of the beam combining end, the corresponding standard constant temperature is obtained according to the set driving current of the semiconductor laser; a temperature threshold is set according to the standard constant temperature; the real-time beam combining end temperature of the light source assembly is obtained, and compared with the temperature threshold to determine whether the beam combining end temperature is abnormal.

[0006] Furthermore, a method for detecting the semiconductor laser correspondence between the driving current I and the temperature T at the beam combining end is to set the driving currents of n different semiconductor lasers and obtain the optical power P of the beam combining head and the temperature T at the beam combining end corresponding to each driving current.

[0007] Furthermore, based on the optical output power P of the combining head and the temperature T of the combining end corresponding to the n groups of driving currents I, the relationship between the optical output power P of the combining head and the temperature T of the combining end, the relationship between the optical output power P and the driving current I, and the relationship between the temperature T of the combining end and the driving current I are obtained.

[0008] Furthermore, the relationship between the optical output power P of the beam combining head and the corresponding temperature T of the beam combining end is T= kx LnP+b, where k and b are constants; the relationship between the driving current I and the corresponding optical output power P of the beam combining head is P=mI+a, where m and a are constants; the relationship between the temperature T of the beam combining end and the driving current I of the semiconductor laser is T= kx Ln(mI+a)+ b.

[0009] Furthermore, the temperature threshold includes a standard constant temperature and a temperature variation that the optical fiber can withstand.

[0010] Furthermore, when judging whether the temperature of the beam combining end is abnormal, the collected real-time beam combining end temperature is compared with the standard constant temperature to judge whether the real-time beam combining end temperature is greater than the standard constant temperature. When the real-time beam combining end temperature is greater than the standard constant temperature, it is further judged whether the difference between the real-time beam combining end temperature and the standard constant temperature is greater than the temperature variation that the optical fiber can withstand. If the difference between the real-time beam combining end temperature and the standard constant temperature is greater than the temperature variation that the optical fiber can withstand, it is judged that an abnormality has occurred, and the abnormal information is fed back to the overall control system.

[0011] Furthermore, when determining whether the temperature at the beam combining end is abnormal, the real-time temperature at the beam combining end is compared with the temperature threshold of the beam combining end. When the real-time temperature at the beam combining end is greater than the temperature threshold of the beam combining end, it is determined that an abnormality has occurred, and the abnormality information is fed back to the overall control system. The beam combining end threshold is the sum of the standard constant temperature and the temperature variation that the optical fiber can withstand.

[0012] Furthermore, the inlet and outlet water temperatures of the light source assembly cooling part are collected in real time and compared with the set corresponding inlet or outlet water temperature thresholds. If the temperature is greater than the corresponding inlet or outlet water temperature threshold, an abnormal signal is output to the overall control system.

[0013] A real-time monitoring system using the above-mentioned method for real-time temperature monitoring of a light source assembly comprises a semiconductor laser, a laser driving board, a coupling module, an optical fiber, an optical fiber beam combiner, a cooling element, and a housing. The laser driving board controls the semiconductor laser to emit laser light. The coupling module connects the semiconductor laser and the optical fiber. The semiconductor laser and the coupling module are placed on the cooling element. The housing has an optical fiber outlet. The optical fiber is led out from the optical fiber outlet and beam-combined by the optical fiber beam combiner. The real-time monitoring system of the light source assembly comprises a beam combining temperature control module and a beam combining temperature probe. A beam combining temperature probe is provided at the beam combining head, and the beam combining temperature probe is connected to the beam combining temperature control module. The beam combining temperature control module includes a beam combining end temperature acquisition unit, a beam combining end constant temperature setting unit and a beam combining end temperature abnormality judgment unit. The beam combining end temperature acquisition unit obtains information from the beam combining temperature probe; the beam combining end constant temperature setting unit is used to obtain a corresponding standard constant temperature according to a set driving current of the semiconductor laser; the beam combining end temperature abnormality judgment unit is used to judge whether the real-time beam combining end temperature obtained by the beam combining end temperature acquisition unit from the beam combining temperature probe exceeds a temperature threshold set according to the standard constant temperature.

[0014] Furthermore, the beam combining temperature probe is arranged inside or on the side of the beam combining head.

[0015] Furthermore, the real-time monitoring system of the light source assembly also includes a water-cooled temperature control module, an outlet water temperature probe and an inlet water temperature probe. The outlet water temperature probe and the inlet water temperature probe are connected to the water-cooled temperature control module. The outlet water temperature probe and the inlet water temperature probe are used to collect the real-time temperature of the outlet water end and the inlet water end of the water-cooled component. The water-cooled temperature control module is used to determine whether the real-time temperature obtained by the outlet water temperature probe and the inlet water temperature probe exceeds the set corresponding outlet water temperature threshold or inlet water temperature threshold.

[0016] Compared with the existing technology, the real-time monitoring method of the light source component is based on the correspondence between the driving current I of the semiconductor laser and the temperature T of the beam combining end. According to the set driving current of the semiconductor laser, the corresponding standard constant temperature is obtained; the temperature threshold is set according to the standard constant temperature to judge whether the temperature of the beam combining end is abnormal, and the abnormal temperature of the beam combining end is judged more accurately to avoid damage to the light source component due to overheating caused by abnormality. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the light source component structure.

[0018] Figure 2 is a graph of example inspection data for a light source component.

[0019] Figure 3This is a schematic block diagram of the water cooling temperature control module.

[0020] Figure 4 This is a schematic block diagram of the beam combining temperature control module. DETAILED DESCRIPTION

[0021] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention is described below with reference to specific embodiments shown in the accompanying drawings.

[0022] like Figure 1-4 A light source assembly is shown, comprising a semiconductor laser 1, a laser driver board 2, a coupling module 3, an optical fiber 4, a fiber combiner 5, a cooling element 6, and a housing 7. The laser driver board 2 controls the semiconductor laser 1 to emit laser light, the coupling module 3 connects the semiconductor laser 1 and the optical fiber 4, and the semiconductor laser 1, the laser driver board 2, and the coupling module 3 are placed in the cooling element 6. The semiconductor laser 1, the laser driver board 2, the coupling module 3, and the cooling element 6 are placed in the housing 7, which has an optical fiber outlet 70. The optical fiber 4 is led out of the optical fiber outlet 70 and is combined by the fiber combiner 5.

[0023] The cooling element 6 is a water cooling element, and the housing 7 is provided with a water inlet 71 and a water outlet 72 , which are connected to the water cooling channel in the cooling element 6 .

[0024] The light source assembly needs to work at an appropriate temperature, so the working temperature of the light source assembly needs to be monitored. In order to avoid damage to the components in the light source assembly, the light source assembly is provided with a real-time temperature monitoring system.

[0025] The real-time temperature monitoring system of the light source assembly includes a beam-combining end monitoring system, which is connected to a general control system. The general control system controls the light source assembly and the real-time temperature monitoring system. The beam-combining end monitoring system is responsible for monitoring the temperature of the beam-combining end of the optical fiber.

[0026] The beam combining end monitoring system includes a beam combining temperature control module and a beam combining temperature probe 21. The beam combining temperature probe 21 is disposed inside the beam combining head 5 or on the side of the beam combining head 5. The beam combining temperature control module receives information from the beam combining temperature probe 21, obtains the temperature of the optical fiber beam combining end, and monitors whether the temperature of the optical fiber beam combining end is abnormal.

[0027] Abnormal fiber bundle end temperatures can be caused by a variety of factors, such as an abnormal focusing lens inserted into the fiber end or an abnormal beam-combining end face of the combiner. Different drive currents driving semiconductor lasers generate different amounts of heat within the combiner, resulting in different temperatures at the bundle end. To better determine whether the bundle end temperature is abnormal, it is best to set different temperature thresholds for different drive currents of the semiconductor lasers.

[0028] In order to obtain different temperature thresholds corresponding to different driving currents of semiconductor lasers, the optical power P of the beam combining head is obtained by a power meter, and the temperature T of the beam combining end is obtained by a beam combining temperature probe. The relationship between the optical power P of the beam combining head and the temperature T of the beam combining end is obtained, and then the different temperature thresholds of different driving currents of different semiconductor lasers are obtained.

[0029] Specifically, by changing the driving current of the semiconductor laser, the optical output power P of the beam combining head is obtained through the power meter, and the temperature T of the beam combining end is obtained through the beam combining temperature probe. For example: setting the driving currents of n different semiconductor lasers, respectively obtaining the corresponding optical output power of the beam combining head and the temperature of the beam combining end, first setting the driving current of the semiconductor laser to I1, measuring the optical output power P1 of the beam combining head through the power meter, and obtaining the temperature T1 of the beam combining end through the beam combining temperature probe; then setting the driving current of the semiconductor laser to I2, measuring the optical output power P2 of the beam combining head at this time through the power meter, and measuring the temperature T2 of the beam combining end at this time through the beam combining temperature probe; and so on, until the driving current of the semiconductor laser is set to I n , the optical power P of the beam combiner is measured by a power meter n , obtain the temperature T of the beam combining end through the beam combining temperature probe n . Obtain the optical output power of the beam combiner and the temperature of the beam combiner end corresponding to the driving current of n different semiconductor lasers. Based on the corresponding relationship between the optical output power P of the n-combination beam combiner and the temperature T of the beam combiner end, obtain the relationship between the two: T= kx LnP+ b, where k and b are constants. Based on the driving current I of the semiconductor laser and the corresponding optical output power P of the beam combiner, obtain the linear relationship between the two: P=mI+a, where m and a are constants. The relationship between the temperature T of the beam combiner end and the driving current I of the semiconductor laser is T=kx Ln(mI+a)+ b.

[0030] Table 1 below is an example of detection data of a group of light source components.

[0031] Table 1 Light source component output power and beam combining end temperature detection data

[0032]

[0033] like Figure 2As shown, a schematic diagram of the relationship between the optical output power and the temperature of the corresponding beam combining end is shown, as well as a schematic diagram of the relationship between the driving current of the semiconductor laser and the optical output power of the corresponding beam combining head.

[0034] The above test data and illustrations are exemplary only. Different numbers of semiconductor lasers in the light source assembly and different external ambient temperatures of the light source assembly will affect the measured values, thereby affecting the values of k, b, m, and a.

[0035] The beam combining temperature control module includes a beam combining end temperature acquisition unit, a beam combining end constant temperature setting unit and a beam combining end temperature abnormality judgment unit.

[0036] The beam combining end temperature acquisition unit obtains information from the beam combining temperature probe 21 and acquires the real-time acquisition temperature Ts.

[0037] The beam combining end constant temperature setting unit obtains the corresponding beam combining head output power P0=mI0+a based on the set semiconductor laser drive current I0 and the linear relationship P=mI+a between the semiconductor laser drive current I and the corresponding beam combining head output power P, and obtains the corresponding end face temperature T0=kxLnP0+b of the beam combining head based on the relationship T=kxLn(mI+a)+b between the beam combining head output power P and the temperature T of the beam combining end. Alternatively, the corresponding end face temperature T0=kxLn(mI0+a)+b of the beam combining head is obtained directly based on the relationship T=kxLn(mI+a)+b between the temperature T of the beam combining end and the semiconductor laser drive current I. The end face temperature T0 is the standard constant temperature corresponding to the semiconductor laser drive current I0.

[0038] The temperature anomaly determination unit at the beam combining end receives the real-time temperature Ts collected by the beam combining end temperature acquisition module and the standard constant temperature T0 set by the beam combining end constant temperature setting module. It determines whether the real-time temperature at the beam combining end is greater than the standard constant temperature T0. If Ts > T0, it then determines whether the difference between the real-time temperature Ts and the standard constant temperature T0 is greater than the fiber's tolerable temperature variation ΔT. If (Ts – T0) > ΔT, an anomaly is determined and the anomaly information is fed back to the master control system. ΔT is the fiber's tolerable temperature variation (temperature change) relative to the standard constant temperature T0, as measured experimentally. T0 + ΔT is the beam combining end temperature threshold. Alternatively, the collected temperature Ts can be directly compared with the beam combining end temperature threshold T0 + ΔT. If the collected temperature Ts is greater than the beam combining end temperature threshold T0 + ΔT, an anomaly is determined and the anomaly information is fed back to the master control system. Using the fiber's tolerable temperature variation ΔT allows the temperature inside the beam combining head to fluctuate within a normal range while preventing damage to the fiber.

[0039] The beam combining end constant temperature setting unit obtains different beam combining end standard constant temperatures according to different driving currents. The beam combining end temperature abnormality judgment unit sets temperature thresholds corresponding to different driving currents according to the end surface temperature, so as to more accurately judge the tolerable temperature of the beam combining end.

[0040] The overall control system receives abnormal information from the beam combining end monitoring system and controls the semiconductor laser to shut down to prevent the light source assembly from overheating and causing damage to the components of the light source assembly due to excessive temperature. At the same time, the relevant components are inspected and certified after they return to normal, and then resume use.

[0041] The real-time temperature monitoring system of the light source assembly further includes a water cooling monitoring system, which is connected to the overall control system and is used to monitor the temperature of the semiconductor laser end.

[0042] The water-cooling monitoring system includes a water-cooling temperature control module 10, an inlet water temperature probe 11, and an outlet water temperature probe 12. The inlet water temperature probe 11 is used to detect the temperature of the water inlet end of the water-cooling component, and the outlet water temperature probe 12 is used to detect the temperature of the water outlet end of the water-cooling component. The water-cooling temperature control module 10 is connected to the inlet water temperature probe 11 and the outlet water temperature probe 12 to obtain the inlet and outlet temperatures of the water-cooling component 6 and monitor whether the inlet and outlet temperatures are abnormal.

[0043] The water inlet temperature probe 11 is arranged at the water inlet end of the cooling element, the water outlet temperature probe 12 is arranged at the water outlet end of the cooling element, and the water cooling temperature control module is integrated on the laser driving board.

[0044] The water-cooling temperature control module 10 includes an inlet water temperature acquisition unit, an inlet water temperature abnormality judgment unit, an outlet water temperature acquisition unit, and an outlet water temperature abnormality judgment unit.

[0045] The water inlet temperature acquisition unit obtains information from the water inlet temperature probe 11, obtains the real-time water inlet temperature Qs, and outputs the real-time water inlet temperature Qs to the water inlet temperature abnormality judgment unit. The water inlet temperature abnormality judgment unit receives the real-time water inlet temperature Qs and compares it with the set water inlet temperature threshold Q0. If the real-time water inlet temperature Qs is greater than the water inlet temperature threshold Q0, the water inlet temperature abnormality judgment unit outputs a water inlet temperature abnormality signal to the overall control system.

[0046] The outlet water temperature acquisition unit obtains information from the outlet water temperature probe 12, obtains the real-time outlet water temperature Rs, and outputs the real-time outlet water temperature Rs to the outlet water temperature abnormality judgment unit. The outlet water temperature abnormality judgment unit receives the real-time outlet water temperature Rs and compares it with the set outlet water temperature threshold R0. If the real-time outlet water temperature Rs is greater than the outlet water temperature threshold R0, the outlet water temperature abnormality judgment unit outputs a water temperature abnormality signal to the overall control system.

[0047] The overall control system receives abnormality information from the water-cooled temperature control module and controls the semiconductor laser to shut down. It also checks related components and, after returning to normal operation, conducts inspection and authentication before resuming operation. The water-cooled temperature control module can further detect temperature anomalies at the semiconductor laser end.

Claims

1. A method for real-time temperature monitoring of a light source assembly, characterized in that: By detecting the light source component, the corresponding relationship between the driving current I of the semiconductor laser and the temperature T of the beam combining end is obtained; Based on the correspondence between the driving current I of the semiconductor laser and the temperature T of the beam combining end, the corresponding standard constant temperature is obtained according to the set driving current of the semiconductor laser; a temperature threshold is set according to the standard constant temperature, and the temperature threshold includes the standard constant temperature and the temperature variation that the optical fiber can withstand, which is the sum of the standard constant temperature and the temperature variation that the optical fiber can withstand; the real-time beam combining end temperature of the light source assembly is obtained and compared with the temperature threshold to determine whether the beam combining end temperature is abnormal.

2. The method for real-time temperature monitoring of a light source assembly according to claim 1, wherein: The method for detecting the correspondence between the driving current I and the temperature T of the beam combining end of the semiconductor laser is to set the driving current of n different semiconductor lasers and obtain the optical power P of the beam combining head and the temperature T of the beam combining end corresponding to each driving current.

3. The method for real-time temperature monitoring of a light source assembly according to claim 2, wherein: According to the optical output power P of the beam combining head and the temperature T of the beam combining end corresponding to n groups of driving currents I, the relationship between the optical output power P of the beam combining head and the temperature T of the beam combining end, the relationship between the optical output power P and the driving current I, and the relationship between the temperature T of the beam combining end and the driving current I are obtained.

4. The method for real-time temperature monitoring of a light source assembly according to claim 3, wherein: The relationship between the optical power P of the beam combiner and the corresponding temperature T at the beam combiner end is T= kx LnP+ b, where k and b are constants; the relationship between the drive current I and the corresponding optical power P of the beam combiner is P=mI+a, where m and a are constants; the relationship between the temperature T at the beam combiner end and the drive current I of the semiconductor laser is T= kx Ln(mI+a)+ b.

5. The method for real-time temperature monitoring of a light source assembly according to claim 1, wherein: When judging whether the temperature of the beam combining end is abnormal, the collected real-time beam combining end temperature is compared with the standard constant temperature to judge whether the real-time beam combining end temperature is greater than the standard constant temperature. When the real-time beam combining end temperature is greater than the standard constant temperature, it is further judged whether the difference between the real-time beam combining end temperature and the standard constant temperature is greater than the temperature variation that the optical fiber can withstand. If the difference between the real-time beam combining end temperature and the standard constant temperature is greater than the temperature variation that the optical fiber can withstand, it is judged that an abnormality has occurred and the abnormal information is fed back to the overall control system.

6. The method for real-time temperature monitoring of a light source assembly according to claim 1, wherein: When determining whether the temperature at the beam combining end is abnormal, the real-time temperature at the beam combining end is compared with the temperature threshold at the beam combining end. When the real-time temperature at the beam combining end is greater than the temperature threshold at the beam combining end, it is determined to be abnormal and the abnormal information is fed back to the overall control system. The beam combining end threshold is the sum of the standard constant temperature and the temperature variation that the optical fiber can withstand.

7. The method for real-time temperature monitoring of a light source assembly according to claim 1, wherein: The inlet and outlet water temperatures of the light source component cooling parts are collected in real time and compared with the set corresponding inlet or outlet water temperature thresholds. If the inlet or outlet water temperature thresholds are greater than the corresponding inlet or outlet water temperature thresholds, an abnormal signal is output to the overall control system.

8. A real-time monitoring system using the method for real-time temperature monitoring of a light source assembly according to claims 1-7, wherein the light source assembly comprises a semiconductor laser, a laser driver board, a coupling module, an optical fiber, a fiber combiner, a cooling element, and a housing; the laser driver board controls the semiconductor laser to emit laser light; the coupling module connects the semiconductor laser and the optical fiber; the semiconductor laser and the coupling module are placed in the cooling element; the housing has an optical fiber outlet; the optical fiber is led out from the optical fiber outlet; and the optical fiber is combined by a fiber combiner, characterized in that: The real-time monitoring system of the light source assembly includes a beam combining temperature control module and a beam combining temperature probe. The beam combining temperature probe is arranged at the beam combining head, and the beam combining temperature probe is connected to the beam combining temperature control module. The beam combining temperature control module includes a beam combining end temperature acquisition unit, a beam combining end constant temperature setting unit and a beam combining end temperature abnormality judgment unit. The beam combining end temperature acquisition unit obtains information from the beam combining temperature probe; the beam combining end constant temperature setting unit is used to obtain the corresponding standard constant temperature according to the set driving current of the semiconductor laser; the beam combining end temperature abnormality judgment unit is used to judge whether the real-time beam combining end temperature obtained by the beam combining end temperature acquisition unit from the beam combining temperature probe exceeds the temperature threshold set according to the standard constant temperature.

9. The real-time monitoring system for a light source assembly according to claim 8, characterized in that: The beam combining temperature probe is arranged inside or on the side of the beam combining head.

10. The real-time monitoring system for a light source assembly according to claim 8, characterized in that: The real-time monitoring system of the light source assembly also includes a water-cooled temperature control module, an outlet water temperature probe and an inlet water temperature probe. The outlet water temperature probe and the inlet water temperature probe are connected to the water-cooled temperature control module. The outlet water temperature probe and the inlet water temperature probe are used to collect the real-time temperatures of the outlet and inlet ends of the water-cooled component. The water-cooled temperature control module is used to determine whether the real-time temperature obtained by the outlet water temperature probe and the inlet water temperature probe exceeds the set corresponding outlet water temperature threshold or inlet water temperature threshold.

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