Laser diode state monitoring method and system based on multi-parameter fusion

Abstract

The invention relates to the technical field of photoelectric detection, in particular to a laser diode state monitoring method and system based on multi-parameter fusion, and the method comprises the steps: carrying out the laying and collection of a plurality of parameters based on the working condition of a laser diode, including current, temperature and optical feedback signals, and carrying out the dynamic fusion to construct a damage index; establishing a grading early warning mechanism, correspondingly setting a judgment threshold value, and triggering early warning in combination with the damage index; the temperature is detected periodically, parameter drift influenced by the temperature is corrected based on a damage index, and state monitoring of the laser diode is achieved; by dynamically fusing a plurality of parameters of current, temperature and optical feedback signals, a multi-dimensional damage index is established, so that the influence of a plurality of indexes on laser diode damage is synthesized, and the recognition rate of early damage is improved; and establishing a grading early warning mechanism from a slight state to a serious state, making a corresponding early warning response, and advancing fault recognition of the laser diode to a reversible stage.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photoelectric detection, in particular to a laser diode state monitoring method and system based on multi-parameter fusion. BACKGROUND

[0002] The laser diode is easy to be damaged in use, and there are four main reasons. Among them, thermal runaway is the key factor of the laser diode damage. The working temperature is too high, which can accelerate the aging, especially when the internal temperature rises sharply due to poor heat dissipation. Current impact can cause irreversible damage, especially in the case of current out of control at the moment of starting or stopping. Mechanical stress caused by installation vibration or external impact can damage the internal structure of the laser diode and cause damage. Or with the long-term use of the laser diode, the performance decays, which affects its stability and life. In order to ensure the stability of the whole system in operation, the detection method of the damaged laser diode is proposed.

[0003] However, the existing detection method usually uses traditional methods such as multimeter resistance value, current estimation, etc. There are some defects. It only depends on single indicators such as resistance or current. For example, it is determined that the forward resistance is greater than a certain threshold value to judge aging, or threshold current mutation detection is used for diagnosis. It cannot comprehensively evaluate the multi-factor coupling damage of thermal runaway, current impact and material aging. Early damage is easy to be missed, and the early damage missed rate is as high as 40% or more. Therefore, the single-dimensional detection has strong limitations. And the existing technology usually triggers an alarm when the light power drops sharply or the threshold current increases sharply, such as when the current is greater than 100mA. At this time, the laser diode has entered the irreversible damage stage. Early intervention cannot be realized, and the alarm failure is lagging. It is not possible to make preparations in advance to prevent the damage of the laser diode. In addition, single parameter is easy to be disturbed by instantaneous current fluctuation, external temperature change and other interference, and it is easy to misjudge normal fluctuation as permanent damage and other false information, which affects the accuracy of monitoring. SUMMARY

[0004] In order to solve the technical problems of single-dimensional detection limitation, fault early warning lag and high misjudgment rate caused by environmental interference in the existing method for monitoring the laser diode, the purpose of the present application is to provide a laser diode state monitoring method based on multi-parameter fusion. The technical scheme adopted is as follows:

[0005] Based on the working condition of the laser diode, multiple parameters including current, temperature and optical feedback signal are collected and dynamically fused to construct a damage index;

[0006] A hierarchical early warning mechanism is established, and a judgment threshold is set correspondingly, and the early warning is triggered in combination with the damage index;

[0007] Periodically detect the temperature, correct the parameter drift affected by the temperature based on the damage index, and realize the state monitoring of the laser diode.

[0008] Preferably, the laser diode is electrically connected with a power supply, a constant current source driving circuit, an optical power acquisition circuit and a thermocouple acquisition temperature circuit, respectively, the power supply is used for power supply, the optical power acquisition circuit and the thermocouple acquisition temperature circuit acquire parameters of the laser diode and transmit to the MCU module for processing, and after processing, the constant current source driving circuit is used for returning the laser diode, forming a feedback system.

[0009] Preferably, based on the working condition of the laser diode, a plurality of parameters are acquired, including current, temperature and optical feedback signal, and a damage index is dynamically fused and constructed, including:

[0010] The threshold current is monitored based on the feedback system, the optical power feedback value is captured by the laser diode, and the shell temperature of the laser diode is obtained by the thermocouple acquisition temperature circuit;

[0011] The initial calibration value of the threshold current, the optical power and the safety temperature threshold value are acquired respectively, and the current, the temperature and the optical feedback signal are dynamically fused and combined with the acquired plurality of parameters to construct the damage index.

[0012] Preferably, the calculation formula of the damage index is:

[0013]

[0014]

[0015]

[0016] Among them, Damage index; , , All represent weight coefficients; Current change amount; Threshold current in operation; Initial calibration value of threshold current; Optical power change amount; Optical power feedback value in operation; Initial calibration value of optical power; Acquired shell temperature of laser diode; Limit temperature of laser diode; Safety temperature threshold value.

[0017] Preferably, a hierarchical early warning mechanism is established, and a judgment threshold value is set correspondingly, and the early warning is triggered in combination with the damage index, including:

[0018] Primary early warning, intermediate early warning and terminal early warning are constructed respectively, and the judgment threshold value is set correspondingly.

[0019] When the damage index is greater than and equal to the judgment threshold of the primary early warning, a reminder is given and calibration is performed;

[0020] When the damage index is greater than and equal to the judgment threshold of the intermediate early warning, current limiting protection is activated;

[0021] When the damage index is greater than and equal to the judgment threshold of the final early warning, it is determined that permanent damage has occurred and the output is turned off.

[0022] Preferably, the temperature is periodically detected, the parameter drift affected by the temperature is corrected based on the damage index, and the state monitoring of the laser diode is realized, including:

[0023] A corresponding table is established based on the temperature and the current, and the corresponding table is pre-stored in the MCU module;

[0024] The temperature is periodically detected, the corresponding current is found by the MCU module according to the current temperature through the corresponding table, the threshold current collected in the working of the laser diode is replaced, the parameter drift affected by the temperature is corrected, and the state monitoring of the laser diode is realized.

[0025] To solve the above problems, the application also provides: a laser diode state monitoring system based on multi-parameter fusion, the system comprising:

[0026] A data acquisition and processing module is configured to: collect a plurality of parameters based on the working condition of the laser diode, and construct a damage index through dynamic fusion of the current, temperature and optical feedback signal;

[0027] A warning module is configured to: establish a hierarchical early warning mechanism, set corresponding judgment thresholds, and trigger early warning in combination with the damage index;

[0028] A data correction module is configured to: periodically detect the temperature, correct the parameter drift affected by the temperature based on the damage index, and realize the state monitoring of the laser diode.

[0029] The application has the following beneficial effects:

[0030] According to the multiple parameters of the current, temperature and light feedback signals collected for the laser diode, the changes of the internal electronic activities are accurately captured, and dynamic fusion is carried out, a multi-dimensional damage index is established, the influence of multiple indexes on the laser diode damage is comprehensively considered, the recognition rate of early damage is improved, and the problem of one-sidedness of single parameter is solved; a hierarchical early warning mechanism is established, from the slight state to the serious state, and the corresponding early warning response is made, so that problems of different levels can be treated in time, and the failure recognition of the laser diode is advanced to the reversible stage; based on the established damage index, the weight is dynamically adjusted adaptively, the instantaneous interference is suppressed, and the reliability of the monitoring is improved; in the overall technology, the material aging caused by time drift is corrected through the construction of the damage index, and the temperature is detected periodically to correct the parameter drift influenced by the temperature, so that the state monitoring of the laser diode is realized. BRIEF DESCRIPTION OF DRAWINGS

[0031] In order to more clearly illustrate the technical solutions and advantages of the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0032] Figure 1 The structure schematic block diagram of a feedback system of a laser diode state monitoring method based on multi-parameter fusion provided by an embodiment of the present application is shown in the figure.

[0033] Figure 2 The schematic diagram of a constant current source driving circuit of a laser diode state monitoring method based on multi-parameter fusion provided by an embodiment of the present application is shown in the figure.

[0034] Figure 3 The schematic diagram of a light power collection circuit of a laser diode state monitoring method based on multi-parameter fusion provided by an embodiment of the present application is shown in the figure.

[0035] Figure 4 The schematic diagram of a thermocouple temperature collection circuit of a laser diode state monitoring method based on multi-parameter fusion provided by an embodiment of the present application is shown in the figure.

[0036] Figure 5 The circuit schematic diagram of an MCU module of a laser diode state monitoring method based on multi-parameter fusion provided by an embodiment of the present application is shown in the figure. DETAILED DESCRIPTION

[0037] In order to further illustrate the technical means and effects taken by the present application to achieve the predetermined inventive purpose, the specific implementation, structure, features and effects of a multi-parameter fusion-based laser diode state monitoring method and system according to the present application are described in detail as follows in combination with the drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. In addition, the specific features, structures or characteristics in one or more embodiments can be combined in any suitable form.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs.

[0039] The specific scheme of a multi-parameter fusion-based laser diode state monitoring method and system provided by the present application is described in detail below in combination with the drawings.

[0040] The present application provides a multi-parameter fusion-based laser diode state monitoring method, which comprises the following steps:

[0041] Step S1: Collecting multiple parameters including current, temperature and optical feedback signal based on the working condition of the laser diode, and dynamically fusing and constructing a damage index;

[0042] Step S2: Establishing a hierarchical early warning mechanism and corresponding setting of judgment threshold, and triggering early warning combined with the damage index;

[0043] Step S3: Periodically detecting temperature, correcting temperature-affected parameter drift based on the damage index, and realizing state monitoring of the laser diode.

[0044] For better illustration, a laser diode is a laser device that uses semiconductor material as gain medium; it injects current into semiconductor material to make electrons jump to high energy level, then releases energy to produce laser; it is based on the stimulated radiation phenomenon in semiconductor physics, and through precise control of semiconductor material doping and structure design, it can realize laser output of different wavelengths and powers; it is widely used in industrial manufacturing, medical and military and scientific instruments, etc. However, it is easy to be damaged in use, and the main reasons are four categories. First, high working temperature accelerates aging or poor heat dissipation causes internal temperature to rise sharply, causing thermal runaway and reducing performance. Second, thermal damage caused by excessive current or voltage fluctuation. Third, physical damage caused by mechanical stress or external impact. Finally, aging and degradation of semiconductor material during long-term use.

[0045] The prior art has certain defects for detecting the laser diode, and therefore the application provides a laser diode state monitoring method based on multi-parameter fusion, which comprehensively analyzes multiple parameters such as current, temperature and optical power, realizes real-time monitoring and accurate evaluation of the operating state of the laser diode, effectively improves the monitoring accuracy and reliability, and ensures the stable operation of the laser diode under various complex working conditions.

[0046] Referring to Figure 1 , which shows a feedback system structure schematic block diagram of a laser diode state monitoring method based on multi-parameter fusion provided by the first embodiment of the application.

[0047] Further, the laser diode is electrically connected with a power supply, a constant current source driving circuit, an optical power acquisition circuit and a thermocouple temperature acquisition circuit, the power supply is used for power supply, the optical power acquisition circuit and the thermocouple temperature acquisition circuit acquire parameters of the laser diode and transmit to the MCU module for processing, and after processing, the laser diode is returned through the constant current source driving circuit to form a feedback system.

[0048] It is explained that the power supply provides stable current to ensure the normal work of the laser diode; the optical power acquisition circuit monitors the light intensity emitted by the laser diode in real time, and the thermocouple temperature acquisition circuit accurately measures the working temperature of the laser diode by using a high-sensitivity thermocouple element; the related parameters acquired by the two circuits are transmitted to the MCU (Microcontroller Unit, MCU) module for comprehensive processing, and after processing, the MCU module adjusts the current output through the constant current source driving circuit to optimize the performance of the laser diode, and a feedback system is constructed, so that the whole circuit can be adaptively adjusted to ensure the operation of the laser diode in the best state.

[0049] Please refer to Figures 2-5 For better illustration, the application provides a circuit schematic diagram for constructing a feedback system, wherein, Figure 2 The constant current source driving circuit is shown in the figure, the MCU_DAC output voltage changes, that is, the reference voltage of the MCU module output operational amplifier, the operational amplifier (AP4310) adjusts the output voltage according to the difference between the reference voltage and the feedback voltage, changes the base current of the transistor Q1, and then adjusts the current flowing through the laser diode to change the voltage of the resistor R5, and feeds back to the negative input end of the operational amplifier, forms a negative feedback, that is, adjusts the output through the operational amplifier, stabilizes the current flowing through the laser diode, and ensures the stable work of the laser diode.

[0050] Figure 3The light power acquisition circuit is shown, the laser diode (PD) converts the received optical signal into a current signal, the weak current signal generated by the laser diode is amplified by the operational amplifier (AP4310), and then converted into a voltage signal, finally input into the MCU module through the resistance R10, realizing the acquisition and digitization of the light power.

[0051] Figure 4 The thermocouple acquisition temperature circuit is shown, which uses ADS1118 analog-to-digital converter (ADC) to read the voltage signal of the thermocouple and convert it into a digital signal for the MCU module to read; wherein the thermocouple input end, i.e. TIN+ and TIN-, is used to sense the temperature change of the laser diode to generate a corresponding voltage signal, and the whole laser diode is collected and monitored by accurately measuring the small voltage change generated by the thermocouple.

[0052] Figure 5 The data processing circuit of the MCU module is shown, which is used for comprehensive processing of the data of the light power acquisition circuit and the thermocouple acquisition temperature circuit, to ensure the accuracy and reliability of the data, and to ensure the stable operation of the whole feedback system.

[0053] Further, in step S1, comprising:

[0054] Step S11: based on the laid feedback system, monitor the threshold current, capture the light power feedback value through the laser diode, and obtain the tube shell temperature of the laser diode by using the thermocouple acquisition temperature circuit;

[0055] Step S12: respectively obtain the initial calibration value of the threshold current, the light power and the safety temperature threshold, combine the collected multiple parameters, dynamically fuse the current, temperature and light feedback signal, and construct the damage index.

[0056] It is explained that the multiple acquisition circuits in the feedback system formed based on the foregoing steps synchronously acquire the working current, the threshold current, the light power feedback value and the tube shell temperature, avoiding the data limitation problem caused by only measuring the current or resistance, and then constructing the damage index to quantify the damage of the laser diode.

[0057] Further, in step S12, the calculation formula corresponding to the damage index is:

[0058]

[0059]

[0060]

[0061] Among them, Damage index. , , represent weight coefficients; represents the change of current; represents the threshold current in operation; represents the initial calibration value of the threshold current; represents the change of optical power; represents the optical power feedback value in operation; represents the initial calibration value of the optical power; represents the collected package temperature of the laser diode; represents the limit temperature of the laser diode; represents the safety temperature threshold.

[0062] It can be explained that, represents the initial calibration value of the threshold current, i.e. the data obtained for a normal brand-new undamaged laser diode that has just started to be used, represents the threshold current in operation, the data of which will increase with the use of the laser diode due to material aging and the like, and therefore based on the change of current reflects the intrinsic characteristics of the laser diode due to material aging or damage, and is extremely sensitive to early damage, and can identify potential problems at an early stage. represents the initial calibration value of the optical power, represents the optical power feedback value in operation, which is the standard optical power output value (unit: mW) monitored by the built-in photo diode (PD) of the laser diode, and the change of optical power is used to quantify the degree of attenuation of the current optical power feedback value, and is one of the core indicators for determining the aging or damage of the laser diode.

[0063] is the real-time temperature obtained by the thermocouple temperature acquisition circuit, represents the safety temperature threshold, which represents the upper limit temperature of the laser diode without damage under long-term operation, represents the limit temperature of the laser diode, i.e. the critical point at which the laser diode is permanently damaged; in actual applications, the safety temperature threshold must be strictly lower than the limit temperature, and therefore usually based on 80%~90% of the limit temperature to ensure that there is enough temperature buffer interval, prevent the temperature from approaching or exceeding the limit temperature due to unexpected situations, avoid damage or safety hazards of the laser diode, improve the reliability of the laser diode, and prolong the service life.

[0064] It can be understood that the damage early warning of the traditional monitoring method has a lag, that is, generally irreversible damage occurs to trigger early warning, which leads to the inability to take timely measures and aggravates the damage of the laser diode; therefore, the application quantifies the early risk by a hierarchical early warning mechanism combined with the damage index, aims to identify potential problems and intervene in advance, can only accurately assess the damage degree, and can also adjust the response strategy according to different risk levels; and the response speed is improved to the millisecond level to ensure that the damage can be quickly responded to at the early stage, effectively reducing the loss and maintenance cost.

[0065] Further, in step S2, the following steps are included:

[0066] The primary early warning, the intermediate early warning and the final early warning are respectively constructed, and the judgment thresholds are sequentially set;

[0067] When the damage index is greater than and equal to the judgment threshold of the primary early warning, a reminder is given and calibration is performed;

[0068] When the damage index is greater than and equal to the judgment threshold of the intermediate early warning, the current limiting protection is activated;

[0069] When the damage index is greater than and equal to the judgment threshold of the final early warning, it is determined that the permanent damage occurs and the output is turned off.

[0070] Specifically, in the embodiment, a three-level intelligent early warning mechanism is established, and the primary early warning, the intermediate early warning and the final early warning are respectively determined according to the index of the damage index; wherein the judgment threshold of the primary early warning is 0.5, when the damage index is greater than and equal to 0.5, an acoustic and optical reminder is given to the staff to perform parameter calibration to avoid complete failure of the laser diode, slow down the damage and reduce the loss after complete damage; the judgment threshold of the intermediate early warning is 0.8, when the damage index is greater than and equal to 0.8, the current limiting protection is activated to reduce the current to a safe threshold, and the staff is prompted to pay attention to the state of the laser diode; the judgment threshold of the final early warning is 1, when the damage index is greater than and equal to 1, it is determined that the permanent damage occurs and the output is turned off, and the staff is reminded to replace the laser diode to ensure the normal operation of the whole work.

[0071] It can be understood that the correction of time drift and temperature drift is to eliminate the influence on the accuracy of the damage index, that is, the temperature drift correction , and the time drift correction ; and in the foregoing construction of the damage index, the material aging accompanied by the time drift has been reflected in the damage index, which belongs to the part of constructing the damage, therefore, in order to prevent the influence of the temperature drift on the damage accuracy, the threshold current the influence of temperature. In addition, the traditional monitoring calibration mechanism usually relies on manual periodic calibration or no calibration mechanism in general, so the calibration mechanism is introduced to realize automatic calibration compensation and assist in improving the accuracy of the damage index.

[0072] Further, in step S3, comprising:

[0073] Step S31: Establish a corresponding table based on temperature and current, and prestore the corresponding table in the MCU module;

[0074] Step S32: Periodically detect the temperature, and the MCU module looks up the corresponding current according to the current temperature through the corresponding table, and replaces the threshold current collected in the working laser diode, corrects the parameter drift affected by temperature, and realizes the state monitoring of the laser diode.

[0075] It is explained that based on the feedback system established as described above, an automatic calibration compensation mechanism is constructed, that is, a corresponding table of temperature-current is established, for example, taking every 1℃ in the range of-40~85℃ as a corresponding current value, forming a temperature-current corresponding table, and pre-storing the table in the MCU module. When the damage index is determined in the working laser diode, the corresponding current is looked up according to the current working temperature to replace the monitored threshold current, and then the damage index after parameter update is obtained, that is, the influence of temperature change on the threshold current is corrected, so that the acquisition of the damage index is more accurate.

[0076] For better illustration, a laser diode state monitoring method based on multi-parameter fusion is proposed in the present application to verify effectiveness, and HGLD-980TO5.6-ZSP type laser diode is used, and a feedback system is arranged based on the laser diode to collect parameters in working, specifically, based on the injection of 10mA current at room temperature 25℃, the initial calibration value of threshold current is recorded as , and the initial calibration value of feedback optical power is ; the laser diode starts to work, and an 80mA working current is applied for 120s, the real-time temperature of the laser diode shell is obtained by the thermocouple temperature acquisition circuit , and the real-time threshold current is calibrated by using the second derivative method , that is, the current in working is twice differentiated to identify the change of current change rate and determine the threshold current; the optical power acquisition circuit acquires the optical power feedback value in working based on the built-in photodiode in the laser diode , and the sampling frequency is 10Hz; preferably, the weight coefficients are respectively 、 、 , wherein the limit temperature is ℃, and the safety temperature threshold is ℃; and then the damage index is calculated according to the real-time collected parameters .

[0077] It can be explained that when ℃, , , greater than and equal to the judgment threshold value 0.5 of the primary early warning, so the primary early warning is triggered, and the automatic calibration compensation mechanism is started; when ℃, , , greater than and equal to the judgment threshold value 0.8 of the intermediate early warning, at this time the current is limited to 50mA to prevent further damage to the laser diode; when , , greater than and equal to the final early warning judgment threshold value 1, at this time the laser diode is determined to be permanently damaged and the output is closed; that is, the false rejection rate is reduced by the laser diode state monitoring method based on multi-parameter fusion provided by the application, thereby improving the recognition rate of early damage.

[0078] The second embodiment of the application provides a laser diode state monitoring system based on multi-parameter fusion, which comprises:

[0079] A data acquisition and processing module is configured to collect multiple parameters based on the working conditions of the laser diode, and to construct a damage index by dynamically fusing current, temperature and optical feedback signals.

[0080] A warning module is configured to establish a hierarchical early warning mechanism and set corresponding judgment thresholds, and to trigger early warning in combination with the damage index.

[0081] A data correction module is configured to periodically detect temperature, correct parameter drift affected by temperature based on the damage index, and realize state monitoring of the laser diode.

[0082] It can be understood that the modules of the laser diode state monitoring system based on multi-parameter fusion need to use the laser diode state monitoring method based on multi-parameter fusion provided by any one of the preceding embodiments when in operation, so whether the method is integrated with any module of the data acquisition and processing module, the warning module and the data correction module or configured with different hardware to produce similar functions to the effects achieved by the application, all belong to the protection scope of the application; the system and the laser diode state monitoring method based on multi-parameter fusion provided by any one of the preceding embodiments have the same beneficial effects, which will not be described here.

[0083] It should be noted that the sequence of the above embodiments is only for description, and does not represent the advantages and disadvantages of the embodiments. The processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are possible or can be advantageous.

[0084] The various embodiments described in this specification are presented by way of example, and each embodiment is not necessarily composed of all features described with respect to other embodiments.

Claims

1. A method for laser diode condition monitoring based on multi-parameter fusion, characterized in that, The method comprises: Based on the working condition of the laser diode, multiple parameters including current, temperature and optical feedback signal are collected and dynamically fused to construct a damage index; A hierarchical early warning mechanism is established, and corresponding judgment thresholds are set, and the early warning is triggered in combination with the damage index; Periodically detect the temperature, correct the parameter drift affected by the temperature based on the damage index, and realize the state monitoring of the laser diode.

2. The method of claim 1, wherein the method is based on multi-parameter fusion. The laser diode is electrically connected with a power supply, a constant current source driving circuit, an optical power acquisition circuit and a thermocouple temperature acquisition circuit, the power supply is used for power supply, the optical power acquisition circuit and the thermocouple temperature acquisition circuit acquire parameters of the laser diode and transmit to the MCU module for processing, and after processing, the laser diode is returned through the constant current source driving circuit to form a feedback system.

3. The method of claim 2, wherein the method further comprises: Based on the working condition of the laser diode, multiple parameters including current, temperature and optical feedback signal are collected and dynamically fused to construct a damage index, including: Based on the monitoring threshold current of the feedback system, the optical power feedback value is captured by the laser diode, and the tube shell temperature of the laser diode is obtained by the thermocouple temperature acquisition circuit; The initial calibration value of the threshold current, the optical power and the safety temperature threshold value are obtained respectively, and in combination with the collected multiple parameters, the current, temperature and optical feedback signal are dynamically fused to construct a damage index.

4. The method of claim 3, wherein the method further comprises: The corresponding calculation formula of the damage index is: ； ； ； wherein, represents an injury index; , , each represents a weight coefficient; represents a change amount of current; represents a threshold current in operation; represents an initial calibration value of the threshold current; represents a change amount of optical power; represents an optical power feedback value in operation; represents an initial calibration value of the optical power; represents a package temperature of the collected laser diode; represents a limit temperature of the laser diode; represents a safety temperature threshold.

5. The method of claim 1, wherein the method is based on multi-parameter fusion. A hierarchical early warning mechanism is established, and corresponding judgment thresholds are set, and the early warning is triggered in combination with the damage index, including: Primary, secondary and final early warnings are constructed respectively, and corresponding judgment thresholds are set in turn; When the damage index is greater than and equal to the judgment threshold of the primary early warning, a reminder is given and calibration is performed; When the damage index is greater than and equal to the judgment threshold of the secondary early warning, the current limiting protection is activated; When the damage index is greater than and equal to the judgment threshold of the final early warning, it is determined as permanent damage and the output is turned off.

6. The method of claim 3, wherein the method further comprises: Periodically detect the temperature, correct the parameter drift affected by the temperature based on the damage index, and realize the state monitoring of the laser diode, including: Based on the temperature and the current, a corresponding table is established, and the corresponding table is pre-stored in the MCU module; Periodically detect the temperature, and the MCU module finds the corresponding current according to the current temperature through the corresponding table, replaces the collected threshold current in the working of the laser diode, corrects the parameter drift affected by the temperature, and realizes the state monitoring of the laser diode.

7. A multi-parameter fusion based laser diode condition monitoring system, characterized in that, The system comprises: A data acquisition and processing module is configured to collect multiple parameters based on the working condition of the laser diode, and dynamically fuse a damage index through current, temperature and optical feedback signal; An early warning module is configured to establish a hierarchical early warning mechanism, and set corresponding judgment thresholds, and trigger early warning in combination with the damage index; A data correction module is configured to periodically detect the temperature, correct the parameter drift affected by the temperature based on the damage index, and realize the state monitoring of the laser diode.

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