Wavelength and power adaptive compensation method and system of DBR tunable laser

Abstract

The invention discloses a wavelength and power adaptive compensation method and system for a DBR tunable laser, and relates to the technical field of tunable semiconductor lasers, and the method comprises the steps: controlling the operation of a laser through a constant current source, and collecting the wavelength and output power of the laser; performing signal processing on the wavelength and the output power; carrying out limiting processing on the wavelength accuracy and the power reference point of the laser; and adaptively compensating the output power and the wavelength of the laser based on the limiting processing. The problem of wavelength and power cross influence caused by inner loop feedback is solved, the structure is simple, output signals of the two monitoring units can be processed at the same time, and implementation is easy; a fuzzy PID control algorithm is adopted to monitor and stabilize power based on the power monitoring loop, a wavelength calibration algorithm is designed based on the wavelength monitoring loop to monitor and stabilize wavelength, and high-precision synchronous stabilization of the wavelength and the power of the laser is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of tunable semiconductor lasers, in particular to a wavelength and power adaptive compensation method and system for a DBR tunable laser. Background Art

[0002] Tunable semiconductor lasers are widely used in fiber-optic communications, spectral analysis, and fiber-optic sensing due to their small size, light weight, long life, and flexible wavelength switching. Distributed Bragg reflector (DBR) lasers have the advantages of compact structure and high mechanical stability. They include three regions: active region, phase region, and grating region. Current needs to be injected into the three regions simultaneously to control the wavelength and power. However, the wavelength tuning range is generally only 10nm. In order to expand the wavelength tuning range, researchers have improved the three-section structure of distributed Bragg reflector DBR lasers and obtained DBR lasers with different structures, such as sampled grating SG-DBR lasers, modulated grating Y-branch MG-Y lasers, and digital sampling DS-D BR lasers, the improved DBR lasers have a larger wavelength tuning range, the wavelength switching speed can reach the nanosecond level, and the cost is relatively low, with a wide range of application scenarios; however, although these improved DBR lasers have made significant progress in wavelength tuning range and switching speed, they have also brought new challenges. For example, the control complexity of the multi-segment structure has increased, and the mutual influence between the segments has become more significant, making it more difficult to accurately control the wavelength and power; the high sensitivity of semiconductor lasers makes the output stability easily affected by external factors such as temperature and current fluctuations, resulting in wavelength drift and power fluctuations, so it is necessary to compensate by adjusting the wavelength control signal and power control signal of the DBR laser.

[0003] However, the current common solutions have many disadvantages, including: due to the high sensitivity of semiconductor lasers, the corresponding output stability is prone to fluctuations. The existing compensation methods are mainly divided into inner-loop feedback and outer-loop feedback. Although the inner-loop feedback method has the advantages of high integration of the control system structure and simplicity and effectiveness, it also introduces the cross-influence problem of wavelength and power, making precise control more complicated; secondly, most of the existing compensation technologies rely on preset lookup tables or fixed compensation algorithms, lack the ability to dynamically adapt to the real-time state of the laser, and it is difficult to cope with the performance changes and aging problems of the laser during long-term use. Summary of the invention

[0004] In view of the fact that when compensating for the wavelength and power of a DBR laser, the inner loop feedback method used in the prior art has the advantages of high integration of the control system structure and simplicity and effectiveness, but also introduces the problem of cross-influence of wavelength and power, making precise control more complicated, and most compensation technologies rely on preset lookup tables or fixed compensation algorithms, lacking the ability to dynamically adapt to the real-time state of the laser, and the like, the present invention is proposed.

[0005] Therefore, the problem to be solved by the present invention is how to provide a method for adaptive compensation of wavelength and power of a DBR tunable laser. By constructing a wavelength inner loop feedback loop and a power inner loop feedback loop, a photodetector and a frequency discriminator are used to synchronously monitor the wavelength and power. A laser power control algorithm based on fuzzy proportional integral differential PID and a wavelength calibration algorithm based on current adaptive compensation are proposed to adjust the wavelength and power. The multi-channel constant current sources of the system are independently and comprehensively controlled by a main controller, and the monitor and the laser are integrated into a butterfly packaging tube. The problem of cross-influence of wavelength and power of the DBR laser is solved, and the method with poor control effect and complex circuit in the prior art is overcome.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] In a first aspect, an embodiment of the present invention provides a wavelength and power adaptive compensation method for a DBR tunable laser, which includes using a constant current source to control the operation of the laser, collecting the wavelength and output power of the laser; performing signal processing on the wavelength and the output power; limiting the wavelength accuracy and power reference point of the laser; and adaptively compensating the output power and wavelength of the laser based on the limiting processing.

[0008] As a preferred solution of the wavelength and power adaptive compensation method of the DBR tunable laser described in the present invention, wherein: the operation of the laser is controlled by using a constant current source, which is to use a main controller to query an initial wavelength current lookup table, send address bits and data bits to a constant current source chip, so that multiple constant current sources output a specified current, thereby causing the laser to generate laser light; the wavelength and output power of the laser are collected by sending the laser to a wavelength monitor and a power monitor at the same time through a beam splitter, detecting the wavelength and power of the laser, and obtaining two output signals related to the wavelength drift and output power fluctuation of the laser.

[0009] As a preferred solution of the wavelength and power adaptive compensation method of the DBR tunable laser described in the present invention, the signal processing includes: using a transimpedance amplifier to convert the current signal output by the photodetector into a current-voltage conversion, and the converted voltage signal cannot exceed the power supply voltage of the analog-to-digital converter; filtering and noise reduction processing is performed on the output signal to stabilize the amplitude; the limiting processing includes setting the wavelength accuracy of the laser tuning and setting the power reference point of the full wavelength range.

[0010] As a preferred solution of the wavelength and power adaptive compensation method of the DBR tunable laser of the present invention, wherein: the adaptive compensation includes adaptive compensation of the output power of the laser based on the fuzzy PID control algorithm and adaptive compensation of the wavelength of the laser based on the wavelength calibration algorithm; the adaptive compensation of the output power of the laser based on the fuzzy PID control algorithm includes the following steps: using the power inner loop feedback loop to achieve power stability of the laser, considering that the signal processor processes data in discrete form, using the fuzzy PID control algorithm to stabilize the power, and the calculation formula of the PID adjustment means of the power control current is as follows:

[0011]

[0012] Where u(k) is the control signal sent by the signal processor; K P is the proportional coefficient, where the fuzzy PID coefficient includes the proportional coefficient K P , integral coefficient K I and the differential coefficient K D ; e(k) is the difference between the set standard power voltage threshold and the power feedback voltage collected for the kth time; K I is the integral coefficient; k is the number of feedback iterations; e(j) is the difference between the set standard power voltage threshold and the power feedback voltage collected for the jth time; K D is the differential coefficient.

[0013] As a preferred solution of the wavelength and power adaptive compensation method of the DBR tunable laser of the present invention, the calculation formula of the fuzzy PID coefficient is as follows:

[0014] K P =K P0 +ΔK P

[0015] K I =K I0 +ΔK I

[0016] K D =K D0 +ΔK D

[0017] Among them, K P is the proportionality coefficient; K P0 is the initial value of the proportionality coefficient; ΔK P is the fuzzy coefficient; K I is the integral coefficient; K I0 is the initial value of the integral coefficient; ΔK I is the fuzzy coefficient; K D is the differential coefficient; K D0 is the initial value of the differential coefficient; ΔK D is the fuzzy coefficient; the adaptive compensation of the wavelength of the laser based on the wavelength calibration algorithm includes the following steps: inputting part of the laser into the discriminator and the photodetector to obtain a wavelength deviation signal; using the fine tuning area of ​​the laser to perform current compensation, wherein the current compensation coefficient increases as the current decreases.

[0018] As a preferred solution of the wavelength and power adaptive compensation method of the DBR tunable laser described in the present invention, the wavelength and power adaptive compensation system of the DBR tunable laser includes a laser chip, a collimating lens, an optical isolator, a beam splitter, a focusing lens, a wavelength monitor, a power monitor, a transimpedance low noise amplifier, an analog-to-digital converter, a signal processor and a constant current source module; the wavelength monitoring circuit includes a frequency discriminator, a photoelectric detector PD, an analog-to-digital converter, a signal processor and a constant current source; the power monitoring circuit includes a photoelectric detector PD, an analog-to-digital converter, a signal processor and a constant current source; the output end of the laser chip is respectively connected to the input end of the wavelength monitor and the input end of the power monitor through the beam splitter; the output end of the wavelength monitor and the output end of the power monitor are connected to the input end of the low noise amplifier module to obtain wavelength and power feedback signals, the feedback signals are processed by the signal processor, and the compensation signals of the wavelength and power are calculated by the fuzzy PID control algorithm and the wavelength calibration algorithm, so as to control the constant current source and adjust the current.

[0019] As a preferred solution of the wavelength and power adaptive compensation method of the DBR tunable laser described in the present invention, wherein: a wavelength monitor, a power monitor, a laser chip, a collimating lens, an optical isolator, a beam splitter and a focusing lens are integrated in a butterfly-shaped packaging tube; the laser chip is a DBR type semiconductor, including a grating region, a phase region, a gain region and an optical amplification region; the discriminator is an FP standard tool, a gas absorption cell or a grating; and a TEC cooler is provided in the butterfly-shaped packaging tube for stabilizing the temperature of the laser chip and the optical device.

[0020] In the second aspect, in order to further solve the safety problems existing in laser compensation, the present invention provides a wavelength and power adaptive compensation system for a DBR tunable laser, which includes: a data acquisition module, which is used to control the laser to generate laser light using a constant current source, and use a beam splitter to send the laser to a wavelength monitor and a power monitor at the same time, detect the wavelength and output power of the laser, and obtain two output signals related to the wavelength drift and output power fluctuation of the laser; a data processing module, which is used to limit the amplitude, reduce noise and stabilize the amplitude of the wavelength and output power, set requirements for the wavelength accuracy of laser tuning, and set a power reference point in the full wavelength range; an adaptive compensation module, which is used to adaptively compensate the output power of the laser based on a fuzzy PID control algorithm, and adaptively compensate the wavelength of the laser based on a wavelength calibration algorithm, so as to achieve synchronous stabilization of the laser wavelength and output power.

[0021] In a third aspect, an embodiment of the present invention provides a computer device, comprising a memory and a processor, wherein the memory stores a computer program, wherein: when the computer program is executed by the processor, any step of the wavelength and power adaptive compensation method of a DBR tunable laser as described in the first aspect of the present invention is implemented.

[0022] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein: when the computer program is executed by a processor, any step of the wavelength and power adaptive compensation method for a DBR tunable laser as described in the first aspect of the present invention is implemented.

[0023] The beneficial effects of the present invention are as follows: the present invention proposes a wavelength and power adaptive compensation method for a DBR tunable laser, which can solve the problem of wavelength and power cross-influence caused by inner loop feedback, and ensure the simultaneous stability of wavelength and power; the adaptive compensation system has a simple structure, can simultaneously limit the amplitude, stabilize the amplitude and perform noise reduction filtering processing on the output signals of two monitoring units, and is easy to implement; the adaptive compensation system overcomes the defect of low control accuracy of laser wavelength stability in the prior art, adopts a fuzzy PID control algorithm based on a power monitoring loop to monitor and stabilize the power, and designs a wavelength calibration algorithm based on a wavelength monitoring loop to monitor and stabilize the wavelength, thereby achieving high-precision synchronous stability of laser wavelength and power. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. 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 creative work. Among them:

[0025] Figure 1 Schematic diagram of the wavelength and power adaptive compensation system of the DBR tunable laser in Example 1.

[0026] Figure 2 This is a diagram of the interior of the DBR tunable laser butterfly package in Example 1.

[0027] Figure 3 This is a relationship diagram between the MG-Y laser power and the power feedback current in Example 1.

[0028] Figure 4 This is the principle block diagram of the fuzzy PID control algorithm in Example 1.

[0029] Figure 5 Schematic diagram of the triangle membership function in Example 1.

[0030] Figure 6 This is a flow chart for implementing the wavelength calibration algorithm in Example 1.

[0031] Figure 7 is the proportionality coefficient K in Example 2 P Schematic diagram of the fuzzy rule table.

[0032] Figure 8 is the integral coefficient K in Example 2 I Schematic diagram of the fuzzy rule table.

[0033] Fig. 9 is the differential coefficient K in Example 2 D Schematic diagram of the fuzzy rule table.

[0034] Fig.10 is the phase zone current I when different reflector current combinations are used in Example 2 phase Tuning characteristics diagram.

[0035] Fig.11 This is a comparison chart of the adaptive compensation results of the laser output power in Example 2.

[0036] Fig.12 This is a diagram showing the adaptive compensation results of the laser wavelength before calibration in Example 2.

[0037] Fig.13 This is a diagram showing the adaptive compensation results of the laser wavelength after calibration in Example 2. DETAILED DESCRIPTION

[0038] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0039] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0040] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0041] Example 1

[0042] Reference Figure 1 to Figure 6 , which is the first embodiment of the present invention, provides a wavelength and power adaptive compensation method for a DBR tunable laser, comprising the following steps:

[0043] S1: Use a constant current source to control the operation of the laser and collect the wavelength and output power of the laser.

[0044] Preferably, Figure 1 The figure shows a schematic diagram of the wavelength and power adaptive compensation system of the DBR tunable laser proposed in the present invention. The wavelength and power adaptive compensation system of the DBR tunable laser includes a laser chip, a collimating lens, an optical isolator, a beam splitter, a focusing lens, a wavelength monitor, a power monitor, a transimpedance low noise amplifier, an analog-to-digital converter, a signal processor and a constant current source module.

[0045] Specifically, the wavelength monitoring circuit includes a frequency discriminator, a photoelectric detector PD, an analog-to-digital converter, a signal processor and a constant current source.

[0046] Specifically, the power monitoring circuit includes a photodetector PD, an analog-to-digital converter, a signal processor and a constant current source.

[0047] Furthermore, the output end of the laser chip is connected to the wavelength monitor input end and the power monitor input end respectively through a beam splitter.

[0048] Furthermore, the output end of the wavelength monitor and the output end of the power monitor are connected to the input end of the low-noise amplifier module to obtain wavelength and power feedback signals, and the feedback signals are processed by a signal processor. The compensation signals of wavelength and power are calculated by a fuzzy PID algorithm and a wavelength calibration algorithm, thereby controlling the constant current source and adjusting the current.

[0049] Furthermore, a wavelength monitor, a power monitor, a laser chip, a collimating lens, an optical isolator, a beam splitter and a focusing lens are integrated in a butterfly-shaped packaging tube.

[0050] Specifically, the laser chip is a DBR type semiconductor, including a grating region, a phase region, a gain region and a light amplification region.

[0051] Specifically, the frequency discriminator is a FP etalon, a gas absorption cell or a grating.

[0052] Specifically, the butterfly-shaped packaging tube is equipped with a TEC cooler to stabilize the temperature of the laser chip and optical devices and ensure the effect of laser wavelength and power compensation.

[0053] Preferably, the operation of the laser is controlled by using a constant current source to query an initial wavelength current lookup table using a main controller, send address bits and data bits to a constant current source chip, and make multiple constant current sources output a specified current, thereby making the laser generate laser light.

[0054] Specifically, the constant current source is composed of five current chips. The current range and accuracy are set by external resistors. The five currents generated include the left reflector current I left , right reflector current I right , Phase zone current I phase , gain region current I gain And the optical amplifier current I SOA .

[0055] Furthermore, the left reflector current I left and the right reflector current I right The overlap position of the reflection peaks is controlled by the vernier effect to achieve coarse wavelength adjustment.

[0056] Furthermore, the phase zone current I phase It is possible to adjust the delay of light propagating in the phase section, providing a fine tuning range of wavelength of around 0.3nm.

[0057] Furthermore, when the laser wavelength is selected, the current I gain and the optical amplifier current I SOA Adjust to change the output power of the laser. In practical applications, the gain region current I is usually fixed. gain , only the current I in the optical amplifier area is changed SOA To adjust the power.

[0058] Preferably, the wavelength and output power of the laser are collected by simultaneously sending the laser to a wavelength monitor and a power monitor through a beam splitter, detecting the wavelength and power of the laser to obtain two output signals related to the wavelength drift and output power fluctuation of the laser.

[0059] Specifically, Figure 2 The figure shows the internal structure of the butterfly package of the DBR tunable laser, which integrates the optical beam splitter, FP etalon, photodetector and laser chip on the same carrier; the frequency interval of the FP etalon is set to 50GHz, and the peak-to-peak wavelength of the transmission corresponds to the ITU standard wavelength; when the laser is tuned to the fixed channel of the FP etalon, the corresponding wavelength deviation can be detected; the power monitor converts the output power into an inverted reference current I PD.ref , the linear fitting degree reaches 0.99983, and the characteristic curve of MG-Y laser power and power feedback current is as follows Figure 3 As shown, by inverting the reference current I PD.ref The corresponding power fluctuation amount can be detected.

[0060] Specifically, by using five constant current sources to control different areas of the laser, including the left reflector, the right reflector, the phase area, the gain area and the optical amplification area, coarse and fine tuning of the wavelength and precise adjustment of the power can be achieved, thereby improving the tuning accuracy and flexibility of the laser.

[0061] S2: Perform signal processing on wavelength and output power.

[0062] Preferably, the signal processing includes: using a transimpedance amplifier to perform current-to-voltage conversion on the current signal output by the photodetector, the converted voltage signal cannot exceed the supply voltage of the analog-to-digital converter, and the amplification factor depends on the situation.

[0063] The output signal is filtered and denoised to stabilize the amplitude.

[0064] Furthermore, since the power supply voltage of the analog-to-digital converter is 2.5V, the feedback voltage input to the analog-to-digital converter must not exceed 2.5V.

[0065] Furthermore, resistors are used to convert the current signals output by the wavelength monitor and the power monitor into voltage signals, and a signal conditioning circuit is used to amplify and filter the voltage to keep the amplitude stable and meet the requirements of the analog-to-digital converter input voltage range.

[0066] Specifically, by using a transimpedance amplifier to perform current-to-voltage conversion and filtering and noise reduction processing, not only the signal-to-noise ratio of the signal is improved, but also the signal amplitude is ensured to be stable and meet the input requirements of the analog-to-digital converter, effectively avoiding signal saturation and distortion problems.

[0067] S3: Define the wavelength accuracy and power reference point of the laser.

[0068] Preferably, the definition process includes setting the wavelength accuracy of laser tuning and setting the power reference point of the full wavelength range, so as to perform subsequent adaptive compensation of wavelength and output power.

[0069] Specifically, by setting the wavelength accuracy and power reference point, the accuracy and efficiency of compensation can be improved, providing a reliable reference standard for achieving high-precision wavelength and power control.

[0070] S4: Adaptively compensate the output power and wavelength of the laser based on the limiting process.

[0071] Preferably, the adaptive compensation includes adaptively compensating the output power of the laser based on a fuzzy PID control algorithm and adaptively compensating the wavelength of the laser based on a wavelength calibration algorithm.

[0072] Specifically, the adaptive compensation of the output power of the laser based on the fuzzy PID control algorithm includes the following steps: using the power inner loop feedback loop to achieve the power stability of the laser, considering that the signal processor processes data in discrete form, using the fuzzy PID control algorithm to stabilize the power, the calculation formula of the PID adjustment means of the power control current is as follows:

[0073]

[0074] Among them, u(k) is the control signal sent by the signal processor, which directly determines the current I in the optical amplifier area. SOA The compensation amount; K P is the proportional coefficient; e(k) is the difference between the set standard power voltage threshold and the power feedback voltage collected for the kth time, that is, the error collected by the system for the kth time. The power control current is dynamically adjusted according to the deviation e(k) and the fuzzy PID coefficient under different feedback cycle times, thereby achieving the effect of adaptive compensation. The fuzzy PID coefficient includes the proportional coefficient K P , integral coefficient K I and the differential coefficient K D ; K I is the integral coefficient; k is the number of feedback iterations; e(j) is the difference between the set standard power voltage threshold and the power feedback voltage collected for the jth time; K D is the differential coefficient.

[0075] Further, such as Figure 4 The figure shows the principle block diagram of the fuzzy PID control algorithm, in which the process of determining the fuzzy coefficient includes fuzzification, establishing fuzzy rules and clarifying, so that the overall PID coefficient changes adaptively to achieve the optimal control effect. The process of determining the fuzzy coefficient includes the following steps: Figure 5 The triangle membership function is shown in Figure 2. By using the triangle membership function to calculate the proportional coefficient K P , integral coefficient K I and the differential coefficient K D To fuzzify.

[0076] The domain intervals of the error e(k) and the deviation change rate ec(k) of the power feedback voltage collected by the kth system are set to [-6, 6], corresponding to 7 fuzzy subsets, including deviation value negative strong NB, deviation value negative medium NM, deviation value negative weak NS, zero deviation ZO, deviation value positive weak PS, deviation value positive medium PM and deviation value positive strong PB, corresponding to -6, -4, -2, 0, 2, 4 and 6 respectively. The output of the fuzzy PID control algorithm, that is, the fuzzy coefficient ΔK P , fuzzy coefficient ΔK I and the fuzziness coefficient ΔK D The same domain interval and fuzzy subsets are used in both.

[0077] Based on the empirical method and trial and error method, the fuzzy rule table is constructed and the proportional coefficient K is obtained. P , integral coefficient K I and the differential coefficient K D The membership degree of the fuzzy subset.

[0078] According to the fuzzy rule table, the output of the fuzzy PID control algorithm, that is, the fuzzy coefficient ΔK P , fuzzy coefficient ΔK I and the fuzziness coefficient ΔK D After the clarification process is performed, the proportional coefficient K P , integral coefficient K I and the differential coefficient K D The output quantity of membership calculation of fuzzy subsets.

[0079] Specifically, the calculation formula of the fuzzy PID coefficient is as follows:

[0080] K P =K P0 +ΔK P

[0081] K I =K I0 +ΔK I

[0082] K D =K D0 +ΔK D

[0083] Among them, K P is the proportionality coefficient; K P0 is the initial value of the proportionality coefficient, where the initial value is selected by orthogonal test method; ΔK P is the fuzzy coefficient; K I is the integral coefficient; K I0 is the initial value of the integral coefficient; ΔK I is the fuzzy coefficient; K Dis the differential coefficient; K D0 is the initial value of the differential coefficient; ΔK D is the fuzzy coefficient.

[0084] Specifically, since the output power drift of the DBR tunable laser will increase over time, in order to improve the long-term output stability of the laser, it is necessary to dynamically adjust the proportional coefficient, integral coefficient and differential coefficient of the fuzzy PID control algorithm, so fuzzy PID control is selected.

[0085] Furthermore, due to the thermal effect of SOA, the wavelength will drift while compensating the power, which will cause the cross-influence problem of wavelength and power.

[0086] Specifically, adaptively compensating the wavelength of the laser based on the wavelength calibration algorithm includes the following steps: inputting part of the laser into a frequency discriminator and a photoelectric detector to obtain a wavelength deviation signal.

[0087] The fine tuning area of ​​the laser is used for current compensation, where the current compensation coefficient increases as the current decreases. Therefore, data needs to be collected in advance for determination to prevent over-compensation and under-compensation.

[0088] Further, such as Figure 6 The figure shows the implementation process of the wavelength calibration algorithm, which includes the following steps: determining the standard output wavelength of the laser.

[0089] Determine a set of left reflector currents I left and the right reflector current I right , so that the side mode suppression ratio of the laser output corresponding to the wavelength is maximized, and the left reflector current I is fixed left , right reflector current I right and gain region current I gain , set the phase zone current I phase After scanning, multiple phase zone currents I with different slopes are obtained. phase linear tuning region.

[0090] A region with a wavelength coverage range greater than or equal to 0.2 nm and the highest wavelength accuracy is selected, and the corresponding region is specified as a wavelength calibration data segment.

[0091] According to the optical amplifier current I SOA Scan in steps of 1 mA until the laser output power range is covered.

[0092] Scanning light amplification area current I SOA At the same time, the phase zone current I is adjusted according to the compensation data segment phase , get the calibrated wavelength, make the calibrated wavelength infinitely close to the standard output wavelength, and get the optical amplifier current ISOA -Phase zone current I phase Lookup table.

[0093] The optical amplifier current I in the lookup table SOA and phase zone current I phase After piecewise linear fitting, the main controller collects the current I in the optical amplifier area SOA At the same time, the phase zone current I is adaptively adjusted according to the fitted linear relationship phase Make compensation and realize wavelength calibration.

[0094] Specifically, the fuzzy PID control algorithm is used to adaptively compensate the output power. By dynamically adjusting the PID parameters, it can adapt to power fluctuations under different working conditions and improve the robustness of the system. Taking into account the characteristic that the power drift of the DBR laser increases over time, the long-term stability is significantly improved. The wavelength calibration algorithm realizes accurate compensation of the wavelength by constructing the corresponding relationship between the current in the optical amplification area and the current in the phase area, cleverly solving the problem of cross-influence of wavelength and power caused by the thermal effect of SOA and improving the wavelength stability.

[0095] The present embodiment also provides a wavelength and power adaptive compensation system for a DBR tunable laser, comprising: a data acquisition module, which is used to control the laser to generate laser light using a constant current source, and to send the laser light to a wavelength monitor and a power monitor simultaneously using a beam splitter, to detect the wavelength and output power of the laser, and to obtain two output signals related to the wavelength drift and output power fluctuation of the laser; a data processing module, which is used to limit the amplitude, reduce noise and stabilize the amplitude of the wavelength and output power, set requirements for the wavelength accuracy of the laser tuning, and set the power reference point of the full wavelength range; an adaptive compensation module, which is used to adaptively compensate the output power of the laser based on a fuzzy PID control algorithm, and to adaptively compensate the wavelength of the laser based on a wavelength calibration algorithm, so as to achieve synchronous stabilization of the laser wavelength and output power.

[0096] This embodiment also provides a computer device, which is applicable to a wavelength and power adaptive compensation method for a DBR tunable laser, and includes: a memory and a processor; the memory is used to store computer executable instructions, and the processor is used to execute the computer executable instructions to implement a wavelength and power adaptive compensation method for a DBR tunable laser as proposed in the above embodiment.

[0097] The computer device may be a terminal, and the computer device includes a processor, a memory, a communication interface, a display screen and an input device connected via a system bus. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be achieved through WIFI, an operator network, NFC (near field communication) or other technologies. The display screen of the computer device may be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device may be a touch layer covering the display screen, or a key, trackball or touchpad provided on the housing of the computer device, or an external keyboard, touchpad or mouse, etc.

[0098] This embodiment also provides a storage medium on which a computer program is stored. When the program is executed by a processor, a wavelength and power adaptive compensation method for a DBR tunable laser is implemented as proposed in the above embodiment; the storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (Static Random Access Memory, referred to as SRAM), electrically erasable programmable read-only memory (Electrically Erasable Programmable Read-Only Memory, referred to as EEPROM), erasable programmable read-only memory (Erasable Programmable Read Only Memory, referred to as EPROM), programmable read-only memory (Programmable Red-Only Memory, referred to as PROM), read-only memory (Read-Only Memory, referred to as ROM), magnetic storage, flash memory, magnetic disk or optical disk.

[0099] In summary, the present invention proposes a wavelength and power adaptive compensation method for a DBR tunable laser, which can solve the problem of wavelength and power cross-influence caused by inner loop feedback and ensure the simultaneous stability of wavelength and power; the adaptive compensation system has a simple structure and can simultaneously limit the amplitude, stabilize the amplitude and perform noise reduction filtering processing on the output signals of two monitoring units, and is easy to implement; the adaptive compensation system overcomes the defect of low control accuracy of laser wavelength stability in the prior art, and uses a fuzzy PID control algorithm based on a power monitoring loop to monitor and stabilize the power, and designs a wavelength calibration algorithm based on a wavelength monitoring loop to monitor and stabilize the wavelength, thereby achieving high-precision synchronous stability of laser wavelength and power.

[0100] Example 2

[0101] Reference Figure 7 to Figure 13 , which is the second embodiment of the present invention. This embodiment is different from the first embodiment in that, in order to verify its beneficial effects, operating data and related instructions of the present invention in an actual environment are provided.

[0102] This example uses the fuzzy PID control algorithm to compensate the output power of the laser, including fuzzification, establishing a fuzzy rule table and clarifying the process. After the input is fuzzified, the proportional coefficient K is constructed using the empirical method and trial and error method. P , integral coefficient K I and the differential coefficient K D The fuzzy rule table is as follows: Figure 7 to Figure 9 As shown, the fuzzy coefficient ΔK is calculated by three fuzzy rule tables. P , fuzzy coefficient ΔK I and the fuzziness coefficient ΔK D After the clarification process is performed, the proportional coefficient K P , integral coefficient K I and the differential coefficient K D The membership degree of the fuzzy subset is used to calculate the determined value of the output quantity, thereby realizing adaptive compensation of the laser output power.

[0103] For adaptive compensation of laser wavelength, due to the thermal effect of SOA, the wavelength will drift while compensating the power, which will cause the cross-influence of wavelength and power. Therefore, the core of wavelength calibration lies in adaptively adjusting the phase zone current I phase ; By setting the phase zone current I phase The scanning range is 0~7.5mA, the scanning step is 0.01mA, and the phase zone current I phase The tuning characteristics of Fig.10 As shown in the figure, it can be seen that there are multiple linear tuning regions with different slopes. phase As the wavelength increases, it will continue to blueshift until a jump occurs. When the current values ​​of the left reflector and the right reflector are different, the phase zone current I phase The tuning characteristics are also different, but overall they all show a periodic linear change trend. For example, in the scanning range of 0 to 7.5 mA, the data in the third linear tuning area is most suitable as compensation data. The wavelength coverage range of the third linear tuning area is large, the wavelength change is relatively gentle, the accuracy is higher, and the overall linearity is good, which is easy to fit and compensate. In the third linear tuning area, the phase zone current I phase For every 0.01mA increase, the wavelength blue shifts by approximately 1pm.

[0104] Based on the above phase zone current I phaseThe tuning characteristics of the laser wavelength are used to adaptively compensate for the laser wavelength. First, the standard output wavelength of the MG-Y laser is determined, and then a set of left reflector currents I left and the right reflector current I right , so that the side mode suppression ratio of the laser output corresponding to the wavelength is maximized, and the left reflector current I is fixed left , right reflector current I right and gain region current I gain , set the phase zone current I phase The scanning step is 0.01mA, the scanning range is 0~7.5mA, and after scanning, multiple phase zone currents I with different slopes can be obtained. phase The linear tuning area is selected, and the area with the highest wavelength accuracy and wavelength coverage greater than or equal to 0.2nm is selected, and the corresponding area is specified as the wavelength calibration data segment; then the optical amplifier current I SOA Scan in steps of 1 mA until the output power range of the MG-Y laser is covered, where the optical amplifier current I SOA The scanning starting point is 28mA; the scanning light amplification area current I SOA At the same time, the phase zone current I is adjusted according to the compensation data segment phase , get the calibrated wavelength, make the calibrated wavelength infinitely close to the standard output wavelength, and get the optical amplifier current I SOA -Phase zone current I phase Lookup table; the light amplification area current I in the lookup table SOA and phase zone current I phase After piecewise linear fitting, the main controller collects the current I in the optical amplifier area SOA At the same time, the phase zone current I is adaptively adjusted according to the fitted linear relationship phase Compensation is performed to achieve wavelength calibration.

[0105] After the above-mentioned adaptive compensation of laser output power, Fig.11 The figure shows the comparison of the adaptive compensation results of the laser output power. It can be seen from the figure that before calibration, the output power of the MG-Y laser shows obvious sawtooth fluctuations, while after calibration, the output power of the MG-Y laser tends to be stable.

[0106] like Fig.12 and Fig.13 The figure shows the adaptive compensation result of the laser wavelength before and after calibration. It can be seen from the figure that as the current I SOAAs the power increases, the output power of the laser gradually increases, but the wavelength of the laser is prone to jump. After calibration, the problem of easy wavelength jump can be solved. Therefore, it can be seen from the above data that the present invention can solve the problem of wavelength and power cross-influence caused by inner loop feedback, and realize high-precision synchronization and stability of laser wavelength and power.

[0107] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A wavelength and power adaptive compensation method for a DBR tunable laser, characterized in that: include: Use a constant current source to control the operation of the laser and collect the wavelength and output power of the laser; performing signal processing on the wavelength and the output power; Defining the wavelength accuracy and power reference point of the laser; The output power and wavelength of the laser are adaptively compensated based on the limiting process.

2. The wavelength and power adaptive compensation method of a DBR tunable laser according to claim 1, characterized in that: The operation of the laser controlled by the constant current source is to query the initial wavelength current lookup table by the main controller, send the address bit and the data bit to the constant current source chip, so that the multiple constant current sources output the specified current, thereby making the laser generate laser light; The wavelength and output power of the laser are collected by sending the laser to a wavelength monitor and a power monitor simultaneously through a beam splitter, detecting the wavelength and power of the laser to obtain two output signals related to the wavelength drift and output power fluctuation of the laser.

3. The wavelength and power adaptive compensation method of a DBR tunable laser according to claim 2, characterized in that: The signal processing includes: The current signal output by the photodetector is converted into a current-to-voltage using a transimpedance amplifier, and the converted voltage signal cannot exceed the supply voltage of the analog-to-digital converter; Filter and reduce noise on the output signal to stabilize the amplitude; The definition process includes setting the wavelength accuracy of laser tuning and setting the power reference point over the full wavelength range.

4. The wavelength and power adaptive compensation method of a DBR tunable laser as claimed in claim 3, characterized in that: The adaptive compensation includes adaptively compensating the output power of the laser based on a fuzzy PID control algorithm and adaptively compensating the wavelength of the laser based on a wavelength calibration algorithm; The adaptive compensation of the output power of the laser based on the fuzzy PID control algorithm comprises the following steps: The power inner loop feedback loop is used to achieve power stability of the laser. Considering that the signal processor processes data in discrete form, the fuzzy PID control algorithm is used to stabilize the power. The calculation formula of the PID adjustment method of the power control current is as follows: Where u(k) is the control signal sent by the signal processor; K P is the proportional coefficient, where the fuzzy PID coefficient includes the proportional coefficient K P , integral coefficient K I and the differential coefficient K D ; e(k) is the difference between the set standard power voltage threshold and the power feedback voltage collected for the kth time; K I is the integral coefficient; k is the number of feedback iterations; e(j) is the difference between the set standard power voltage threshold and the power feedback voltage collected for the jth time; K D is the differential coefficient.

5. The wavelength and power adaptive compensation method of a DBR tunable laser as claimed in claim 4, characterized in that: The calculation formula of the fuzzy PID coefficient is as follows: K P =K P0 +ΔK P K I =K I0 +ΔK I K D =K D0 +ΔK D Among them, K P is the proportionality coefficient; K P0 is the initial value of the proportionality coefficient; ΔK P is the fuzzy coefficient; K I is the integral coefficient; K I0 is the initial value of the integral coefficient; ΔK I is the fuzzy coefficient; K D is the differential coefficient; K D0 is the initial value of the differential coefficient; ΔK D is the fuzzy coefficient; The adaptive compensation of the wavelength of the laser based on the wavelength calibration algorithm comprises the following steps: Part of the laser light is input into the frequency discriminator and the photodetector to obtain a wavelength deviation signal; The fine tuning region of the laser is used for current compensation, where the current compensation factor increases as the current decreases.

6. The wavelength and power adaptive compensation method of a DBR tunable laser according to claim 5, characterized in that: The wavelength and power adaptive compensation system of the DBR tunable laser includes a laser chip, a collimating lens, an optical isolator, a beam splitter, a focusing lens, a wavelength monitor, a power monitor, a transimpedance low noise amplifier, an analog-to-digital converter, a signal processor and a constant current source module; The wavelength monitoring circuit includes a frequency discriminator, a photoelectric detector PD, an analog-to-digital converter, a signal processor and a constant current source; The power monitoring circuit includes a photodetector PD, an analog-to-digital converter, a signal processor, and a constant current source; The output end of the laser chip is connected to the input end of the wavelength monitor and the input end of the power monitor respectively through a beam splitter; The output end of the wavelength monitor and the output end of the power monitor are connected to the input end of the low-noise amplifier module to obtain wavelength and power feedback signals. The feedback signals are processed by a signal processor, and the compensation signals of wavelength and power are calculated through a fuzzy PID control algorithm and a wavelength calibration algorithm, thereby controlling the constant current source and adjusting the current.

7. The wavelength and power adaptive compensation method of a DBR tunable laser according to claim 6, characterized in that: The wavelength monitor, power monitor, laser chip, collimating lens, optical isolator, beam splitter and focusing lens are integrated in a butterfly package tube; The laser chip is a DBR type semiconductor, including a grating region, a phase region, a gain region and an optical amplification region; The frequency discriminator is a FP etalon, a gas absorption cell or a grating; The butterfly-shaped packaging tube is provided with a TEC cooler for stabilizing the temperature of the laser chip and the optical device.

8. A wavelength and power adaptive compensation system for a DBR tunable laser, based on a wavelength and power adaptive compensation method for a DBR tunable laser according to any one of claims 1 to 7, characterized in that: include, A data acquisition module is used to control the laser to generate laser light using a constant current source, and to send the laser light to a wavelength monitor and a power monitor simultaneously using a beam splitter, to detect the wavelength and output power of the laser light, and to obtain two output signals related to the wavelength drift and output power fluctuation of the laser light; Data processing module, used to limit, reduce noise and stabilize the wavelength and output power, set requirements for wavelength accuracy of laser tuning, and set power reference points across the entire wavelength range; The adaptive compensation module is used to adaptively compensate the output power of the laser based on the fuzzy PID control algorithm, and adaptively compensate the wavelength of the laser based on the wavelength calibration algorithm, so as to achieve synchronous stabilization of the laser wavelength and output power.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the wavelength and power adaptive compensation method of a DBR tunable laser according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the wavelength and power adaptive compensation method of a DBR tunable laser according to any one of claims 1 to 7 are implemented.

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