Temperature regulation and control device and method for semiconductor laser

Abstract

The invention relates to the technical field of semiconductor lasers, in particular to a temperature regulation and control device and method for a semiconductor laser, and the method comprises the steps: obtaining different types of monitoring curves, and analyzing the complex change characteristics of operation temperature and operation power according to the monitoring curves, so as to determine a heat accumulation effect index; determining the degree of efficiency loss caused by the heat accumulation effect by analyzing the correlation among the operation temperature change, the operation power change and the threshold current change and combining the heat accumulation effect index; then determining a temperature regulation and control demand coefficient by analyzing the temperature feedback control precision condition and the thermal dynamic characteristic of the semiconductor laser and combining the efficiency loss degree; and finally, a default proportional gain value in the PID control module is adjusted by using the temperature regulation and control demand coefficient to obtain an adjusted proportional gain value so as to carry out temperature regulation and control on the semiconductor laser, which is beneficial for the temperature regulation and control device to respond to the change of the working environment of the laser in time.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor lasers, and in particular to a temperature control device and method for semiconductor lasers. Background Art

[0002] Semiconductor lasers, due to their small size, high efficiency, and fast response speed, are widely used in communications, optical storage, laser printing, laser displays, medical diagnostics, and other fields. With the rapid development of optoelectronics technology, the performance requirements for semiconductor lasers are constantly increasing, especially in terms of power, wavelength stability, and beam quality. Temperature is one of the most important factors affecting semiconductor laser performance, and its changes directly affect the laser's output power, wavelength, frequency, and other characteristics.

[0003] Currently, a variety of temperature control devices and methods have been proposed for semiconductor lasers, including hotspot coolers, water cooling systems, temperature sensors, and feedback control. Although existing temperature control devices and methods have solved the temperature problem of semiconductor lasers to a certain extent, they still have shortcomings.

[0004] Existing temperature control methods have a relatively slow response speed when faced with rapidly changing operating conditions, making it difficult for the system to adjust the temperature to the set value in a short period of time, which in turn affects the instantaneous performance of the laser and the stability of the light output. In addition, when the laser undergoes a start-stop process or encounters sudden environmental changes, the temperature control device may lag, causing a transient wavelength shift, seriously affecting the overall performance and communication quality of the system. Summary of the Invention

[0005] In order to solve the technical problem of low response speed of the temperature control of the existing semiconductor laser, the present invention aims to provide a temperature control device and method for a semiconductor laser. The technical solution adopted is as follows: An embodiment of the present invention provides a temperature control method for a semiconductor laser, the method comprising the following steps: Obtaining an operating temperature monitoring curve, an operating power monitoring curve, a threshold current monitoring curve, an output wavelength monitoring curve, and an operating frequency monitoring curve of the semiconductor laser during the current monitoring period; Analyze the complex change characteristics of operating temperature and operating power during laser operation based on the operating temperature monitoring curve and operating power monitoring curve, and determine the heat accumulation effect index in the semiconductor laser; According to the operating temperature monitoring curve, operating power monitoring curve and threshold current monitoring curve, the correlation between the operating temperature change and the operating power change and threshold current change during the operation of the laser is analyzed. Combined with the heat accumulation effect index, the efficiency loss degree of the semiconductor laser caused by the heat accumulation effect is determined; Analyze the temperature feedback control accuracy and thermal dynamic characteristics of the semiconductor laser based on the operating power monitoring curve, output wavelength monitoring curve, and operating frequency monitoring curve, and determine the temperature control requirement coefficient of the semiconductor laser in combination with the degree of efficiency loss; The temperature control requirement coefficient is used to adjust the default proportional gain value in the PID control module to obtain the adjusted proportional gain value for temperature control of the semiconductor laser.

[0006] Furthermore, determining the heat accumulation effect index in the semiconductor laser includes: Analyze the chaotic, frequent, and continuously rising operating temperature changes during the current monitoring period based on the operating temperature monitoring curve to determine the complexity of temperature changes during the operation of the semiconductor laser; Determine the complexity of power variation during the operation of the semiconductor laser based on the operating power monitoring curve; The temperature variation complexity and power variation complexity during the operation of the semiconductor laser are integrated to determine the heat accumulation effect index in the semiconductor laser; wherein, the temperature variation complexity and power variation complexity are both proportional to the heat accumulation effect index.

[0007] Furthermore, determining the complexity of temperature changes during operation of the semiconductor laser includes: Calculate the first difference value between every two operating temperatures according to the operating temperature monitoring curve, and determine the average value of all the first difference values ​​as the degree of temperature change disorder; Calculating the time interval between each two adjacent extreme value points based on the operating temperature monitoring curve, and determining the frequency of temperature changes based on each time interval value; wherein the time interval value is inversely proportional to the frequency of temperature changes; Calculating a second difference between the operating temperature at a subsequent monitoring moment and the operating temperature at a previous monitoring moment according to the operating temperature monitoring curve, and determining an average value of all the second difference values ​​as the degree of continuous temperature increase; The complexity of temperature changes during the operation of the semiconductor laser is determined by integrating the degree of disorder of temperature changes, the frequency of temperature changes and the degree of continuous temperature increase; among them, the degree of disorder of temperature changes, the frequency of temperature changes and the degree of continuous temperature increase are all proportional to the complexity of temperature changes.

[0008] Furthermore, determining the degree of efficiency loss of the semiconductor laser caused by the heat accumulation effect includes: Determine the slope values ​​corresponding to every two adjacent data points in the operating temperature monitoring curve, the operating power monitoring curve, and the threshold current monitoring curve, and select each positive temperature slope value from each slope value corresponding to the operating temperature monitoring curve; Recording each monitoring sub-period of a positive temperature slope value as a target sub-period, and filtering out the power slope value and current slope value of each target sub-period from the slope values ​​corresponding to the operating power monitoring curve and the threshold current monitoring curve; The efficiency loss degree is determined according to the difference between the positive temperature slope value and the power slope value, the difference between the positive temperature slope value and the current slope value, and the heat accumulation effect indicator in the same target sub-period.

[0009] Furthermore, determining the degree of efficiency loss based on the difference between the positive temperature slope value and the power slope value, the difference between the positive temperature slope value and the current slope value, and the heat accumulation effect indicator in the same target sub-period includes: Determining an evaluation value of the inhibitory effect of the heat accumulation effect on the operating power of the semiconductor laser based on a third difference between the positive temperature slope value and the power slope value in the same target sub-period and in combination with the heat accumulation effect index; wherein the third difference and the heat accumulation effect index are both proportional to the inhibitory effect evaluation value; Based on a fourth difference value between the positive temperature slope value and the current slope value in the same target sub-period, combined with the inhibition effect evaluation value, the degree of efficiency loss of the semiconductor laser caused by the heat accumulation effect is determined; wherein the fourth difference value and the inhibition effect evaluation value are both proportional to the degree of efficiency loss.

[0010] Furthermore, determining the temperature control requirement coefficient of the semiconductor laser includes: Determine the degree of power fluctuation based on the operating power monitoring curve, and determine the degree of wavelength variation based on the output wavelength monitoring curve; Determining the temperature feedback control accuracy of the semiconductor laser based on the degree of power fluctuation, the degree of wavelength variation, and the degree of efficiency loss; wherein the degree of power fluctuation, the degree of wavelength variation, and the degree of efficiency loss are all inversely proportional to the temperature feedback control accuracy; The operating state index of the semiconductor laser is determined according to the operating frequency monitoring curve, and the temperature control requirement coefficient is determined in combination with the temperature feedback control accuracy.

[0011] Furthermore, determining the power fluctuation degree according to the operating power monitoring curve and determining the wavelength variation degree according to the output wavelength monitoring curve includes: Determine a maximum power value and a minimum power value according to the operating power monitoring curve, and use the difference between the maximum power value and the minimum power value as the power fluctuation degree; The output wavelength difference between every two adjacent monitoring moments is determined according to the output wavelength monitoring curve, and the average value of all the output wavelength differences is used as the wavelength change degree.

[0012] Furthermore, determining the operating state index of the semiconductor laser according to the operating frequency monitoring curve and determining the temperature control requirement coefficient in combination with the temperature feedback control accuracy includes: Determining a normalized value of the negative correlation of the temperature feedback control accuracy and determining a normalized value of the operating state indicator; The two normalized values ​​are combined to determine the temperature control requirement coefficient of the semiconductor laser; wherein both the normalized values ​​are proportional to the temperature control requirement coefficient.

[0013] Furthermore, the temperature control demand coefficient is used to adjust the default proportional gain value in the PID control module to obtain the adjusted proportional gain value, including: The temperature control demand coefficient is multiplied by the default proportional gain value in the PID control module, and the product is used as the adjusted proportional gain value.

[0014] Another embodiment of the present invention provides a temperature control device for a semiconductor laser, comprising a processor and a memory, wherein the processor is configured to process instructions stored in the memory to implement a temperature control method for a semiconductor laser.

[0015] The present invention has the following beneficial effects: The existing temperature control system for semiconductor lasers has a slow response speed, making it difficult to adjust to the set temperature in a short period of time, which affects the instantaneous performance of the laser. In order to improve the response speed of temperature control, the environmental parameter characteristics of the semiconductor laser during the current monitoring period are analyzed. Based on the characteristics of different types of environmental parameters, the heat accumulation effect index is first determined. Then, the degree of efficiency loss of the semiconductor laser caused by the heat accumulation effect is determined. Then, the temperature control demand of the semiconductor laser is quantified. The adjusted proportional gain value determined by the temperature control demand coefficient is used to effectively control the temperature of the semiconductor laser. The present invention enables the temperature control device to respond to changes in the working environment of the semiconductor laser in a timely manner, ensuring temperature fluctuations and the stability and output consistency of the laser performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions and advantages of the embodiments of the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 A flow chart of a temperature control method for a semiconductor laser according to an embodiment of the present invention; Figure 2Flowchart for implementing step S2 in an embodiment of the present invention; Figure 3 Flowchart for implementing step S3 in an embodiment of the present invention; Figure 4 This is a flowchart for implementing step S4 in an embodiment of the present invention. DETAILED DESCRIPTION

[0018] To further illustrate the technical means and effects employed by the present invention to achieve its intended objectives, the following, in conjunction with the accompanying drawings and preferred embodiments, describes in detail the specific implementations, structures, features, and effects of the technical solutions proposed by the present invention. In the following description, references to "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics of one or more embodiments may be combined in any suitable manner.

[0019] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0020] The application scenarios targeted by the present invention may be: In fiber-optic communication systems, semiconductor lasers serve as signal sources, converting electrical signals into optical signals. With the increasing demand for data transmission, optical communication technology is developing toward higher transmission rates and longer transmission distances. High-power semiconductor lasers can maintain signal strength and quality over long optical fibers, supporting high-speed internet, connections between data centers, and large-scale cloud computing services. Temperature control devices are particularly important in this process, ensuring the wavelength stability and power output of the laser, thereby reducing signal distortion and attenuation and improving communication quality. Existing temperature control devices and methods have solved the temperature problem of semiconductor lasers to a certain extent, but there are still shortcomings.

[0021] In order to overcome the above-mentioned shortcomings of semiconductor laser temperature control, an embodiment of the present invention provides a temperature control method for a semiconductor laser, such as Figure 1 As shown, the following steps are included: S1, obtaining an operating temperature monitoring curve, an operating power monitoring curve, a threshold current monitoring curve, an output wavelength monitoring curve, and an operating frequency monitoring curve of a semiconductor laser in a current monitoring period.

[0022] Before performing temperature control on a semiconductor laser, it is first necessary to obtain analytical data related to temperature control, namely, the environmental parameters during the operation of the semiconductor laser, such as the temperature, output power, threshold current, output wavelength, and operating frequency during the operation of the semiconductor laser. Among them, the data collection period and collection interval of all categories of analytical data are consistent. The current monitoring period can be set to 20 minutes, and the collection interval can be set to 10 seconds. The implementer can set the current monitoring period and collection interval according to the specific actual situation, without specific restrictions.

[0023] For the operating temperature monitoring curve, the horizontal axis is the monitoring time, and the vertical axis is the operating temperature. Select a suitable temperature sensor. Common options include thermocouples, thermistors, and infrared temperature sensors. Install the selected temperature sensor at a key location on the semiconductor laser, usually on the laser's base or heat sink. This accurately reflects the laser's operating temperature and ensures good contact between the sensor and the laser surface to improve data accuracy and real-time performance. Collect the operating temperature of the semiconductor laser at each moment during the current monitoring period and perform curve fitting on the operating temperature sequence corresponding to the current monitoring period to obtain the operating temperature monitoring curve.

[0024] For the operating power monitoring curve, the horizontal axis is the monitoring time, and the vertical axis is the operating power. Select a suitable power monitoring device, such as a photodiode detector or a pyroelectric power meter. Install the selected power monitoring device at a key location on the semiconductor laser, usually behind the laser output window or on the back of the laser chip. This can avoid affecting the performance of the main optical path and ensure that the response speed matches the control requirements. Collect the operating power of the semiconductor laser at each moment during the current monitoring period, and perform curve fitting on the operating power sequence corresponding to the current monitoring period to obtain the operating power monitoring curve.

[0025] For the threshold current monitoring curve, the horizontal axis is monitoring time, and the vertical axis is threshold current. The threshold current is the minimum current required for the laser to begin emitting light, which needs to be measured through the current-optical power characteristic curve. Select a suitable current acquisition device, commonly a high-precision current probe. Install the selected current acquisition device at a key position on the semiconductor laser, usually between the output of the laser driver power supply and the laser positive pole or in the current feedback loop of the driver IC. It can be as close to the laser positive pole as possible to ensure that the current and optical power are strictly synchronized and the current inflection point is accurately captured. Collect the threshold current of the semiconductor laser at each moment during the current monitoring period, and perform curve fitting on the threshold current sequence corresponding to the current monitoring period to obtain the threshold current monitoring curve.

[0026] For the output wavelength monitoring curve, the horizontal axis is the monitoring time, and the vertical axis is the output wavelength. Select a suitable wavelength acquisition device, such as a spectrum analyzer or fiber Bragg grating wavelength meter. Install the selected wavelength acquisition device in a key location, typically on the back of the laser chip or by inserting a spectrometer into the main optical path to prevent beam quality degradation. Collect the output wavelength of the semiconductor laser at each moment during the current monitoring period, and perform curve fitting on the output wavelength sequence corresponding to the current monitoring period to obtain the output wavelength monitoring curve.

[0027] The operating frequency monitoring curve has the monitoring time as the horizontal axis and the operating frequency as the vertical axis. The operating frequency refers to the operating frequency of the semiconductor laser during the monitoring period. A frequency meter is used to measure the operating frequency of the semiconductor laser in real time during the monitoring period, obtaining the operating frequency at each moment. A curve fitting is then performed on the operating frequency sequence corresponding to the current monitoring period to obtain the operating frequency monitoring curve.

[0028] When collecting analytical data related to temperature control, a data acquisition system can be configured to convert the sensor's analog signal into a digital signal, and then ensure that the analytical data can be transmitted to the monitoring system through a serial port, USB, or Ethernet. After obtaining the data, the monitoring system conducts further analysis and effectively adjusts the temperature control device (such as the hot spot cooler) in the semiconductor laser based on the feedback of the analytical data, ensuring that the laser operates in an ideal state, thereby improving the performance and stability of the entire optical communication system.

[0029] It should be noted that in the embodiments of the present invention, in order to facilitate subsequent processing of data and avoid differences in units and numerical magnitudes between data, different categories of data are standardized during the data collection process to eliminate the influence of dimensions in data calculations.

[0030] S2, analyzing the complex change characteristics of the operating temperature and operating power during the operation of the laser according to the operating temperature monitoring curve and the operating power monitoring curve, and determining the heat accumulation effect index in the semiconductor laser.

[0031] Here, the heat accumulation effect index refers to the heat accumulation effect during the operation of the semiconductor laser. The larger the heat accumulation effect index is, the more obvious the heat accumulation characteristics of the semiconductor laser are during the current monitoring period, which is specifically manifested in the complex change characteristics of the operating temperature and operating power.

[0032] By analyzing the heat accumulation effect during laser operation, it is possible to identify the temperature change trend of the laser under continuous operation. By understanding the heat distribution and accumulation under different operating conditions, the parameters of the temperature control device can be optimized to ensure effective heat dissipation and improve the overall heat dissipation efficiency of the system.

[0033] As an exemplary embodiment, the above step S2 can be performed by Figure 2 The steps S21 to S23 shown implement: S21, analyzing the disorder, frequency, and continuous increase of operating temperature changes during the current monitoring period according to the operating temperature monitoring curve, and determining the complexity of temperature changes during the operation of the semiconductor laser.

[0034] Preferably, the above step S21 can be implemented by the following steps: In the first step, a first difference value between every two operating temperatures is calculated according to the operating temperature monitoring curve, and an average value of all first difference values ​​is determined as the temperature variation disorder degree.

[0035] As an example, the calculation formula for the degree of temperature variation disorder can be: Where, Indicates the degree of temperature change disorder during the current monitoring period. Indicates the operating temperature at the e-th moment in the current monitoring period, Indicates the operating temperature at the vth moment in the current monitoring period, represents the first difference between the operating temperatures at the e-th moment and the v-th moment in the current monitoring period, Indicates the average value of all first difference values ​​in the current monitoring period.

[0036] In the calculation formula of the degree of temperature variation disorder, the greater the difference between every two operating temperatures in the current monitoring period, the more disordered the operating temperature variation in the current monitoring period is, and the lower the regularity of the temperature variation is.

[0037] In the second step, the time interval between each two adjacent extreme points is calculated according to the operating temperature monitoring curve, and the frequency of temperature changes is determined based on each time interval value.

[0038] The time interval value is inversely proportional to the frequency of temperature changes.

[0039] As an example, the calculation formula for the frequency of temperature changes can be: Where, Indicates the frequency of temperature changes during the current monitoring period, N indicates the number of time interval values, Indicates the cth time interval value in the current monitoring period.

[0040] In the calculation formula for the frequency of temperature changes, the smaller the time interval between the maximum point and the minimum point, the more frequent the operating temperature changes, that is, the operating temperature of the laser changes frequently during the current monitoring period.

[0041] In the third step, a second difference value between the operating temperature at the next monitoring moment and the previous monitoring moment is calculated according to the operating temperature monitoring curve, and an average value of all the second difference values ​​is determined as the degree of continuous temperature increase.

[0042] As an example, the calculation formula for the degree of continuous temperature increase can be: Where, Indicates the degree of continuous temperature increase in the current monitoring period, m indicates the number of operating temperatures in the current monitoring period, that is, the number of moments in the current monitoring period. Indicates the operating temperature at the i+1th moment in the current monitoring period, Indicates the operating temperature at the i-th moment in the current monitoring period, Indicates the second difference value between the operating temperatures at the i+1th moment and the ith moment in the current monitoring period.

[0043] In the calculation formula of the degree of continuous temperature rise, The larger the value is, the more the operating temperature of the laser in the current monitoring period shows a trend of continuous increase, and the greater the degree of continuous temperature increase.

[0044] The fourth step is to integrate the degree of disorder of temperature changes, the frequency of temperature changes and the degree of continuous temperature increase to determine the complexity of temperature changes during the operation of the semiconductor laser.

[0045] Here, the disorder of temperature changes, the frequency of temperature changes and the degree of continuous temperature increase are all proportional to the complexity of temperature changes.

[0046] As an example, the degree of disorder of temperature change, the frequency of temperature change and the degree of continuous temperature increase related to the complex temperature change are integrated and analyzed, such as calculating the product of each dimensionless degree value, that is, the product of the degree of disorder of temperature change, the frequency of temperature change and the degree of continuous temperature increase is used as the complexity of temperature change during the operation of the semiconductor laser.

[0047] Among them, the greater the degree of disorder and frequency of temperature changes, the higher the complexity of the temperature transient of the semiconductor laser during operation, that is, the greater the possibility of heat accumulation effect.

[0048] S22, determining the complexity of power variation during operation of the semiconductor laser according to the operating power monitoring curve.

[0049] In this embodiment, the complexity of the power variation may represent the complexity of the working environment of the semiconductor laser.

[0050] As an example, the amplitudes of the operating power monitoring data during the operation of the semiconductor laser are recorded as a type of amplitude; thus, the information entropy of the operating power is calculated based on the various operating powers in the operating power monitoring curve, and the information entropy is used as the complexity of the power change.

[0051] The calculation process of information entropy is a prior art and is not within the scope of protection of the present invention, and will not be elaborated on here.

[0052] S23, integrating the complexity of temperature variation and the complexity of power variation during the operation of the semiconductor laser, to determine the heat accumulation effect index in the semiconductor laser.

[0053] Here, the complexity of temperature change and the complexity of power change are both proportional to the heat accumulation effect index.

[0054] As an example, the dimensionless degree values ​​are fused, that is, the product of the temperature variation complexity and the power variation complexity is calculated as an indicator of the heat accumulation effect in the conductor laser.

[0055] As an example, the calculation formula for the heat accumulation effect index can be: Where, Indicates the heat accumulation effect index in semiconductor lasers, Indicates the degree of temperature change disorder during the current monitoring period. Indicates the frequency of temperature changes during the current monitoring period. Indicates the degree of continuous temperature increase during the current monitoring period. Indicates the complexity of temperature transient during the operation of semiconductor lasers. It indicates the complexity of temperature change during the operation of semiconductor laser, and H indicates the complexity of power change during the operation of semiconductor laser.

[0056] In the calculation formula of the heat accumulation effect index, when the continuous working environment is relatively complex, the temperature shows a continuous upward trend and the temperature has a high transient complexity, which means that the heat accumulation effect in the working process is stronger, that is, the heat accumulation effect index is larger.

[0057] The above analysis of the thermal accumulation effect in the operation of semiconductor lasers shows that the existence of the thermal accumulation effect, especially under high power and long-term working conditions, may cause the temperature of the laser to rise significantly, thereby affecting its performance and stability; as the temperature rises, changes in the carrier concentration, excited state and non-radiative recombination process inside the laser will directly affect the output characteristics of the laser.

[0058] S3. Analyze the correlation between the operating temperature change and the operating power change and threshold current change during the operation of the laser according to the operating temperature monitoring curve, the operating power monitoring curve and the threshold current monitoring curve. Combined with the heat accumulation effect index, determine the efficiency loss degree of the semiconductor laser caused by the heat accumulation effect.

[0059] Here, the degree of efficiency loss indicates the degree of influence of the heat accumulation effect on the working efficiency of the laser. The greater the degree of efficiency loss, the greater the influence of the heat accumulation effect of the laser on the working efficiency.

[0060] By analyzing the impact of thermal accumulation on lasers, the relationship between operating temperature and output power can be clarified, allowing for the design of more precise temperature control mechanisms to achieve optimal efficiency. Furthermore, by reducing the impact of high temperatures during laser operation, material aging and thermal damage can be reduced, thereby extending the life of the laser.

[0061] As an exemplary embodiment, the above step S3 can be performed by Figure 3 The steps S31 to S33 shown implement: S31 , determining the slope values ​​corresponding to every two adjacent data points in the operating temperature monitoring curve, the operating power monitoring curve, and the threshold current monitoring curve, and screening out positive temperature slope values ​​from the slope values ​​corresponding to the operating temperature monitoring curve.

[0062] Here, a positive temperature slope value refers to a positive slope value. When the slope value is a positive number, it indicates that the two data points corresponding to the slope value present an upward trend.

[0063] In this embodiment, for the operating temperature monitoring curve, the operating power monitoring curve and the threshold current monitoring curve, the slope formed by every two data points on the same monitoring curve is determined; for ease of distinction, the slope value corresponding to the operating temperature monitoring curve is recorded as the temperature slope value, the slope value corresponding to the operating power monitoring curve is recorded as the power slope value, and the slope value corresponding to the threshold current monitoring curve is recorded as the current slope value.

[0064] S32 , recording each monitoring sub-period of a positive temperature slope value as a target sub-period, and filtering out the power slope value and current slope value of each target sub-period from each slope value corresponding to the operating power monitoring curve and the threshold current monitoring curve.

[0065] Here, the monitoring sub-period refers to the time interval between two corresponding data points when determining the slope.

[0066] In this embodiment, in order to analyze the correlation between operating temperature changes and operating power changes, as well as the correlation between operating temperature changes and threshold current changes, it is necessary to mark the monitoring sub-periods of each positive temperature slope value, and filter out the time period that is the same as the monitoring sub-period marked with the positive temperature slope value from the operating power monitoring curve and the threshold current monitoring curve, and subsequently perform correlation analysis based on this.

[0067] S33 , determining the degree of efficiency loss according to the difference between the positive temperature slope value and the power slope value, the difference between the positive temperature slope value and the current slope value, and the heat accumulation effect index in the same target sub-period.

[0068] Preferably, the above step S33 can be implemented by the following steps: In the first step, based on the third difference between the positive temperature slope value and the power slope value in the same target sub-period and combined with the heat accumulation effect index, an evaluation value of the suppression effect of the heat accumulation effect on the operating power of the semiconductor laser is determined.

[0069] Among them, the third difference value and heat accumulation effect index are both proportional to the inhibition effect evaluation value.

[0070] As an example, the calculation formula for the inhibitory effect evaluation value can be: Where, Indicates the evaluation value of the inhibitory effect of heat accumulation on the operating power of semiconductor lasers, represents the positive temperature slope value of the sth target sub-period, represents the power slope value of the sth target sub-period, represents the absolute value function, represents the third difference between the positive temperature slope value and the power slope value of the s-th target sub-period, represents the average of all third difference values, An indicator of the heat accumulation effect in semiconductor lasers.

[0071] In the calculation formula of the inhibitory effect evaluation value, Indicates the difference between the positive temperature slope value and the power slope value at the same time interval. The larger the value, the more likely the output power will decrease when the temperature of the semiconductor laser increases. The heat accumulation effect usually leads to the attenuation of the output power, especially under high temperature conditions. The larger the value is, the higher the inhibitory effect of the thermal accumulation effect on the output power of the semiconductor laser is, and the greater the inhibitory effect evaluation value is.

[0072] It should be noted that while heat accumulation does affect the output power of semiconductor lasers, using it directly as a measure of operating efficiency is not entirely accurate. Output power is only one aspect of laser performance, and laser operating efficiency generally also considers multiple factors, such as input power and photoelectric conversion efficiency. Therefore, further analysis is needed to determine the difference between the temperature slope and current slope values.

[0073] In the second step, the efficiency loss degree of the semiconductor laser caused by the heat accumulation effect is determined based on the fourth difference value between the positive temperature slope value and the current slope value in the same target sub-period and the suppression effect evaluation value.

[0074] Among them, the fourth difference value and the inhibition effect evaluation value are both proportional to the degree of efficiency loss.

[0075] Heat accumulation leads to an increase in non-radiative recombination processes, which requires a higher current to reach the threshold of the laser. Therefore, if a clear upward trend is found in the threshold current at different temperatures, it may indicate that the heat accumulation effect is affecting the efficiency of the laser.

[0076] As an example, the calculation formula for the degree of efficiency loss of a semiconductor laser caused by the heat accumulation effect can be: Where, Indicates the degree of efficiency loss of semiconductor lasers caused by heat accumulation effects. Indicates the evaluation value of the inhibitory effect of heat accumulation on the operating power of semiconductor lasers, represents the positive temperature slope value of the sth target sub-period, represents the current slope value of the sth target sub-period, represents the fourth difference between the positive temperature slope value and the current slope value of the s-th target sub-period, represents the average of all fourth difference values.

[0077] In the calculation formula of efficiency loss degree, The larger the value, the weaker the linear relationship between the threshold current and operating temperature of the semiconductor laser during the current monitoring period. Under normal circumstances, as the laser operating temperature increases, the threshold current should increase, and the threshold current and operating temperature show a linear relationship. However, if the threshold current is abnormally increased within a certain temperature range, it may be due to heat accumulation, which will further increase the efficiency loss of the semiconductor laser. The larger the value is, the higher the efficiency loss of the semiconductor laser caused by the heat accumulation effect in the current monitoring period is, that is, the working efficiency of the semiconductor laser is lower.

[0078] Thus far, this embodiment has determined the degree of efficiency loss of the semiconductor laser caused by the heat accumulation effect.

[0079] S4. Analyze the temperature feedback control accuracy and thermal dynamic characteristics of the semiconductor laser based on the operating power monitoring curve, the output wavelength monitoring curve, and the operating frequency monitoring curve, and determine the temperature control requirement coefficient of the semiconductor laser in combination with the degree of efficiency loss.

[0080] After determining the impact of the thermal accumulation effect on the operating efficiency of semiconductor lasers, the thermal accumulation effect not only affects the rise in threshold current and the stability of output power, but is also directly related to the laser's heat dissipation management requirements. By evaluating the accuracy of temperature feedback, the thermal accumulation effect can be effectively suppressed, thereby reducing the threshold current of the semiconductor laser, allowing the laser to achieve higher output power under lower driving conditions and improve operating efficiency.

[0081] As an exemplary embodiment, the above step S4 can be performed by Figure 4 The steps S41 to S43 shown implement: S41, determining the power fluctuation degree according to the operating power monitoring curve, and determining the wavelength variation degree according to the output wavelength monitoring curve.

[0082] Exemplarily, the maximum power value and the minimum power value are determined according to the operating power monitoring curve, and the difference between the maximum power value and the minimum power value is used as the degree of power fluctuation; the output wavelength difference between each two adjacent monitoring moments is determined according to the output wavelength monitoring curve, and the average value of all output wavelength differences is used as the degree of wavelength change.

[0083] S42, determining the temperature feedback control accuracy of the semiconductor laser according to the power fluctuation degree, wavelength variation degree and efficiency loss degree.

[0084] Here, temperature feedback control accuracy is the core indicator for measuring the performance of the temperature control system. It refers to the deviation range between the actual system temperature and the target temperature. Its numerical value directly reflects the system's anti-interference ability and stability. The greater the temperature feedback control accuracy, the stronger the semiconductor laser's system anti-interference ability and stability, and the less need for temperature regulation.

[0085] Monitor the output power fluctuation of the laser under different working conditions. Ideally, temperature feedback control should keep the output power at a stable level. A smaller fluctuation range indicates higher control accuracy, that is, the smaller the power fluctuation, the higher the temperature feedback control accuracy of the semiconductor laser. Analyze the stability of the laser output spectrum with temperature changes. When the temperature feedback control accuracy is high, the output wavelength of the laser should be kept within a smaller variation range, which can effectively avoid frequency drift and mode change. That is, the smaller the wavelength variation, the higher the temperature feedback control accuracy of the semiconductor laser. The more significant the thermal accumulation effect, that is, the greater the efficiency loss of the semiconductor laser caused by the thermal accumulation effect, the lower the temperature feedback control accuracy. Therefore, the power fluctuation degree, wavelength variation degree, and efficiency loss degree are inversely proportional to the temperature feedback control accuracy.

[0086] As an example, the calculation formula for the temperature feedback control accuracy of a semiconductor laser can be: Where, Indicates the temperature feedback control accuracy of the semiconductor laser, exp represents the exponential function with the natural constant as the base, and exp (-) is used to achieve negative correlation processing of the data. Indicates the degree of efficiency loss of semiconductor lasers caused by heat accumulation effects. Indicates the degree of power fluctuation, Indicates the degree of wavelength change.

[0087] It should be noted that by conducting a detailed analysis of the thermal accumulation effect and operating efficiency of the actual operation of the semiconductor laser, the control accuracy of the temperature control device of the semiconductor laser is further evaluated, so as to provide reliable data support for subsequent temperature control methods.

[0088] S43, determining an operating state index of the semiconductor laser according to the operating frequency monitoring curve, and determining a temperature control requirement coefficient in combination with the temperature feedback control accuracy.

[0089] The operating frequency affects the thermal dynamic characteristics of the laser. High-frequency operation leads to faster heat accumulation, which may cause the laser to overheat in a short period of time, requiring the temperature control device to respond to changes in a timely manner. The temperature feedback control accuracy can indicate the control accuracy of the temperature control device of the semiconductor laser. The smaller the control accuracy, the greater the demand for temperature control of the semiconductor laser.

[0090] Exemplarily, a normalized value of the negative correlation of the temperature feedback control accuracy is determined, and a normalized value of the operating state indicator is determined; the two normalized values ​​are fused to determine the temperature control requirement coefficient of the semiconductor laser; wherein both normalized values ​​are proportional to the temperature control requirement coefficient.

[0091] Furthermore, the calculation formula for the temperature control demand coefficient can be: Where, represents the temperature control coefficient of the semiconductor laser, th represents the hyperbolic tangent function, which is used to achieve normalization processing. Indicates the temperature feedback control accuracy of the semiconductor laser, Indicates the negative correlation data of temperature feedback control accuracy. Under normal circumstances There will be no zero situation. If there is an extreme situation, you can add a non-zero constant to the denominator of the fraction, such as 0.001. Indicates the average value of all operating frequencies on the operating frequency monitoring curve.

[0092] Thus, this embodiment has determined the temperature control requirement coefficient for controlling the temperature of the semiconductor laser.

[0093] S5, adjusting the default proportional gain value in the PID control module using the temperature control demand coefficient to obtain an adjusted proportional gain value to perform temperature control on the semiconductor laser.

[0094] Embedding a PID control module in the temperature control device to adjust the temperature of the laser in real time not only helps to effectively suppress the heat accumulation effect, but also maintains the stability of the laser's output power and spectral characteristics.

[0095] Exemplarily, the temperature control requirement coefficient is multiplied by the default proportional gain value in the PID control module, and the obtained product is used as the adjusted proportional gain value, and the adjusted proportional gain value is used to control the temperature of the semiconductor laser.

[0096] Furthermore, the temperature control device will provide real-time feedback on the current temperature status and continuously fine-tune the PID control parameters. Based on this feedback, the system will automatically optimize the control parameters to adapt to different working environments and load conditions.

[0097] By using the adjusted proportional gain value to control the temperature of the semiconductor laser, the temperature control device of the semiconductor laser can be effectively optimized. Through optimization, the stability and consistency of the laser output can be ensured, and the modulation bandwidth and response speed of the laser can be improved, so that the semiconductor laser can quickly adapt to environmental changes and load fluctuations, thereby improving the real-time performance of the system.

[0098] Subsequent testing in actual optical communication applications will verify the effectiveness of the PID-controlled temperature control system. The laser's output characteristics, temperature fluctuations, and corresponding communication performance will be recorded. Based on these test results, the system's performance will be analyzed to identify areas for further optimization and adjust the PID parameters to accommodate more complex environmental variations.

[0099] Thus, this embodiment has achieved fast-response semiconductor laser temperature control.

[0100] Another embodiment of the present invention provides a temperature control device for a semiconductor laser, comprising a processor and a memory, wherein the processor is configured to process instructions stored in the memory to implement a temperature control method for a semiconductor laser.

[0101] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A temperature control method for a semiconductor laser, characterized in that: The following steps are involved: Obtaining an operating temperature monitoring curve, an operating power monitoring curve, a threshold current monitoring curve, an output wavelength monitoring curve, and an operating frequency monitoring curve of the semiconductor laser during the current monitoring period; Analyze the complex change characteristics of operating temperature and operating power during laser operation based on the operating temperature monitoring curve and operating power monitoring curve, and determine the heat accumulation effect index in the semiconductor laser; According to the operating temperature monitoring curve, operating power monitoring curve and threshold current monitoring curve, the correlation between the operating temperature change and the operating power change and threshold current change during the operation of the laser is analyzed. Combined with the heat accumulation effect index, the efficiency loss degree of the semiconductor laser caused by the heat accumulation effect is determined; Analyze the temperature feedback control accuracy and thermal dynamic characteristics of the semiconductor laser based on the operating power monitoring curve, output wavelength monitoring curve, and operating frequency monitoring curve, and determine the temperature control requirement coefficient of the semiconductor laser in combination with the degree of efficiency loss; The temperature control requirement coefficient is used to adjust the default proportional gain value in the PID control module to obtain the adjusted proportional gain value for temperature control of the semiconductor laser.

2. A temperature control method for a semiconductor laser according to claim 1, characterized in that: Determining the heat accumulation effect index in the semiconductor laser includes: Analyze the chaotic, frequent, and continuously rising operating temperature changes during the current monitoring period based on the operating temperature monitoring curve to determine the complexity of temperature changes during the operation of the semiconductor laser; Determine the complexity of power variation during the operation of the semiconductor laser based on the operating power monitoring curve; The temperature variation complexity and power variation complexity during the operation of the semiconductor laser are integrated to determine the heat accumulation effect index in the semiconductor laser; wherein, the temperature variation complexity and power variation complexity are both proportional to the heat accumulation effect index.

3. The temperature control method for a semiconductor laser according to claim 2, characterized in that: The step of determining the complexity of temperature changes during operation of the semiconductor laser comprises: Calculate the first difference value between every two operating temperatures according to the operating temperature monitoring curve, and determine the average value of all the first difference values ​​as the degree of temperature change disorder; Calculating the time interval between each two adjacent extreme value points based on the operating temperature monitoring curve, and determining the frequency of temperature changes based on each time interval value; wherein the time interval value is inversely proportional to the frequency of temperature changes; Calculating a second difference between the operating temperature at a subsequent monitoring moment and the operating temperature at a previous monitoring moment according to the operating temperature monitoring curve, and determining an average value of all the second difference values ​​as the degree of continuous temperature increase; The complexity of temperature changes during the operation of the semiconductor laser is determined by integrating the degree of disorder of temperature changes, the frequency of temperature changes and the degree of continuous temperature increase; among them, the degree of disorder of temperature changes, the frequency of temperature changes and the degree of continuous temperature increase are all proportional to the complexity of temperature changes.

4. The temperature control method for a semiconductor laser according to claim 1, characterized in that: Determining the degree of efficiency loss of the semiconductor laser caused by the heat accumulation effect includes: Determine the slope values ​​corresponding to every two adjacent data points in the operating temperature monitoring curve, the operating power monitoring curve, and the threshold current monitoring curve, and select each positive temperature slope value from each slope value corresponding to the operating temperature monitoring curve; Recording each monitoring sub-period of a positive temperature slope value as a target sub-period, and filtering out the power slope value and current slope value of each target sub-period from the slope values ​​corresponding to the operating power monitoring curve and the threshold current monitoring curve; The efficiency loss degree is determined according to the difference between the positive temperature slope value and the power slope value, the difference between the positive temperature slope value and the current slope value, and the heat accumulation effect indicator in the same target sub-period.

5. The temperature control method for a semiconductor laser according to claim 4, characterized in that: The determining the efficiency loss degree according to the difference between the positive temperature slope value and the power slope value, the difference between the positive temperature slope value and the current slope value, and the heat accumulation effect indicator in the same target sub-period includes: Determining an evaluation value of the inhibitory effect of the heat accumulation effect on the operating power of the semiconductor laser based on a third difference between the positive temperature slope value and the power slope value in the same target sub-period and in combination with the heat accumulation effect index; wherein the third difference and the heat accumulation effect index are both proportional to the inhibitory effect evaluation value; Based on a fourth difference value between the positive temperature slope value and the current slope value in the same target sub-period, combined with the inhibition effect evaluation value, the degree of efficiency loss of the semiconductor laser caused by the heat accumulation effect is determined; wherein the fourth difference value and the inhibition effect evaluation value are both proportional to the degree of efficiency loss.

6. The temperature control method for a semiconductor laser according to claim 1, characterized in that: Determining the temperature control requirement coefficient of the semiconductor laser includes: Determine the degree of power fluctuation based on the operating power monitoring curve, and determine the degree of wavelength variation based on the output wavelength monitoring curve; Determining the temperature feedback control accuracy of the semiconductor laser based on the degree of power fluctuation, the degree of wavelength variation, and the degree of efficiency loss; wherein the degree of power fluctuation, the degree of wavelength variation, and the degree of efficiency loss are all inversely proportional to the temperature feedback control accuracy; The operating state index of the semiconductor laser is determined according to the operating frequency monitoring curve, and the temperature control requirement coefficient is determined in combination with the temperature feedback control accuracy.

7. The temperature control method for a semiconductor laser according to claim 6, characterized in that: Determining the power fluctuation degree according to the operating power monitoring curve and determining the wavelength variation degree according to the output wavelength monitoring curve includes: Determine a maximum power value and a minimum power value according to the operating power monitoring curve, and use the difference between the maximum power value and the minimum power value as the power fluctuation degree; The output wavelength difference between every two adjacent monitoring moments is determined according to the output wavelength monitoring curve, and the average value of all the output wavelength differences is used as the wavelength change degree.

8. The temperature control method for a semiconductor laser according to claim 6, characterized in that: The step of determining the operating state index of the semiconductor laser according to the operating frequency monitoring curve and determining the temperature control requirement coefficient in combination with the temperature feedback control accuracy includes: Determining a normalized value of the negative correlation of the temperature feedback control accuracy and determining a normalized value of the operating state indicator; The two normalized values ​​are combined to determine the temperature control requirement coefficient of the semiconductor laser; wherein both the normalized values ​​are proportional to the temperature control requirement coefficient.

9. The temperature control method for a semiconductor laser according to claim 1, characterized in that: The method of adjusting the default proportional gain value in the PID control module by using the temperature control demand coefficient to obtain the adjusted proportional gain value includes: The temperature control demand coefficient is multiplied by the default proportional gain value in the PID control module, and the product is used as the adjusted proportional gain value.

10. A temperature control device for a semiconductor laser, characterized in that: The system comprises a processor and a memory, wherein the processor is used to process instructions stored in the memory to implement a temperature control method for a semiconductor laser according to any one of claims 1 to 9.

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