Backup high-density monolithic multi-channel rec laser

Abstract

The application discloses a backup type high-density monolithic integrated multi-channel REC laser, characterized in that the multi-channel REC laser comprises an REC laser array, a wavelength division multiplexing combiner, an EDFA amplifier, a coupler, a first wavelength division multiplexing demultiplexer, a second wavelength division multiplexing demultiplexer, a first photodetector, a second photodetector, a channel switching module and a temperature control adjustment module. The backup technology can effectively improve the stability and reliability of the system, and ensure that the whole system can still maintain normal operation and provide stable output when a fault occurs. Meanwhile, the temperature control adjustment module is used to adjust the internal heat of the multi-channel REC laser, so that the set wavelength can be recovered as soon as possible after switching, and the switching efficiency and success rate are improved.

Description

Technical Field

[0001] This invention belongs to the field of laser technology, specifically relating to a backup-type high-density monolithic integrated multi-channel REC (Reconstruction-Equivalent-Chirp) laser. Background Technology

[0002] Optical communication is a communication technology that uses light to transmit information. It is a high-speed, high-bandwidth, low-loss, and low-interference communication method. In the light source section, semiconductor lasers have many advantages, such as small size, low power consumption, and suitability for mass production, making them a core component in optical communication systems. Today's optical communication networks face the challenge of processing massive amounts of information, requiring greater bandwidth and faster transmission speeds. In critical application areas, especially in high-precision applications requiring long-term operation and continuous work in military and aerospace fields, multi-channel lasers capable of simultaneously outputting 8, 16, or even more wavelengths are typically used to improve signal transmission capacity, data transmission rate, and anti-interference performance.

[0003] However, since laser arrays consist of numerous parts, a failure in a single laser can affect the normal operation of the entire system. Therefore, using multi-channel lasers with backup capabilities in optical communication systems, with individual backups for each channel's laser, can overcome the single point of failure problem, improving system stability and reliability while ensuring efficiency and quality.

[0004] To manufacture monolithically integrated multichannel semiconductor lasers, it is typically necessary to individually control the wavelength of each laser in the laser array. This requires precise control of the grating period of each laser, necessitating extremely high-precision fabrication methods. Currently, the primary fabrication method is electron beam lithography (EBL). EBL utilizes focused electrons with extremely short wavelengths to directly act on the electron-sensitive photoresist surface, creating micro / nano structures that conform to the design pattern. This technology has the advantage of directly depicting fine patterns, and the short wavelength of the high-energy electron beam (less than 1 nm) avoids diffraction effects. However, in this method, each transistor must be precisely positioned and fabricated at the micrometer level, resulting in low production efficiency and exceptionally high processing and equipment costs. When chip structures are diverse, with significant differences in fine structures and high density of structural variations, the required processing time increases exponentially. Furthermore, the processing time and cycle time are difficult to control, making it unsuitable for mass production. Therefore, it is extremely difficult to fabricate monolithic integrated semiconductor laser arrays with a large number of channels using electron beam lithography.

[0005] Reconstruction-equivalent-chirp (REC) technology, based on holographic exposure followed by conventional photolithography, can equivalently realize complex grating structures. Compared to traditional processes, the biggest advantage of REC technology lies in its ability to achieve precise control over the grating structure, thereby improving the wavelength accuracy of the laser by approximately two orders of magnitude, specifically controlling the wavelength accuracy to within ±0.2 nm. Utilizing the high-precision wavelength control capability of REC technology, monolithic integrated semiconductor laser arrays that simultaneously output dozens of wavelengths can be fabricated, offering significant advantages in integrability, reliability, and manufacturing cost. However, due to their high integration density, multi-channel REC lasers accumulate substantial heat inside the chip during high-power or long-term operation, leading to poor laser performance, easy wavelength shift, and poor system stability. Currently, there is no backup switching technology solution based on multi-channel REC lasers. Summary of the Invention

[0006] Technical problem solved: This invention discloses a backup-type high-density monolithic integrated multi-channel REC (Reconstruction-Equivalent-Chirp) laser. Through backup technology, the stability and reliability of the system can be effectively improved, ensuring that the entire system can still maintain normal operation and provide stable output when a fault occurs. At the same time, a temperature control adjustment module is used to regulate the internal heat of the multi-channel REC laser, ensuring that the set wavelength is restored as soon as possible after switching, thereby improving switching efficiency and success rate.

[0007] Technical solution:

[0008] A backup-type high-density monolithic integrated multi-channel REC laser, the multi-channel REC laser comprising a REC laser array, a wavelength division multiplexing multiplexer, an EDFA amplifier, a coupler, a first wavelength division multiplexing demultiplexer, a second wavelength division multiplexing demultiplexer, a first photodetector, a second photodetector, a channel switching module, and a temperature control adjustment module;

[0009] The REC laser array comprises 2N REC lasers, divided into N groups of two. In each group, one of the two REC lasers is the main laser used during normal operation, and the other is the backup laser activated when the main laser fails; N is a positive integer greater than 1.

[0010] The wavelength division multiplexing combiner is used to couple N different channel wavelength optical signals simultaneously output by the REC laser array to generate multiplexed optical signals, which are then amplified by the EDFA amplifier.

[0011] The coupler distributes the power of the optical multiplexed signal amplified by the EDFA amplifier in a 1:1 ratio. The two optical multiplexed signals are decomposed into N optical signals by the first wavelength division multiplexing demultiplexer and the second wavelength division multiplexing demultiplexer, respectively. The first photodetector converts the N optical signals output by the first wavelength division multiplexing demultiplexer into N first electrical signals and sends them to the temperature control adjustment module. The second photodetector converts the N optical signals output by the second wavelength division multiplexing demultiplexer into N second electrical signals and sends them to the channel switching module.

[0012] The channel switching module amplifies the N second electrical signals, converts the amplified second electrical signals into corresponding digital signals, calculates the optical power corresponding to the N digital signals, and determines that the main laser of the channel has failed if the optical power of any channel is lower than the preset optical power threshold. It then generates optical switch signals for the main laser and its corresponding backup laser, shuts down the main laser, starts the corresponding backup laser, and defines the backup laser as the main laser. The failed main laser is defined as the backup laser.

[0013] The temperature control adjustment module includes a semiconductor cooler installed on one side of the REC laser array and individual heaters installed at each of the 2N REC lasers. The temperature control adjustment module processes the N first electrical signals to calculate the optical power corresponding to the N different wavelength signal lights. If the optical power of any one of them is lower than the preset optical power threshold, it is determined that the main laser corresponding to that wavelength has failed. A timer is started, and the semiconductor cooler is turned on to cool the REC laser array as a whole. When the timer exceeds the preset switching time threshold, if the optical power of the laser at that wavelength still has not reached the preset optical power threshold, the individual heater of the backup laser corresponding to the failed main laser is turned on to heat the backup laser at that wavelength individually until the optical power of the laser at that wavelength reaches the preset optical power threshold.

[0014] Furthermore, the channel switching module includes a preamplifier circuit, an A / D conversion circuit, an FPGA unit, an optical switch driving circuit, and a 1*2N optical switch connected in sequence;

[0015] The preamplifier circuit amplifies the N-channel second electrical signals and then sends them to the A / D conversion circuit to convert them into corresponding digital signals.

[0016] The FPGA unit processes the digital signals output by the A / D conversion circuit and calculates the optical power corresponding to the N digital signals. If the optical power of any one of the signals is lower than the preset optical power threshold, it is determined that the main laser of that signal has failed. The unit generates optical switch signals for the main laser and its corresponding backup laser and sends them to the optical switch drive circuit. At the same time, the backup laser is defined as the main laser and the failed main laser is defined as the backup laser.

[0017] The input terminal of the 1*2N optical switch is connected to the output terminal of the optical switch driving circuit. The 1*2N optical switch has 2N output terminals, which are respectively connected to 2N REC lasers. The optical switch driving circuit shuts down the main laser and starts the corresponding backup laser according to the received optical switch signal.

[0018] Furthermore, when the FPGA unit performs channel switching, it decodes the backup channel signal that replaces the main channel into a drive signal, controls the optical switch through the drive circuit, and finally feeds back the current status information of the optical switch to the FPGA. The FPGA compares the switched channel signal with the optical switch signal. If they are the same, the channel switching is successful; if they are different, the channel switching fails.

[0019] Furthermore, the 1×2N optical switch has one input fiber and 2N output fibers, and the 2N REC lasers are connected one-to-one with the 2N output fibers; the driving voltage range of the 1×2 optical switch is 5V to 6V. When the optical switch is driven by a voltage, it is in the off state. When the optical switch is not driven by a voltage or is driven by a very small voltage, it is in the on state.

[0020] Furthermore, the temperature control adjustment module includes an MCU unit, a temperature control circuit, and a temperature adjustment unit connected in sequence;

[0021] The temperature control unit includes a semiconductor cooler installed on one side of the REC laser array and individual heaters installed one-to-one at each of the 2N REC lasers;

[0022] The MCU unit includes a signal judgment component, a timing component, a backup laser management component, a cooling component, and a heating component;

[0023] The signal judgment component processes the N first electrical signals and calculates the optical power corresponding to the N different wavelength signal lights. If the optical power of any one of them is lower than the preset optical power threshold, it is determined that the main laser corresponding to that wavelength has failed. A timing signal is generated and sent to the timing component to start timing. At the same time, the cooling component is triggered, and the cooling component generates a cooling start signal to the temperature control circuit to start the semiconductor cooler. The timing stops and is cleared until the optical power of the laser of that wavelength reaches the preset optical power threshold.

[0024] The signal judgment component continuously judges the optical power of the optical signal corresponding to the wavelength. When the recording time of the timing component exceeds the preset switching time threshold, and the optical power of the laser of that wavelength still does not reach the preset optical power threshold, the heating component is triggered. The heating component generates a heating start signal to the temperature control circuit to start the separate heater of the backup laser corresponding to the half-faulted main laser. The backup laser is heated separately until the optical power of the laser of that wavelength reaches the preset optical power threshold. The timing is then stopped, the timing is cleared, and the backup laser management component is triggered to update the backup laser list, defining the backup laser as the main laser and the faulty main laser as the backup laser.

[0025] Furthermore, the channel switching module periodically sends its own stored list of backup lasers to the MCU unit, which then compares the backup laser lists stored in both modules. If an error is found during the comparison, an alarm signal is generated.

[0026] Furthermore, the temperature control adjustment module also includes a timing display component;

[0027] The timing display component is used to display the full duration of the laser switching.

[0028] Furthermore, the semiconductor cooler employs a thermoelectric cooler coupled to the REC laser array.

[0029] Furthermore, the individual heater is a resistive heater mounted on the laser.

[0030] Beneficial effects:

[0031] First, the backup high-density monolithically integrated multi-channel REC laser of the present invention adopts the reconstruction equivalent chirp technology, which overcomes the problems of low production efficiency, high equipment and processing costs, and difficulty in controlling the cycle of electron beam lithography technology. This makes the backup high-density multi-channel laser have good scalability, and the number of channels can be increased or decreased as needed to meet the needs of different application scenarios. At the same time, each channel can be independently optimized and adjusted to improve the overall performance and flexibility of the system.

[0032] Second, the backup high-density monolithic integrated multi-channel REC laser of the present invention has a backup function. When one or more channels of the laser fail, the external control unit monitors the operating status of the channel and quickly switches the backup laser to replace the faulty laser in order to maintain normal laser output.

[0033] Third, the backup high-density monolithic integrated multi-channel REC laser of the present invention adds a temperature control adjustment module on the basis of channel switching, which can monitor the output optical power of the multi-channel REC laser in real time, and uses a semiconductor cooler and a separate heater to effectively and accurately control the temperature of multiple lasers on a chip in a timely manner, intuitively displaying the channel switching time, and realizing the stability of output wavelength and efficient channel switching.

[0034] Fourth, the backup-type high-density monolithic integrated multi-channel REC laser of the present invention uses an optical switch to minimize the switching time. When a channel switch occurs, very short transient disturbances such as power and phase will only occur momentarily and can quickly recover to a steady state, thereby achieving efficient and stable laser output. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the backup-type high-density monolithic integrated multi-channel REC laser of the present invention;

[0036] Figure 2 A schematic diagram of a 2-backup 16-channel laser array based on the reconfigurable equivalent chirp (REC) technique;

[0037] Figure 3 This is a flowchart of the temperature adjustment module's workflow.

[0038] Figure 4 This is a schematic diagram of the output characteristics of the REC laser array chip when the channel 1 laser fails in an embodiment of the present invention;

[0039] Figure 5 This is a schematic diagram of the output characteristics of the REC laser array chip after switching to the backup laser in an embodiment of the present invention. Detailed Implementation

[0040] The following embodiments are provided to enable those skilled in the art to more fully understand the present invention, but do not limit the invention in any way.

[0041] This invention discloses a backup-type high-density monolithic integrated multi-channel REC laser, wherein the multi-channel REC laser includes a REC laser array, a wavelength division multiplexing multiplexer, an EDFA amplifier, a coupler, a first wavelength division multiplexing demultiplexer, a second wavelength division multiplexing demultiplexer, a first photodetector, a second photodetector, a channel switching module, and a temperature control adjustment module.

[0042] The REC laser array includes 2N REC lasers, which are divided into N groups of two. In each group, one of the two REC lasers is the main laser used during normal operation, and the other is the backup laser activated when the main laser fails.

[0043] The wavelength division multiplexing combiner is used to couple N different channel wavelength optical signals simultaneously output by the REC laser array to generate multiplexed optical signals, which are then amplified by the EDFA amplifier.

[0044] The coupler distributes the power of the optical multiplexed signal amplified by the EDFA amplifier in a 1:1 ratio. The two optical multiplexed signals are decomposed into N optical signals by the first wavelength division multiplexing demultiplexer and the second wavelength division multiplexing demultiplexer, respectively. The first photodetector converts the N optical signals output by the first wavelength division multiplexing demultiplexer into N first electrical signals and sends them to the temperature control adjustment module. The second photodetector converts the N optical signals output by the second wavelength division multiplexing demultiplexer into N second electrical signals and sends them to the channel switching module.

[0045] The channel switching module amplifies the N second electrical signals, converts the amplified second electrical signals into corresponding digital signals, processes the digital signals, and calculates the optical power in the FPGA based on the characteristics of the photodetector and calibration data. The optical power corresponding to the N digital signals is calculated. If the optical power of any channel is lower than the preset optical power threshold, it is determined that the main laser of that channel has failed. Optical switch signals for the main laser and its corresponding backup laser are generated, the main laser is turned off, the corresponding backup laser is started, and the backup laser is defined as the main laser. The failed main laser is defined as the backup laser.

[0046] The temperature control adjustment module includes a semiconductor cooler installed on one side of the REC laser array and individual heaters installed at each of the 2N REC lasers. The temperature control adjustment module processes the N first electrical signals, completes ADC conversion through MCU programming instructions, and the digital value read in the ADC register reflects the current corresponding to the first electrical signal. The optical power corresponding to the N different wavelength signal lights is calculated by formula. If the optical power of any one of them is lower than the preset optical power threshold, it is determined that the main laser corresponding to that wavelength has failed, a timer is started, and the semiconductor cooler is turned on to cool the REC laser array as a whole. When the timer exceeds the preset switching time threshold, if the optical power of the laser of that wavelength still has not reached the preset optical power threshold, the individual heater of the backup laser corresponding to the failed main laser is turned on to heat the backup laser individually until the optical power of the laser of that wavelength reaches the preset optical power threshold.

[0047] Figure 1 This is a schematic diagram of the backup-type high-density monolithic integrated multi-channel REC laser of the present invention. Figure 1 As shown, the backup high-density monolithic integrated multi-channel REC laser includes a REC laser array, a wavelength division multiplexing combiner / demultiplexer, an EDFA, a coupler, a photodetector, a channel switching module, and a temperature control adjustment module.

[0048] The REC laser array includes 2N REC lasers, which are divided into N groups of two. In each group, one of the two REC lasers is the main laser used during normal operation, and the other is the backup output laser activated when the main laser fails. When the main laser is working normally, the backup laser is kept in a cooled state.

[0049] A wavelength division multiplexing (WDM) multiplexer receives N signals from the laser array and generates a multiplexed optical signal. Since the output power of the REC laser is not high, the optical signal needs to be amplified by an erbium-doped fiber amplifier (EDFA) for more accurate measurement. The amplified optical signal is then split into two parts at a 1:1 ratio by a coupler and decomposed into N optical signals by a WDM multiplexer. These signals are then fed into two photodetectors to measure the optical power of the signals and convert them into corresponding electrical signals. The measurement results are then fed back to the two modules.

[0050] The channel switching module includes a preamplifier circuit, an A / D conversion circuit, an FPGA, an optical switch driver circuit, and a 1×2N optical switch. It monitors the status of the main laser and the backup laser, and controls the optical switch to quickly switch channels when the main laser fails. After receiving the electrical signal output from photodetector 2, the channel switching module amplifies and filters the signal before sending it to the A / D converter for analog-to-digital conversion. The resulting digital signal is then sent to the FPGA for demodulation and calculation, and the output signal is sent to the driver circuit. The optical switch driver circuit amplifies the decoded signal to convert it into a signal capable of driving the optical switch. When the Nth main laser fails, the optical switch receives the drive signal and performs channel switching, shutting down the failed main laser and activating the corresponding Nth backup laser, thus completing the switching operation.

[0051] Both the optical switch driver circuit and the semiconductor laser generate a significant amount of heat during operation, which can easily affect their normal operation, especially since the laser itself is highly sensitive to temperature. When the temperature changes, the output wavelength of the REC-based laser array also changes drastically, making rapid stabilization after channel switching impossible. Furthermore, when used in high-density monolithically integrated multi-channel lasers, all lasers on the chip are operating simultaneously, leading to significant heat accumulation within the lasers. The small integrated volume and the spacing between lasers make heat dissipation difficult, causing the chip temperature to rise rapidly in a short time. This results in a decrease in the output power of the REC laser, affecting channel switching efficiency. To ensure the wavelength stability of the laser array after channel switching and maintain a short channel switching time, a temperature control adjustment module is added to achieve output wavelength locking and efficient channel switching.

[0052] The temperature control module includes a microcontroller unit (MCU), a temperature control circuit, and a temperature regulation unit. The temperature regulation unit includes a semiconductor cooler and 2N individual heaters corresponding to the laser unit. The temperature control module implements temperature control as follows: Figure 3 As shown, the MCU collects and processes the output optical power values ​​of the N channels of photodetector 1, calculates the difference between the current optical power of the N channels and the reference optical power output when the laser is working normally, and then compares it with a preset threshold. If the threshold is exceeded, it indicates that the laser has malfunctioned. At this time, the channel switching module starts the switching operation between the main and backup lasers, the MCU enables the timing function and resets the timer. An acceptable channel switching time is preset. Before this time is exceeded, the semiconductor cooler coupled to the laser array is used to cool down and establish a global temperature. If the laser fails to restore normal power output and the preset time is exceeded, the MCU adjusts the resistive heater of the adjacent corresponding laser through the temperature control circuit to increase the local temperature of the individual laser to achieve precise control. The MCU continuously samples the output optical power until the channel switching module completes the switching operation and the temperature control circuit compensates for the wavelength drift of the laser and restores normal power output. After this, the timer stops and the result is output to the external display screen of the MCU. This time data is the complete time required for a set of main / backup channel lasers to switch.

[0053] For ease of explanation, this embodiment only uses a 2-backup 16-channel REC laser for technical solution description. In practical applications, the high-density monolithic integrated multi-channel REC laser of this embodiment can select any number of backup REC laser arrays as needed. When the number of channels in the REC laser array used is not 16, only the number of structural components of other devices needs to be adjusted adaptively, such as the number of channels in the photodetector and the number of output fibers in the optical switch. The control principle of the laser remains the same.

[0054] In this embodiment, there are a total of 16 REC lasers, divided into 8 groups. Each group contains a main laser and a backup laser. The backup laser is kept off when the main laser is working normally. The laser array wavelength ranges from 1546.8nm to 1560.08nm.

[0055] Figure 2 This is a schematic diagram of a 2-backup 16-channel laser array based on the Reconstructed Equivalent Chirp (REC) technique. In semiconductor laser structures, the REC technique is used to change the channel wavelength by only changing the sampling photomask period without changing the uniform seed grating period, thus realizing a high-density monolithically integrated laser array.

[0056] like Figure 4As shown, when the main laser 1 fails, the 16-channel photodetector feeds back the output optical power detected by channel 1 to the channel switching module. After receiving the electrical signal output by photodetector 2, the channel switching module amplifies and filters the signal before sending it to the A / D converter for analog-to-digital conversion. The resulting digital signal is then sent to the FPGA for demodulation and calculation. A comparison reveals that the power is less than the set normal operating power range, indicating a channel failure. The FPGA module initiates channel switching, decoding the signal of the backup channel 9 (which replaces channel 1) into a drive signal. The optical switch drive circuit amplifies the decoded signal, converting it into a signal capable of driving the optical switch, thus controlling the 1×16 optical switch. The 1×16 optical switch completes the switching from channel 1 to channel 9. The signal entering from the input terminal is output from the ninth output terminal, thereby activating the backup laser 1 and completing the channel switching process.

[0057] After receiving the electrical signal output by photodetector 1, the MCU collects the output optical power value, calculates the difference between the current optical power of the 16 channels and the reference optical power of -10dBm when the laser is operating normally, and compares it with a preset threshold. If the optical power difference of channel 1 exceeds the threshold, the MCU activates the timing function, resets the timer, and starts the temperature control circuit to adjust the TEC coupled to the laser array for cooling, establishing a global temperature. The system's preset channel switching time is 500ns. During this time, backup laser 1 fails to reach the -10dBm power output. The MCU determines that, based on TEC cooling, the temperature control circuit adjusts the resistive heater installed on backup laser 1 to increase its local temperature for precise control. During this period, the MCU continuously samples the output optical power. After 350ns, it detects that the output optical power of channel 9 is -10.332dBm, within the threshold range for normal laser operation. The timer stops, and the result is output to the MCU's external display screen. Therefore, the complete time required for the main / backup laser to switch is 850ns. Figure 5 As shown, the output characteristics of the REC laser array chip returned to normal, ensuring the continuous operation capability and output stability of the 2 backup 16-channel REC lasers.

[0058] In addition, by employing REC integrated laser array technology, which can precisely control wavelength spacing, the grating structure of semiconductor lasers can be optimized to obtain narrow linewidth output, thereby achieving backup of high-density monolithic integrated multi-channel narrow linewidth lasers.

[0059] In summary, the 2-backup 16-channel REC laser described in this embodiment adopts a backup structure. When a channel fails, the system can automatically and quickly switch over without affecting the normal operation of the entire system. Furthermore, the temperature control adjustment module ensures the output stability after switching, which can meet the needs of application fields with high requirements for the reliability of laser systems.

[0060] The above description, in conjunction with specific embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such deductions or substitutions should be considered within the scope of protection of the present invention.

Claims

1. A backup high-density monolithic multi-channel REC laser, characterized in that, The multi-channel REC laser includes an REC laser array, a wavelength division multiplexing combiner, an EDFA amplifier, a coupler, a first wavelength division multiplexing demultiplexer, a second wavelength division multiplexing demultiplexer, a first photodetector, a second photodetector, a channel switching module and a temperature control adjustment module; The REC laser array includes 2N REC lasers, which are divided into N groups in two groups each time, one of the two REC lasers in each group is a main laser used in normal operation, and the other is a backup laser used when the main laser fails; N is a positive integer greater than 1; The wavelength division multiplexing combiner is used to couple N optical signals of different channel wavelengths output simultaneously by the REC laser array to generate a multiplexed optical signal, which is amplified by the EDFA amplifier; The coupler performs power distribution on the amplified optical multiplexed signal from the EDFA amplifier at a ratio of 1:1, and the two optical multiplexed signals are respectively decomposed into N optical signals through the first wavelength division multiplexing demultiplexer and the second wavelength division multiplexing demultiplexer; the first photodetector converts the N optical signals output by the first wavelength division multiplexing demultiplexer into N first electrical signals and sends them to the temperature control adjustment module; and the second photodetector converts the N optical signals output by the second wavelength division multiplexing demultiplexer into N second electrical signals and sends them to the channel switching module; The channel switching module amplifies the N second electrical signals, converts the amplified second electrical signals into corresponding digital signals, calculates the optical power corresponding to the N digital signals, and if the optical power of any one of the N digital signals is lower than a preset optical power threshold, it is determined that the main laser of the channel corresponding to the digital signal fails, an optical switch signal of the main laser and the corresponding backup laser is generated, the main laser is turned off, the corresponding backup laser is started, and the backup laser is defined as the main laser, and the failed main laser is defined as the backup laser; The temperature control adjustment module includes a semiconductor refrigerator installed on one side of the REC laser array and a separate heater installed one-to-one at the 2N REC lasers; the temperature control adjustment module processes the N first electrical signals, calculates the optical power corresponding to the N different wavelength signals, and if the optical power of any one of the N different wavelength signals is lower than a preset optical power threshold, it is determined that the main laser corresponding to the wavelength fails, a timer is started, and the semiconductor refrigerator is turned on to cool the REC laser array as a whole; when the timer exceeds a preset switching time threshold and the optical power of the laser corresponding to the wavelength still does not reach the preset optical power threshold, the separate heater of the backup laser corresponding to the failed main laser is turned on to heat the backup laser, until the optical power of the laser corresponding to the wavelength reaches the preset optical power threshold.

2. The backup high-density monolithic multi-channel REC laser of claim 1, wherein, The channel switching module includes a preamplifier circuit, an A / D conversion circuit, an FPGA unit, an optical switch driving circuit and a 1*2N optical switch connected in sequence; The preamplifier circuit amplifies the N second electrical signals and sends them to the A / D conversion circuit to convert them into corresponding digital signals; The preamplifier circuit amplifies the N second electrical signals and sends them to the A / D conversion circuit to convert them into corresponding digital signals; The FPGA unit processes the digital signal output by the A / D conversion circuit, calculates the optical power corresponding to the N digital signals, and if the optical power of any one of the N signals is lower than a preset optical power threshold, determines that the main laser of the signal has failed, generates an optical switch signal of the main laser and its corresponding backup laser, and sends the signal to the optical switch driving circuit; meanwhile, the backup laser is defined as the main laser, and the failed main laser is defined as the backup laser. The input end of the 1*2N optical switch is connected with the output end of the optical switch driving circuit, the 1*2N optical switch has 2N output ends, and is connected with 2N REC lasers respectively; the optical switch driving circuit closes the main laser according to the received optical switch signal and starts the corresponding backup laser.

3. The backup high-density monolithic multi-channel REC laser of claim 2, wherein, When the FPGA unit switches the channel, the backup channel signal enabled instead of the main channel is translated into a driving signal, the optical switch is controlled through the driving circuit, and finally the current state information of the optical switch is fed back to the FPGA, the FPGA compares whether the switched channel signals are the same, if the same, the channel switching is successful; if not, the channel switching fails.

4. The backup high-density monolithic multi-channel REC laser of claim 2, wherein, The 1*2N optical switch has 1 input optical fiber and 2N output optical fibers, and the 2N REC lasers are connected with the 2N output optical fibers one by one; the driving voltage range of the 1*2 optical switch is 5V-6V, when the optical switch is added with driving voltage, the optical switch is in the off state, and when the optical switch is not added with voltage or added with very small voltage, the optical switch is in the on state.

5. The backup high-density monolithic multi-channel REC laser of claim 1, wherein, The temperature control adjustment module comprises an MCU unit, a temperature control circuit and a temperature adjustment unit connected in sequence; The temperature adjustment unit comprises a semiconductor refrigerator installed on one side of the REC laser array and a separate heater installed one by one at the 2N REC lasers; The MCU unit comprises a signal judgment component, a timing component, a backup laser management component, a refrigeration component and a heating component; The signal judgment component processes the N first electrical signals, calculates the optical power corresponding to the N different wavelength signal lights, and if the optical power of any one of the N signals is lower than a preset optical power threshold, determines that the main laser corresponding to the wavelength has failed, generates a timing signal and sends it to the timing component to start timing, and triggers the refrigeration component to generate a cooling start signal to the temperature control circuit to start the semiconductor refrigerator until the optical power of the laser corresponding to the wavelength reaches the preset optical power threshold, stops timing and clears the timing; The signal judging component continuously judges the optical power of the optical signal corresponding to the wavelength. When the recording time length of the timing component exceeds the preset switching time length threshold, and the optical power of the laser corresponding to the wavelength has not reached the preset optical power threshold, a heating start signal is generated by the heating component to the temperature control circuit to start the individual heater of the standby laser corresponding to the semi-failed main laser, and the standby laser is individually heated until the optical power of the laser corresponding to the wavelength reaches the preset optical power threshold, the timing is stopped, the timing is emptied, and the standby laser management component is triggered to update the standby laser list, and the standby laser is defined as the main laser, and the failed main laser is defined as the standby laser.

6. The backup high-density monolithic multi-channel REC laser of claim 5, wherein, The channel switching module periodically sends the standby laser list stored by itself to the MCU unit, and the standby laser lists stored in the two are compared by the MCU unit. If the comparison is wrong, an alarm signal is generated.

7. The backup high-density monolithic multi-channel REC laser of claim 5, wherein, The temperature control adjustment module further comprises a timing display component. The timing display component is used to display the complete time length of the laser switching.

8. The backup high-density monolithic multi-channel REC laser of claim 1, wherein, The semiconductor refrigerator adopts a thermoelectric refrigerator coupled to the REC laser array.

9. The backup high-density monolithic multi-channel REC laser of claim 1, wherein, The individual heater is a resistance heater installed on the laser.

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