DFB laser device mode hopping processing method, control device and heating equipment

Abstract

The invention discloses a DFB laser device mode hopping processing method, a control device and a heating device, and relates to the technical field of DFB laser devices, the DFB laser device is provided with a heating resistor, and the method comprises the following steps: applying a voltage signal to the heating resistor to heat the heating resistor; and adjusting a voltage signal applied to the heating resistor to enable the temperature of the DFB laser to be within a preset temperature range. The DFB laser is heated to the preset temperature range through the heating resistor, so that the mode hopping risk of the DFB laser is reduced.

Description

Technical Field

[0001] This application relates to the technical field of DFB lasers, and in particular to a method, control device and heating equipment for handling mode skipping in a DFB laser. Background Technology

[0002] With the rapid development of optical communication technology, the signal transmission rate of optical modules is constantly increasing. High-speed optical modules with single-wavelength 400Gbps, 1.6T, and even 3.2T have become an industry trend, and DFB lasers, as the core light source, are widely used in silicon photonics modules. However, mode hopping has become one of the key factors restricting the performance and reliability of lasers. Mode hopping refers to the phenomenon that the lasing mode of a DFB laser suddenly jumps from one longitudinal mode to another during operation. Spectroscopically, this results in two or more peaks, leading to output wavelength drift, optical power fluctuations, and consequently, serious problems such as link flapping, increased bit error rate, and data packet loss, affecting the reliability of the communication system. The root cause of mode hopping is that the grating frequency-selective wavelength and the peak value of the gain spectrum of a DFB laser drift at different rates with temperature (approximately 0.1 nm / ℃ for the former and approximately 0.5 nm / ℃ for the latter). When the temperature changes significantly, their relative positions become misaligned, leading to intensified mode competition and causing mode hopping. In practical applications, the mode-hopping ranges of different lasers are discrete. Some exhibit mode-hopping in the low-temperature range (below 10℃), while others hop in the medium-temperature range (40℃~60℃). However, the operating temperature range of optical modules is typically 0℃~70℃ (800G and below) or 15℃~70℃ (1.6T), which poses a significant challenge to mode-hopping screening. Currently, production lines primarily use spectrometers to detect mode hopping, screening by observing the presence of multiple peaks in the spectrum or calculating whether the side-mode suppression ratio (SMSR) meets the standard. However, this method has drawbacks: spectrometers are expensive, increasing production line investment costs; they can only perform sampling or offline testing, failing to achieve online real-time monitoring; even with temperature cycling testing, it is still impossible to effectively intercept all potentially mode-hopping lasers; and the testing process is complex, time-consuming, and passively selective. Summary of the Invention

[0003] The main purpose of this application is to propose a method, control device, and heating equipment for handling mode hopping in DFB lasers, which aims to reduce the risk of mode hopping in DFB lasers by heating the DFB laser to a preset temperature range through heating resistors.

[0004] To achieve the above objectives, this application proposes a DFB laser mode hopping processing method, wherein the DFB laser is equipped with a heating resistor, and the method includes: A voltage signal is applied to the heating resistor to raise its temperature; Adjust the voltage signal applied to the heating resistor so that the temperature of the DFB laser is within a preset temperature range.

[0005] Optionally, the preset temperature range is 65℃~70℃.

[0006] Optionally, the step of adjusting the voltage signal applied to the heating resistor includes: The device temperature of the DFB laser is obtained; Based on the preset temperature control logic, the device temperature, and the preset temperature range, the voltage signal applied to the heating resistor is adjusted.

[0007] Optionally, the preset temperature control logic is a PID temperature control algorithm.

[0008] Optionally, the method further includes: The device temperature of the DFB laser is obtained; If, based on the device temperature, the temperature of the DFB laser is determined to be less than the lower limit of the preset temperature range, the step of applying a voltage signal to the heating resistor to raise the temperature of the heating resistor is executed. If, based on the device temperature, the temperature of the DFB laser is determined to be greater than the upper limit of the preset temperature range, the step of applying a voltage signal to the heating resistor to raise its temperature is stopped.

[0009] This application also proposes a control device, the control device comprising: a memory, a processor, and a control program for DFB laser mode hopping stored in the memory and executable on the processor, the control program for DFB laser mode hopping being configured to implement the DFB laser mode hopping processing method as described in any of the preceding claims.

[0010] This application also proposes a heating device, which includes a heating resistor, a power module, and a control device as described above; The power module is electrically connected to the heating resistor, and the control device is electrically connected to the power module. The control device is used to control the power module to apply a voltage signal to the heating resistor so that the temperature of the DFB laser is within a preset temperature range.

[0011] Optionally, the heating resistor is a thin-film heating resistor.

[0012] This application proposes a mode hopping handling method for a DFB laser. The DFB laser is equipped with a heating resistor. The method includes: applying a voltage signal to the heating resistor to raise its temperature; and adjusting the voltage signal applied to the heating resistor to keep the temperature of the DFB laser within a preset temperature range. Thus, through the above configuration, this DFB laser mode hopping handling method enables the DFB laser to adjust the voltage signal applied to the heating resistor, controlling the temperature of the DFB laser within the preset temperature range, thereby effectively reducing the risk of mode hopping. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0014] Figure 1 A flowchart illustrating an embodiment of the DFB laser mode skipping processing method provided in this application; Figure 2 A schematic flowchart of another embodiment of the DFB laser mode skipping processing method provided in this application; Figure 3 This is a flowchart illustrating another embodiment of the DFB laser mode skipping processing method provided in this application.

[0015] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0016] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0017] With the rapid development of optical communication technology, the signal transmission rate of optical modules is constantly increasing. High-speed optical modules with single-wavelength 400Gbps, 1.6T, and even 3.2T have become an industry trend, and DFB lasers, as the core light source, are widely used in silicon photonics modules. However, mode hopping has become one of the key factors restricting the performance and reliability of lasers. Mode hopping refers to the phenomenon that the lasing mode of a DFB laser suddenly jumps from one longitudinal mode to another during operation. Spectroscopically, this results in two or more peaks, leading to output wavelength drift, optical power fluctuations, and consequently, serious problems such as link flapping, increased bit error rate, and data packet loss, affecting the reliability of the communication system. The root cause of mode hopping is that the grating frequency-selective wavelength and the peak value of the gain spectrum of a DFB laser drift at different rates with temperature (approximately 0.1 nm / ℃ for the former and approximately 0.5 nm / ℃ for the latter). When the temperature changes significantly, their relative positions become misaligned, leading to intensified mode competition and causing mode hopping. In practical applications, the mode-hopping ranges of different lasers are discrete. Some exhibit mode-hopping in the low-temperature range (below 10℃), while others hop in the medium-temperature range (40℃~60℃). However, the operating temperature range of optical modules is typically 0℃~70℃ (800G and below) or 15℃~70℃ (1.6T), which poses a significant challenge to mode-hopping screening. Currently, production lines primarily use spectrometers to detect mode hopping, screening by observing the presence of multiple peaks in the spectrum or calculating whether the side-mode suppression ratio (SMSR) meets the standard. However, this method has drawbacks: spectrometers are expensive, increasing production line investment costs; they can only perform sampling or offline testing, failing to achieve online real-time monitoring; even with temperature cycling testing, it is still impossible to effectively intercept all potentially mode-hopping lasers; and the testing process is complex, time-consuming, and passively selective.

[0018] To address this, this application proposes a method for handling mode skipping in DFB lasers, wherein a heating resistor is installed on the DFB laser. Optionally, the heating resistor can be a thin-film heating resistor, a metal film heating resistor, or other similar type. In one example, the heating resistor is a thin-film heating resistor, fabricated using microelectronic thin-film technology. It can be mounted parallel to the DFB laser, and its electrode dimensions are compatible with wire bonding (WB) technology, making it compatible with existing optical module packaging processes without requiring changes to production line equipment or processes.

[0019] The heating equipment also includes a control device for storing and executing the methods described below. Optionally, the control device can be implemented using a main controller, such as an MCU, PLC, DSP (Digital Signal Processor), SOC (System on Chip), FPGA (Field Programmable Gate Array), etc.

[0020] Please see Figure 1 In one embodiment of this application, the DFB laser mode hopping processing method includes: Step S100: Apply a voltage signal to the heating resistor to raise its temperature; Step S200: Adjust the voltage signal applied to the heating resistor so that the temperature of the DFB laser is within the preset temperature range.

[0021] In this embodiment, optionally, the control device controls the power module that forms a circuit with the heating resistor, so that the power module outputs a corresponding voltage signal to the heating resistor, thereby causing the heating resistor to heat up.

[0022] Alternatively, the heating resistor can be powered by controlling a switching circuit connected in series in the circuit between the power supply and the heating resistor. In one example, the control device can use PWM to control the switching circuit to apply a voltage signal corresponding to the heating resistor.

[0023] Optionally, the control device can also integrate its own power supply unit and directly output voltage signals to the heating resistor. In one example, the control device uses a chip with an integrated power management unit (PMU) and programmable output functionality. The heating resistor is directly powered by the chip. The control device runs a temperature control algorithm based on temperature feedback, calculates the required heating power, and configures the electrical parameters output by the chip directly through internal registers. Optionally, a programmable voltage output method is used, where the chip's internal PMU outputs a corresponding DC voltage to the heating resistor according to a set value. Optionally, a programmable current output method is used, where the chip's internal PMU outputs a corresponding constant current flowing through the heating resistor according to a set value. Optionally, a programmable power output method is used, where the chip's internal PMU directly outputs the corresponding power according to a set value. The heating resistor generates heat when energized, which is transferred to the adjacent DFB laser via thermal conduction. This example integrates power supply and control functions into a single chip, eliminating the need for external switching circuits and independent power modules.

[0024] Optionally, the preset temperature range can be pre-set by the R&D personnel within the control device. In one example, the preset temperature range is 65℃~70℃, based on a comprehensive consideration of the DFB laser's mode hopping characteristics, data analysis, and the optical module's operating temperature range. Mode hopping occurs because the grating selection wavelength and gain spectrum peak of the DFB laser drift at different rates with temperature. When the temperature changes significantly, their relative positions become misaligned, triggering mode competition. The standard operating temperature range of the optical module is typically 0℃~70℃ (800G and below) or 15℃~70℃ (1.6T). Setting the lower limit of the preset temperature range to 65℃ and the upper limit to 70℃ aligns with the module's maximum operating temperature, preventing overheating. Through a closed-loop feedback control system, the temperature detection module acquires the DFB laser temperature, and the control device uses a PID algorithm to dynamically adjust the power supply voltage of the heating resistor, locking the DFB laser's operating temperature within the 65℃~70℃ range, thereby reducing the risk of mode hopping.

[0025] Optionally, the preset temperature range can also be generated by the control device itself. For example, the control device can generate the corresponding preset temperature range based on the generation logic preset by the R&D personnel and the operating conditions of the DFB laser.

[0026] Optionally, the control device can output a corresponding voltage signal to the heating resistor based on the voltage signal-preset temperature range logic and preset temperature range preset by the researchers.

[0027] Optionally, the control device can detect the temperature of the DFB laser using a temperature detection module and adjust the voltage signal applied across the heating resistor based on the temperature and the process described in the above embodiment, so that the temperature of the DFB laser is within a preset temperature range. The temperature detection module can be implemented using an NTC thermistor, a thermocouple temperature detection module, or the like. In one example, the temperature detection module is an NTC temperature detection module composed of NTC thermistors, which are placed close to the DFB laser. The control device adjusts the voltage signal applied to the heating resistor based on the detection results output by the NTC temperature detection module, so that the temperature of the DFB laser is within the preset temperature range.

[0028] Thus, through the above settings, the DFB laser mode hopping processing method of this application enables the DFB laser to adjust the voltage signal applied to the heating resistor, control the temperature of the DFB laser within a preset temperature range, and effectively reduce the risk of mode hopping of the DFB laser.

[0029] Optionally, refer to Figure 2 In one embodiment of this application, the step of adjusting the voltage signal applied to the heating resistor includes: Step S300: Obtain the equipment temperature of the DFB laser; Step S400: Based on the preset temperature control logic, the device temperature and the preset temperature range, adjust the voltage signal applied to the heating resistor.

[0030] In this embodiment, the control device can acquire the equipment temperature of the DFB laser through a temperature detection module. Optionally, the temperature detection module can use an analog temperature sensor. The temperature sensor detects the temperature of the DFB laser and outputs a temperature-related voltage or resistance signal. The control device acquires this analog signal through a built-in analog-to-digital converter (ADC), converts it into a digital quantity, and then calculates the actual workpiece temperature based on the characteristic curve of the temperature sensor. Optionally, the temperature detection module can use a digital temperature sensor. The control device establishes a direct communication connection with the temperature sensor to obtain the equipment temperature of the DFB laser detected by the temperature sensor. For example, the control device establishes a communication connection with the temperature sensor through a communication interface such as I²C, SPI, or a single bus, and obtains the equipment temperature of the DFB laser detected by the temperature sensor through the corresponding communication protocol.

[0031] In this embodiment, the preset temperature control logic can be a PID temperature control algorithm, a fuzzy control algorithm, or a lookup table control logic, etc., to achieve closed-loop feedback control. Through this process, the control device dynamically adjusts the supply voltage of the heating resistor based on the temperature feedback, so that the temperature of the DFB laser is stabilized within the preset temperature range.

[0032] In one example, the preset temperature control logic is a PID temperature control algorithm used to achieve closed-loop control of the DFB laser temperature. The control device obtains the equipment temperature of the DFB laser through a temperature detection module and compares it with a preset temperature range, using the midpoint of the range as the target temperature value to calculate the temperature deviation. Subsequently, the control device runs the PID algorithm, calculates the control quantity corresponding to the required heating power based on the current deviation, historical cumulative deviation, and deviation change rate, and outputs the corresponding control signal to adjust the power supply state of the heating resistor. After the heating resistor is energized, it generates heat, which is transferred to the DFB laser through heat conduction, causing its temperature to gradually change. When the equipment temperature is lower than the target value, the deviation is positive, the PID algorithm output increases, and the heating power increases; when the equipment temperature is higher than the target value, the deviation is negative, the PID algorithm output decreases, and the heating power decreases; when the equipment temperature approaches the target value, the integral term eliminates steady-state error, and the derivative term suppresses temperature overshoot, so that the laser temperature is smoothly stabilized near the target value. The above process is executed cyclically with a fixed period, forming a closed-loop negative feedback control, ensuring that the DFB laser temperature is always stable within the preset temperature range, thereby reducing the risk of mode hopping caused by temperature fluctuations.

[0033] Optionally, such as Figure 3 As shown, in one embodiment, the method further includes: Step S300: Obtain the equipment temperature of the DFB laser; Step S500: Based on the equipment temperature, if it is determined that the temperature of the DFB laser is less than the lower limit of the preset temperature range, the step of applying a voltage signal to the heating resistor to raise the temperature of the heating resistor is executed. Step S600: Based on the device temperature, if it is determined that the temperature of the DFB laser is greater than the upper limit of the preset temperature range, stop the step of applying a voltage signal to the heating resistor to raise the temperature of the heating resistor.

[0034] In this embodiment, the control device acquires the device temperature of the DFB laser through a temperature detection module and compares it with the lower and upper limits of a preset temperature range. Optionally, when the control device determines that the current temperature of the DFB laser is lower than the lower limit of the preset temperature range based on the device temperature, a heating step is executed. A voltage signal is applied to the heating resistor, causing it to be energized and heated. The generated heat is transferred to the adjacent DFB laser through thermal conduction, causing its temperature to gradually rise. During the heating process, the control device acquires the device temperature. When the control device determines that the current temperature of the DFB laser has risen to the preset temperature range based on the device temperature, the current heating state is maintained, allowing the heating resistor to continue heating at the existing power to maintain temperature stability. Optionally, when the control device determines that the current temperature of the DFB laser is higher than the upper limit of the preset temperature range based on the device temperature, the heating step is stopped, i.e., the voltage signal applied to the heating resistor is stopped or the applied voltage signal is reduced, causing the heating resistor to stop heating or reduce its heating power to prevent the laser temperature from continuing to rise and causing overshoot. As the heating resistor stops heating, the laser temperature gradually decreases due to ambient heat dissipation. When the temperature falls below the lower limit again, the control device restarts the heating process. The above process is executed cyclically at a certain period, forming a hysteresis switching control based on temperature threshold comparison. Through the alternating action of heating and stopping heating, the temperature of the DFB laser is always maintained within the preset temperature range of 65℃~70℃, thereby effectively reducing the risk of mode skipping caused by temperature fluctuations.

[0035] This application also proposes a control device, which includes: a memory, a processor, and a DFB laser mode hopping control program stored in the memory and executable on the processor, the DFB laser mode hopping control program being configured to implement the DFB laser mode hopping processing method as described above.

[0036] It is worth noting that since the control device of this application includes the above-mentioned DFB laser mode hopping processing method, the control device of this application also includes all the above-mentioned embodiments of the DFB laser mode hopping processing method and the effects of each embodiment, which will not be repeated here.

[0037] This application also proposes a heating device, which includes a heating resistor, a power module and the control device described above; The power module is electrically connected to the heating resistor, and the control device is electrically connected to the power module. The control device is used to control the power supply module to apply a voltage signal to the heating resistor so that the temperature of the DFB laser is within a preset temperature range.

[0038] It is worth noting that since the heating device of this application includes the above-mentioned control device, the heating device of this application also includes embodiments of all the above-mentioned control devices and the effects of each embodiment, which will not be repeated here.

[0039] The above description is merely an exemplary embodiment of this application and does not limit the patent scope of this application. Any equivalent structural transformations made based on the technical concept of this application and the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.

Claims

1. A method for handling mode hopping in a DFB laser, characterized in that, The DFB laser is equipped with a heating resistor, and the method includes: A voltage signal is applied to the heating resistor to raise its temperature; Adjust the voltage signal applied to the heating resistor so that the temperature of the DFB laser is within a preset temperature range.

2. The DFB laser mode hopping processing method as described in claim 1, characterized in that, The preset temperature range is 65℃~70℃.

3. The DFB laser mode hopping processing method as described in claim 1, characterized in that, The step of adjusting the voltage signal applied to the heating resistor includes: The device temperature of the DFB laser is obtained; Based on the preset temperature control logic, the device temperature, and the preset temperature range, the voltage signal applied to the heating resistor is adjusted.

4. The DFB laser mode hopping processing method as described in claim 3, characterized in that, The preset temperature control logic is a PID temperature control algorithm.

5. The DFB laser mode hopping processing method according to any one of claims 1 to 4, characterized in that, The method further includes: The device temperature of the DFB laser is obtained; If, based on the device temperature, the temperature of the DFB laser is determined to be less than the lower limit of the preset temperature range, the step of applying a voltage signal to the heating resistor to raise the temperature of the heating resistor is executed. If, based on the device temperature, the temperature of the DFB laser is determined to be greater than the upper limit of the preset temperature range, the step of applying a voltage signal to the heating resistor to raise its temperature is stopped.

6. A control device, characterized in that, The control device includes: a memory, a processor, and a DFB laser mode hopping control program stored in the memory and executable on the processor, the DFB laser mode hopping control program being configured to implement the DFB laser mode hopping processing method as described in any one of claims 1 to 5.

7. A heating device, characterized in that, The heating device includes a heating resistor, a power module, and a control device as described in claim 6; The power module is electrically connected to the heating resistor, and the control device is electrically connected to the power module. The control device is used to control the power module to apply a voltage signal to the heating resistor so that the temperature of the DFB laser is within a preset temperature range.

8. The heating device as described in claim 7, characterized in that, The heating resistor is a thin-film heating resistor.

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