A Method and System for Predicting the Lifetime of EDFA-Pumped Lasers Based on Dynamic Stress Accumulation

Abstract

This invention discloses a method for predicting the lifetime of an EDFA-pumped laser based on dynamic stress accumulation, comprising: real-time acquisition of the pump laser's driving current, forward voltage drop, backlight power, and case temperature during operation; obtaining the calibrated thermal resistance of the pump laser and calculating the instantaneous junction temperature by combining the driving current, forward voltage drop, backlight power, and case temperature; acquiring the driving current and instantaneous junction temperature at fixed time intervals and calculating the total damage rate under the current stress condition by combining a total damage rate model; calculating the total accumulated damage in real-time based on the total damage rate and predicting the lifetime based on the real-time calculated total accumulated damage. This invention can sense the dynamic operating stress of the pump laser in real time and achieve high-precision lifetime prediction by accumulating its damage effect.

Description

Technical Field

[0001] This invention relates to the field of optical communication equipment reliability technology, and in particular to a lifetime prediction method and system based on dynamic stress accumulation for pump lasers in erbium-doped fiber amplifiers (EDFAs). Background Technology

[0002] EDFAs are core components of modern optical networks, and their long-term reliability is crucial. The pump laser, as the "heart" of the EDFA, is its primary source of failure. Currently, health management of pump lasers largely remains at the level of static monitoring, such as monitoring whether the drive current and case temperature exceed fixed thresholds.

[0003] The main drawback of existing technology is that:

[0004] 1. Limitations of static models: Even with lifetime predictions, most are based on fixed rated operating conditions or average temperature, using a single Arrhenius model for calculation. This type of model cannot reflect the dynamic current and temperature stresses generated by the laser due to fluctuations in workload during actual operation.

[0005] 2. Insufficient prediction accuracy: Because the dynamic changes in current stress are ignored and the typical thermal resistance values ​​provided by the manufacturer are often used to estimate the junction temperature, the lifetime prediction results are either too optimistic or pessimistic, and the deviation from the actual lifetime is large.

[0006] 3. Lack of real-time capability: It cannot provide quantitative health status indicators that change over time, and maintenance personnel cannot know the accurate remaining lifespan based on actual usage, making it difficult to implement true predictive maintenance. Summary of the Invention

[0007] To address the problem that existing technologies cannot accurately reflect the impact of dynamic operating conditions on lifespan, this invention provides a method and system for predicting the lifespan of an EDFA pump laser based on dynamic stress accumulation. This method can sense the dynamic operating stress of the pump laser in real time and achieve high-precision lifespan prediction by accumulating its damage effects.

[0008] According to one aspect of the present invention, a method for predicting the lifetime of an EDFA-pumped laser based on dynamic stress accumulation is provided, comprising:

[0009] Real-time acquisition of the pump laser's drive current, forward voltage drop, backlight power, and case temperature during operation;

[0010] The calibrated thermal resistance of the pump laser is obtained, and the instantaneous junction temperature is calculated by combining the driving current, forward voltage drop, backlight power and case temperature.

[0011] Drive current and instantaneous junction temperature are collected at fixed time intervals, and the total damage rate is calculated under the current stress condition by combining the total damage rate model.

[0012] Total cumulative damage is calculated in real time based on the total damage rate, and lifetime prediction is performed based on the total cumulative damage calculated in real time.

[0013] As a further technical solution, the calibration of the thermal resistance value of the current pump laser includes:

[0014] The relationship between forward voltage drop and junction temperature is constructed based on the forward voltage drop method, and the parameters in the relationship are calibrated using an in-system calibration strategy to obtain the calibrated relationship.

[0015] Under steady-state conditions of the pump laser, the driving current, forward voltage drop, backlight power, and case temperature were recorded.

[0016] The pump laser driver is repeatedly switched to the small pulse current applied during system calibration, a set of forward voltage drops is tested and recorded, and the average of this set of forward voltage drops is used to obtain the forward voltage drop for calculation.

[0017] Substituting the forward voltage drop used in the calculation into the calibrated relationship, the junction temperature under the current steady-state conditions is obtained;

[0018] The junction temperature under the current steady-state conditions, along with the recorded drive current, forward voltage drop, back light power, and case temperature, are substituted into the thermal resistance calculation expression to obtain the calibrated thermal resistance value.

[0019] As a further technical solution, the expression for calculating the thermal resistance value is as follows:

[0020] ,

[0021] in, For the junction temperature, Shell temperature, For driving current, For positive pressure drop, For comparison before and after, This represents the backlight power.

[0022] As a further technical solution, the thermal resistance calibration of the current pump laser also includes the following before-and-after comparison calibration:

[0023] Establish backlight power With forward output optical power The proportional relationship between them is: ;

[0024] Data collection at multiple output power points and Data was collected and linearly fitted to determine the ratio before and after. .

[0025] As a further technical solution, the system calibration strategy is as follows:

[0026] Multiple calibration point temperatures can be set using the TEC temperature control circuit integrated into the EDFA module.

[0027] When the EDFA is operating in ACC mode, after the case temperature and TEC drive current stabilize, a small pulse current is applied to the pump laser. Under the applied small pulse current condition, the case temperature is approximately equal to the junction temperature, and the relationship between the forward voltage drop and the junction temperature is converted into the relationship between the forward voltage drop and the case temperature.

[0028] The forward pressure drop and shell temperature were tested and recorded at different calibration point temperatures.

[0029] Based on the recorded forward pressure drop and shell temperature at different calibration point temperatures, the parameters of the relationship between forward pressure drop and shell temperature are obtained through linear fitting, and then the parameters of the relationship between forward pressure drop and junction temperature are obtained.

[0030] As a further technical solution, the total damage rate model is as follows:

[0031] ,

[0032] in, All are proportionality constants. The activation energy of the failure mechanism Let be the junction temperature at time t. Let be the pump laser driving current at time t. The current acceleration index.

[0033] As a further technical solution, the total cumulative damage is calculated in real time based on the total damage rate, and lifetime prediction is performed based on the real-time calculated total cumulative damage, including:

[0034] Each time the total damage rate is calculated, damage accumulation is performed, and the variable for each accumulation is... ,in, Total damage rate, For fixed time intervals;

[0035] Real-time calculation of total cumulative damage Thus, lifespan can be predicted. ,in, This represents the initial lifetime of the pump laser.

[0036] According to one aspect of the present invention, a lifetime prediction system for an EDFA-pumped laser based on dynamic stress accumulation is provided, comprising:

[0037] The dynamic stress sensing unit is used to collect drive current, forward voltage drop, back light power and case temperature in real time;

[0038] The data processing unit is used to calculate the instantaneous junction temperature based on the calibrated thermal resistance of the current pump laser, combined with the driving current, forward voltage drop, backlight power and case temperature; to collect the driving current and instantaneous junction temperature at fixed time intervals, and to calculate the total damage rate under the current stress condition by combining the total damage rate model; and to calculate the total cumulative damage in real time based on the total damage rate, and to predict the lifetime based on the total cumulative damage calculated in real time.

[0039] As a further technical solution, the system also includes a thermal resistance calibration unit, used for:

[0040] The relationship between forward voltage drop and junction temperature is constructed based on the forward voltage drop method, and the parameters in the relationship are calibrated using an in-system calibration strategy to obtain the calibrated relationship.

[0041] Under steady-state conditions of the pump laser, the driving current, forward voltage drop, backlight power, and case temperature were recorded.

[0042] The pump laser driver is repeatedly switched to the small pulse current applied during system calibration, a set of forward voltage drops is tested and recorded, and the average of this set of forward voltage drops is used to obtain the forward voltage drop for calculation.

[0043] Substituting the forward voltage drop used in the calculation into the calibrated relationship, the junction temperature under the current steady-state conditions is obtained;

[0044] The junction temperature under the current steady-state conditions, along with the recorded drive current, forward voltage drop, back light power, and case temperature, are substituted into the thermal resistance calculation expression to obtain the calibrated thermal resistance value.

[0045] As a further technical solution, the system also includes a storage unit for:

[0046] Store calibrated thermal resistance values, model parameters, and historical damage data.

[0047] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0048] 1. Achieves true dynamic prediction: This invention uses the real-time changing current and junction temperature as a dynamic stress pair to jointly drive the lifetime prediction model, so that the prediction results can truly reflect the actual lifetime consumption process of the laser as the service load fluctuates.

[0049] 2. Improved prediction accuracy: By using a system-calibrated physical model of thermal resistance and multi-stress coupling, errors caused by individual differences and model simplification are eliminated at the source, upgrading lifetime prediction from "rough estimation" to "precise assessment".

[0050] 3. High practical engineering value: The output SOH and RUL are direct decision-making bases for predictive maintenance. This invention enables maintenance personnel to "see" the degradation process inside devices, providing core technical support for intelligent operation and maintenance and ultra-high reliability assurance of optical networks. Attached Figure Description

[0051] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0052] Figure 1 This is a flowchart illustrating the method for predicting the lifetime of an EDFA-pumped laser based on dynamic stress accumulation, as provided in an embodiment of the present invention.

[0053] Figure 2 This is a schematic diagram of the thermal resistance calibration process provided in an embodiment of the present invention.

[0054] Figure 3 A schematic diagram of the structure of the EDFA-pumped laser lifetime prediction system based on dynamic stress accumulation provided in an embodiment of the present invention. Detailed Implementation

[0055] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. In addition, the technical features of the various embodiments or individual embodiments provided by the present invention can be arbitrarily combined to form new technical solutions. Such combinations are not bound by the order of steps and / or structural composition patterns, but must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0056] Please see Figure 1 This invention provides a method for predicting the lifetime of an EDFA-pumped laser based on dynamic stress accumulation, comprising:

[0057] Step 1: Real-time acquisition of the pump laser's drive current, forward voltage drop, backlight power, and case temperature during operation;

[0058] Step 2: Obtain the calibrated thermal resistance value of the current pump laser, and calculate the instantaneous junction temperature by combining the driving current, forward voltage drop, backlight power and case temperature;

[0059] Step 3: Collect the driving current and instantaneous junction temperature at fixed time intervals, and calculate the total damage rate under the current stress condition by combining the total damage rate model;

[0060] Step 4: Calculate the total cumulative damage in real time based on the total damage rate, and predict the lifetime based on the total cumulative damage calculated in real time.

[0061] Step 1 is used for dynamic stress sensing, which involves real-time acquisition of the driving current of the pump laser during its operating state using a high-precision sensor and acquisition circuit. Forward pressure drop With shell temperature These parameters together constitute the "dynamic stress" acting on the laser.

[0062] Specifically, the driving current of the pump laser : Data is collected by a high-precision, low-resistance resistor connected in series in the laser drive circuit;

[0063] Forward voltage drop of pump laser The voltage is acquired by a voltage divider circuit connected in parallel across the laser.

[0064] Case temperature of pump laser Acquired by a thermistor integrated inside the pump laser;

[0065] The collected parameters are converted into digital signals by the AD conversion module and then transmitted to the data processing unit for storage and subsequent analysis.

[0066] Step 2 is primarily used for junction temperature calculation. Prior to this, thermal resistance calibration is required, such as... Figure 2 As shown.

[0067] The degradation mechanism of semiconductor lasers is essentially a thermoelectrochemical reaction, the rate of which is related to the junction temperature. The relationship is exponential. Meanwhile, junction temperature is a true reflection of dynamic stress: junction temperature... It is driven by the current (Heat source) and system thermal resistance (Heat dissipation capacity) is a transient variable jointly determined by [variables]. Only by obtaining [the relevant information]... Only then can electrical stress and The thermal stress, together with the dynamic input, enables the life prediction model to respond to fluctuations in actual workload.

[0068] For semiconductor lasers, the traditional method for measuring junction temperature is the forward voltage drop method, which relies on the premise that the laser junction region has no self-heating effect, thus requiring the use of small pulse currents for measurement. However, the EDFA pump laser operating normally in a system always operates under a continuous high current state, resulting in significant self-heating in the junction region, with its temperature already far exceeding the case temperature. Forcing the use of the forward voltage drop method would introduce huge errors, making it theoretically unsuitable for online monitoring. Therefore, this invention proposes a junction temperature estimation method based on in-system thermal resistance calibration, thereby providing reliable key parameters for lifetime prediction models.

[0069] The thermal resistance calibration is as follows:

[0070] The thermal behavior of a laser PN junction can be described by the following thermal resistance equation:

[0071] ,

[0072] in, Junction temperature, which is the temperature of the core region of the PN junction of a laser (unit: Kelvin). The shell temperature is the temperature at a specified measurement point on the laser package shell (unit: Kelvin). Thermal resistance from junction to shell (unit: K / W, Kelvin per watt). Thermal power consumption, which is the total heat generated inside the laser, is measured in watts.

[0073] Furthermore, the heat dissipation is obtained by subtracting the output optical power from the input electrical power:

[0074] ,

[0075] in, This is the driving current of the laser. This represents the forward voltage drop of the laser. This refers to the forward output optical power.

[0076] To simplify the system structure and reduce hardware costs, this invention utilizes a backlight detection photodiode integrated within the pump laser. Based on the physical characteristics of the laser resonator, the backlight power... With forward output optical power There exists a stable proportional relationship (i.e., the ratio before and after). Let the ratio before and after be k, then we have:

[0077] ,

[0078] To obtain k, data can be collected at multiple output power points. and The data is then linearly fitted, thus achieving indirect monitoring of the output optical power without the need for an additional forward optical power acquisition module. Substituting (2) and (3) into equation (1), we get:

[0079] ,

[0080] In the junction temperature calculation model of equation (4), All of these can be reported by the corresponding acquisition circuits; the core bottleneck lies in thermal resistance. Although laser manufacturers will provide... While the obtained values ​​are typically broad and typical, they often fail to meet accuracy requirements. Traditional calibration methods place the laser in an ideal laboratory environment, which, while providing numerical values, disrupts the actual installation and heat dissipation conditions of the laser, fundamentally causing the calibration results to deviate from real-world operating conditions. This invention proposes a system-wide thermal resistance calibration method to ensure that the obtained values ​​are accurate. This accurately reflects the thermal behavior of the device in its final application environment. Also based on formula (4), given the other parameters, The calculation formula is as follows:

[0081] ,

[0082] In equation (5), except Apart from that, all other parameters can be reported by the corresponding acquisition circuit. This refers to the temperature of the core region of the PN junction in a laser. Because the PN junction is located inside a semiconductor chip and its size is extremely small (typically on the order of micrometers), it is difficult to measure directly. The junction temperature is usually inferred using the forward voltage drop method. As mentioned earlier, although the traditional forward voltage drop method cannot meet the needs of real-time monitoring, the physical principle of this method is precise, making it a reliable method for estimating thermal resistance. It is an ideal tool for performing one-time, high-precision calibration. The following details the in-system calibration method based on this principle.

[0083] The forward voltage drop method is based on the Shockley equation, which states that within a finite temperature range, under constant forward current (usually a small pulse current to avoid self-heating effects), the forward voltage drop... absolute temperature of the PN junction (Unit: K) shows an approximately linear relationship, therefore:

[0084] .

[0085] To achieve based on positive pressure drop The junction temperature calculation requires calibration of parameters a and b in formula (6). This invention abandons the traditional calibration scheme that relies on a temperature cycling chamber and proposes an in-system calibration strategy: directly utilizing the TEC temperature control circuit integrated into the EDFA module to accurately set and maintain multiple calibration point temperatures such as 0℃, 25℃, and 50℃. The EDFA operates in ACC mode, waiting... and TEC drive current After stabilization, apply a specific small pulse current (e.g., 10mA, 10μs, 1% duty cycle) to the laser, and quickly test and record a set of data. The values ​​are calculated by removing obviously abnormal measurements and then taking the arithmetic mean. Value. It should be noted here that conventional pump laser thermal resistance calibration is performed on the pump laser device alone. The method described in this invention is mainly for the pump laser in the EDFA. Therefore, "in system" means that the pump laser has been installed in the EDFA product. It is a calibration of the pump laser installed in the EDFA, not a calibration of the pump laser before it is installed.

[0086] Under the condition of applying a specific small pulse current, the laser junction region has no self-heating effect, therefore Therefore, equation (6) is approximately:

[0087] .

[0088] By changing the temperature settings and following the method described above, tests were conducted at different temperature points. and By performing linear fitting on the three sets of data, the values ​​of a and b corresponding to equation (6) are obtained. Therefore, under the same small pulse conditions, it is possible to... Inverse calculation This method eliminates the need for external temperature control equipment and integrates the calibration process into the system, which not only significantly reduces costs and operational complexity but also ensures the consistency between the calibration environment and the actual working environment of the laser, thereby improving the applicability and accuracy of the model.

[0089] Next, for Perform calibration. The EDFA is operating in AGC mode with the gain set to maximum. Adjust the input light to maximize the output. Wait for the housing temperature to reach maximum. and drive current Once everything is stable, begin the test. Under steady-state conditions, record the corresponding values. and Next, the laser driver was repeatedly switched to the same small pulse current as described above, and a set of tests were quickly tested and recorded. Value; after removing obviously abnormal measurements, the arithmetic mean is taken as the calculation value. Value. Put this... Substituting the value into formula (6), the junction temperature under this steady-state condition is obtained. Finally, Substituting into formula (5), the calibrated result is calculated. value.

[0090] The specific calculation of junction temperature is as follows:

[0091] After the system starts up, it first reads the thermal resistance value obtained from the individual calibration of the laser from the storage unit. During system operation, the data acquisition unit collects data. and Subsequently, the data processing unit performs the arithmetic and logical operations described in formula (4) to obtain the instantaneous junction temperature. .

[0092] Steps 3 and 4 are primarily used for dynamic damage accumulation and lifetime prediction. The lifetime of an EDFA essentially depends on the lifetime of its internal pump laser. Based on the laser's failure physics, its degradation rate is simultaneously influenced by thermal stress (dominated by junction temperature) and electrical stress (dominated by current). Here, a dynamic damage accumulation method based on the Arrhenius model and the inverse power-law model is proposed.

[0093] The Arrhenius model (thermal stress) is as follows:

[0094] ,

[0095] in, To achieve the junction temperature Characteristic lifetime (unit: hours); The junction temperature of the laser (unit: Kelvin). is a proportionality constant (related to laser model) (unit: hour); Ea is the activation energy of the failure mechanism (unit: eV); k is the Boltzmann constant, which is fixed. eV / K.

[0096] The inverse power-law model (electric stress) is as follows:

[0097] ,

[0098] In the current Characteristic lifetime (unit: hours); This represents the laser's drive current (unit: mA). is a proportionality constant (related to the laser model) (unit: hours); n is the current acceleration exponent, a dimensionless constant that characterizes the sensitivity of lifetime to current.

[0099] For model parameters Prioritize obtaining data from the pump laser manufacturer. If unavailable, at least two lifetime data points under different stress conditions can be found in the manufacturer's reliability report or datasheet. Back-calculation can be performed using (8) and (9). More precisely, an accelerated aging experiment matrix containing different temperatures and currents can be designed. By monitoring the degradation of laser parameters (optical power, threshold current, etc.), a graph showing the relationship between failure time and stress level can be plotted. Through curve fitting, the results can be directly obtained. .

[0100] Damage rate It is the reciprocal of lifespan. Here, there are two independent instantaneous damage rates:

[0101] Thermal damage rate:

[0102] ,

[0103] Its unit is 1 / hour, which means: at the current junction temperature Below, the life points consumed per hour.

[0104] Electrical damage rate:

[0105] ,

[0106] The unit is 1 / hour, meaning: at the current... Below, the life points consumed per hour.

[0107] Combining the two damage rates, we get the total damage rate. :

[0108] ,

[0109] Substituting the instantaneous damage rate model, we obtain:

[0110] ,

[0111] Dynamic damage accumulation specifically refers to:

[0112] Total cumulative damage It is the integral of the total damage rate over time:

[0113] ,

[0114] because and These are discrete sampled data. In actual calculations, this integral is completed through numerical integration.

[0115] During system operation, at fixed time intervals (e.g., 5 minutes) Collect drive current and junction temperature Substitute into formula (13) to calculate the total damage rate under the current stress condition. Each time the total damage rate is calculated, a damage accumulation is performed, resulting in:

[0116] ,

[0117] The initial value is 0.

[0118] Real-time calculation during system operation Define the laser's health state as SOH and remaining lifetime as RUL, then:

[0119] ,

[0120] in, This represents the initial lifetime of the laser.

[0121] Based on the same inventive concept as the aforementioned method embodiments, this invention also provides an EDFA-pumped laser lifetime prediction system based on dynamic stress accumulation, such as... Figure 3 As shown, it includes:

[0122] The dynamic stress sensing unit is used to collect drive current, forward voltage drop, back light power and case temperature in real time;

[0123] The data processing unit is used to calculate the instantaneous junction temperature based on the calibrated thermal resistance of the current pump laser, combined with the driving current, forward voltage drop, backlight power and case temperature; to collect the driving current and instantaneous junction temperature at fixed time intervals, and to calculate the total damage rate under the current stress condition by combining the total damage rate model; and to calculate the total cumulative damage in real time based on the total damage rate, and to predict the lifetime based on the total cumulative damage calculated in real time.

[0124] Optionally, the system further includes a thermal resistance calibration unit for:

[0125] The relationship between forward voltage drop and junction temperature is constructed based on the forward voltage drop method, and the parameters in the relationship are calibrated using an in-system calibration strategy to obtain the calibrated relationship.

[0126] Under steady-state conditions of the pump laser, the driving current, forward voltage drop, backlight power, and case temperature were recorded.

[0127] The pump laser driver is repeatedly switched to the small pulse current applied during system calibration, a set of forward voltage drops is tested and recorded, and the average of this set of forward voltage drops is used to obtain the forward voltage drop for calculation.

[0128] Substituting the forward voltage drop used in the calculation into the calibrated relationship, the junction temperature under the current steady-state conditions is obtained;

[0129] The junction temperature under the current steady-state conditions, along with the recorded drive current, forward voltage drop, back light power, and case temperature, are substituted into the thermal resistance calculation expression to obtain the calibrated thermal resistance value.

[0130] Optionally, the system further includes a storage unit for:

[0131] Store calibrated thermal resistance values, model parameters, and historical damage data.

[0132] In summary, the present invention addresses the problem that existing technologies cannot accurately reflect the impact of dynamic operating conditions on lifespan. It provides a technical solution that can track the dynamic working stress of a laser in real time and make accurate lifespan predictions accordingly. By collecting the electrical and thermal parameters of the laser in real time, its instantaneous junction temperature is accurately calculated, and the dynamically changing current and junction temperature are applied together to the physical lifespan model. Through the linear cumulative damage law, its health status and remaining lifespan are updated in real time.

[0133] The terms “comprising” and “having”, and any variations thereof, in the specification, claims, and accompanying drawings of this invention are intended to cover a non-exclusive inclusion, such as a process, method, system, product, or apparatus that includes a series of steps or units, not necessarily limited to those explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0134] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the technical solutions of the embodiments of the present invention.

Claims

1. A method for predicting the lifetime of an EDFA pump laser based on dynamic stress accumulation, characterized in that, The method comprises the following steps: Real-time acquisition of driving current, forward voltage drop, back light power and shell temperature of the pump laser under working state; Obtaining the calibrated thermal resistance value of the current pump laser, combining the driving current, forward voltage drop, back light power and shell temperature, and calculating the instantaneous junction temperature; Collecting the driving current and instantaneous junction temperature at fixed time intervals, combining the total damage rate model, and calculating the total damage rate under the current stress condition; Real-time calculation of total cumulative damage based on the total damage rate, and life prediction based on the real-time calculation of total cumulative damage.

2. The method for predicting the lifetime of EDFA pump laser based on dynamic stress accumulation according to claim 1, characterized in that, The calibration of the thermal resistance value of the current pump laser comprises the following steps: Based on the forward voltage drop method, a relationship between the forward voltage drop and the junction temperature is constructed, and the parameters in the relationship are calibrated by using the in-system calibration strategy to obtain the calibrated relationship; Under the steady-state condition of the pump laser, the driving current, forward voltage drop, back light power and shell temperature are recorded; The pump laser driving is repeatedly switched to the small pulse current applied in the system calibration, a group of forward voltage drops are tested and recorded, and the calculated forward voltage drop is obtained by averaging the group of forward voltage drops; The calculated forward voltage drop is substituted into the calibrated relationship to obtain the junction temperature under the current steady-state condition; The junction temperature under the current steady-state condition is substituted into the calculation expression of the thermal resistance value together with the recorded driving current, forward voltage drop, back light power and shell temperature to calculate the calibrated thermal resistance value.

3. The method for predicting the lifetime of EDFA pump laser based on dynamic stress accumulation according to claim 2, characterized in that, The calculation expression of the thermal resistance value is: ， wherein, is the junction temperature, is the case temperature, is the drive current, is the forward voltage drop, is the front-to-back ratio, is the back light power.

4. The method for predicting the lifetime of EDFA pump laser based on dynamic stress accumulation according to claim 3, characterized in that, When calibrating the thermal resistance value of the current pump laser, the following pre-post ratio calibration is further included: Establishing a proportional relationship between back light power and forward output light power is: ; Acquisition at multiple output power points And Data, and linear fitting to determine the ratio .

5. The method for predicting the lifetime of EDFA pump laser based on dynamic stress accumulation according to claim 2, characterized in that, The in-system calibration strategy is: A plurality of calibration point temperatures are set by using the TEC temperature control circuit integrated in the EDFA module itself; The EDFA works in the ACC mode, and after the shell temperature and the TEC driving current are stable, a small pulse current is applied to the pump laser, and under the condition of the applied small pulse current, the shell temperature is approximately equal to the junction temperature, and the relationship between the forward voltage drop and the junction temperature is converted into the relationship between the forward voltage drop and the shell temperature; The forward voltage drop and the shell temperature under different calibration point temperatures are respectively tested and recorded; According to the recorded forward voltage drops and shell temperatures at different calibration point temperatures, the parameters of the relationship between the forward voltage drop and the shell temperature are obtained by linear fitting, and then the parameters of the relationship between the forward voltage drop and the junction temperature are obtained.

6. The method for predicting the lifetime of EDFA pump laser based on dynamic stress accumulation according to claim 1, wherein, The total damage rate model is: ， wherein, are proportional constants, is an activation energy of the failure mechanism, is the junction temperature at time t, is the pump laser drive current at time t, is the current acceleration exponent.

7. The method for predicting the lifetime of EDFA pump laser based on dynamic stress accumulation according to claim 6, characterized in that, Real-time calculation of total cumulative damage based on the total damage rate, and life prediction based on the real-time calculation of total cumulative damage, comprises: Each time the total damage rate is calculated, damage is accumulated, and the variable that is accumulated each time is wherein is the total damage rate, is the fixed time interval; Real-time calculation of total cumulative damage and, in turn, lifetime prediction wherein, is the initial lifetime of the pump laser.

8. A system for predicting the lifetime of an EDFA pump laser based on dynamic stress accumulation, characterized in that, It comprises: A dynamic stress sensing unit for real-time acquisition of driving current, forward voltage drop, back light power and shell temperature; A data processing unit for calculating the instantaneous junction temperature according to the calibrated thermal resistance value of the current pump laser, combining the driving current, forward voltage drop, back light power and shell temperature; Collecting the driving current and instantaneous junction temperature at fixed time intervals, combining the total damage rate model, and calculating the total damage rate under the current stress condition; And, based on the total damage rate, real-time calculation of total cumulative damage, and life prediction based on the real-time calculation of total cumulative damage.

9. The EDFA pump laser lifetime prediction system based on dynamic stress accumulation of claim 8, wherein, The system further comprises a thermal resistance calibration unit for: Based on the forward voltage drop method, a relationship between the forward voltage drop and the junction temperature is constructed, and the parameters in the relationship are calibrated by using the in-system calibration strategy to obtain the calibrated relationship; Under the steady state condition of the pump laser, record the driving current, forward voltage drop, back light power and shell temperature; Switch the driving of the pump laser to the small pulse current applied in the system calibration for multiple times, test and record a group of forward voltage drops, and obtain the calculated forward voltage drop according to the average of the group of forward voltage drops; Substitute the calculated forward voltage drop into the calibrated relational expression to obtain the junction temperature under the current steady state condition; Substitute the junction temperature under the current steady state condition, the recorded driving current, forward voltage drop, back light power and shell temperature into the calculation expression of the thermal resistance value to obtain the calibrated thermal resistance value.

10. The EDFA pump laser lifetime prediction system based on dynamic stress accumulation of claim 8, wherein, The system further comprises a storage unit, configured to: store the calibrated thermal resistance value, model parameters and historical damage data.

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