Self-adaptive circuit, method and optical module

Abstract

The invention discloses a self-adaptive circuit, a self-adaptive method and an optical module. The circuit comprises a control module and a laser driving module, the laser driving module comprises a variable gain amplifier VGA and a continuous time linear equalizer CTLE; the control module is used for comparing the first voltage signal with a preset threshold voltage signal to obtain a comparison result; based on the comparison result, a control signal is sent to the laser driving module; wherein the first voltage signal is obtained by performing statistical analysis on a stored digital signal by the control module; the control signal is used for controlling the laser driving module to adjust register settings of the VGA and the CTLE; the laser driving module is used for adjusting register settings of the VGA and the CTLE based on the control signal; wherein registers of the VGA and the CTLE are adjusted to different register values.

Description

Technical Field

[0001] The present application relates to the field of optical communications, and in particular to an adaptive circuit, method and optical module. Background Art

[0002] In the laser driver of linear-drive pluggable optical modules (LPO), with the introduction of high-order modulation formats, the complexity of the signal increases significantly, resulting in more stringent performance requirements for the transmission link. In addition, the LPO solution of the related technology is difficult to adapt to the changing external environment in long-distance transmission scenarios, which will cause the performance of the optical module to deteriorate to a certain extent, resulting in signal distortion or increased bit errors. Summary of the invention

[0003] In order to solve the above technical problems, the embodiments of the present application provide an adaptive circuit, method and optical module.

[0004] The adaptive circuit provided in the embodiment of the present application includes: a control module and a laser driving module; the laser driving module includes a variable gain amplifier VGA and a continuous time linear equalizer CTLE; wherein,

[0005] The control module is used to compare the first voltage signal with a preset threshold voltage signal to obtain a comparison result; based on the comparison result, send a control signal to the laser driving module; wherein the first voltage signal is obtained by the control module performing a statistical analysis on a stored digital signal; and the control signal is used to control the laser driving module to adjust the register settings of the VGA and the CTLE;

[0006] The laser driving module is used to adjust the register settings of the VGA and the CTLE based on the control signal; wherein the registers of the VGA and the CTLE are adjusted to different register values.

[0007] The adaptive method provided in the embodiment of the present application is applied to any one of the above adaptive circuits, including:

[0008] Comparing the first voltage signal with a preset threshold voltage signal to obtain a comparison result; wherein the first voltage signal is obtained by the control module performing statistical analysis on the stored digital signal;

[0009] Based on the comparison result, the register settings of the VGA and the CTLE in the laser driving module are adjusted; wherein the registers of the VGA and the CTLE are adjusted to different register values.

[0010] The optical module provided in the embodiment of the present application includes any one of the above-mentioned adaptive circuits.

[0011] In the technical solution of the embodiment of the present application, the adaptive circuit includes a control module and a laser driving module, and the laser driving module includes a variable gain amplifier (Variable Gain Amplifier, VGA) and a continuous time linear equalizer (Continuous Time Linear Equalization, CTLE); wherein the control module is used to compare the first voltage signal with a preset threshold voltage signal to obtain a comparison result, and based on the comparison result, send a control signal to the laser driving module; the laser driving module is used to adjust the register settings of the VGA and the CTLE based on the control signal; wherein the first voltage signal is obtained by the control module performing statistical analysis on the stored digital signal; the control signal is used to control the laser driving module to adjust the register settings of the VGA and the CTLE, and the registers of the VGA and the CTLE are adjusted to different register values. In this way, when the external environment (such as temperature, input signal strength, transmission distance, etc.) changes, the threshold of the laser driver module can be adjusted by adjusting the register settings of VGA and CTLE, which can ensure the stability of the optical communication signal. By real-time monitoring of the optical eye diagram, the working parameters of the laser driver can be optimized, and signal attenuation and distortion can be effectively compensated. This can reduce signal distortion and bit errors in the optical communication process, thereby significantly improving the anti-interference ability and signal integrity of optical communication. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 The structure of the adaptive circuit provided in the embodiment of the present application is shown in FIG. Figure 1 ;

[0013] Figure 2 It is a schematic diagram of an optical eye diagram of an NRZ signal and a PAM4 signal provided in an embodiment of the present application;

[0014] Figure 3 The structure of the adaptive circuit provided in the embodiment of the present application is shown in FIG. Figure 2 ;

[0015] Figure 4 is a schematic diagram of the structure of a laser driving module provided in an embodiment of the present application;

[0016] Figure 5 is a schematic diagram of the histogram statistics of the NRZ signal provided in the embodiment of the present application;

[0017] Figure 6 is a schematic diagram of the histogram statistics of the PAM4 signal provided in an embodiment of the present application;

[0018] Figure 7 is a schematic diagram of the principle of a test module in a beam splitting module provided in an embodiment of the present application;

[0019] Figure 8It is a flowchart of the adaptive method provided in the embodiment of the present application;

[0020] Fig. 9 It is a structural schematic diagram of an optical eye diagram threshold adaptive circuit applied to an MZM Driver provided in an embodiment of the present application;

[0021] Fig.10 It is a flowchart of an adaptive method for an optical eye diagram threshold adaptive circuit applied to an MZM Driver provided in an embodiment of the present application;

[0022] Fig.11 It is a structural schematic diagram of an optical eye diagram threshold adaptive circuit applied to a DML Driver provided in an embodiment of the present application;

[0023] Fig.12 It is a flowchart of an adaptive method for an optical eye diagram threshold adaptive circuit applied to a DML Driver provided in an embodiment of the present application;

[0024] Fig.13 It is a structural schematic diagram of an optical eye diagram threshold adaptive circuit applied to an EML Driver provided in an embodiment of the present application;

[0025] Fig.14 It is a flowchart of an adaptive method for an optical eye diagram threshold adaptive circuit applied to an EML Driver provided in an embodiment of the present application. DETAILED DESCRIPTION

[0026] The following will describe the technical solutions in the embodiments of the present application in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0027] To facilitate understanding of the technical solutions of the embodiments of the present application, the relevant technologies of the embodiments of the present application are described below. The following related technologies can be arbitrarily combined with the technical solutions of the embodiments of the present application as optional solutions, and they all belong to the protection scope of the embodiments of the present application.

[0028] In recent years, the rapid development of optical communication technology has promoted the widespread application of laser drivers in the field of high-speed data transmission. With the continuous expansion of data centers, 5G networks and VLSI, laser drivers are facing the demand for higher bandwidth, lower latency and more stable signal quality. In order to meet these needs, laser drivers are gradually adopting advanced technologies, such as high-order modulation formats - 4-Level Pulse Amplitude Modulation (PAM4) and Quadrature Amplitude Modulation (QAM), silicon photonic integration, and new laser and modulator designs. The integration of these technologies not only improves the transmission rate and spectral efficiency of laser drivers, but also enables them to achieve lower power consumption and higher signal integrity in a variety of application scenarios.

[0029] In traditional optical modules, the Digital Signal Processor (DSP) and Clock Data Recovery (CDR) modules are responsible for complex signal processing and noise reduction operations in the transmission and reception paths, which improves the signal quality but also increases the power consumption and cost of the module. The main difference between the LPO solution and the traditional optical module solution is that it uses linear direct drive technology and removes the DSP and CDR modules. This design idea entrusts the signal nonlinearity repair function to the switch system side. The optical transmitter module itself only retains the continuous time linear equalizer, and the optical receiver module itself only retains the equalization circuit for nonlinear repair, which simplifies the design and reduces the cost. In other words, the main advantage of the LPO solution is that it has higher operating energy efficiency when large-scale deployment is required. However, due to the removal of the traditional DSP and CDR modules, the optical module is insufficient in its ability to process complex signals, which sacrifices the system bit error rate and transmission distance. Therefore, the LPO solution is only suitable for short-distance transmission scenarios. In response to long-distance transmission requirements, as working conditions (such as temperature, input signal strength, transmission distance, etc.) change, fixed thresholds are difficult to adapt to the changing external environment, resulting in reduced performance of the optical module, and even signal distortion or increased bit errors. Therefore, based on the above problems, it is necessary to design a circuit that can adaptively adjust the optical eye diagram threshold to compensate for these missing functions to ensure the stability and accuracy of the signal during transmission.

[0030] Here, the signal definition in the related art is first explained.

[0031] (1) Non-Return-to-Zero (NRZ) signal. NRZ signal is a commonly used encoding method in digital communication. In NRZ encoding, each binary bit is converted into a signal level, a high level indicates that the binary bit is "1", and a low level indicates that the binary bit is "0". During transmission, the NRZ signal remains at the corresponding level until the next binary bit needs to be encoded. NRZ signals have been widely used in some communication systems with relatively less stringent synchronization requirements, such as early Ethernet and some low-speed transmission scenarios in optical fiber communications.

[0032] (2) PAM4 signal. The PAM4 signal divides the amplitude of the signal into four different levels, each of which can carry two bits of binary information, such as Gray-coded "00", "01", "11", and "10". In this way, each symbol period can represent two bits of logical information, and can transmit double the data rate under the same bandwidth. It has been widely used in data centers, high-speed Ethernet, optical communications and other fields. For example, in 400G optical modules, PAM4 modulation technology is used to achieve higher data transmission rates. Among them, the PAM4 signal has the following characteristics:

[0033] 1) High bandwidth utilization. Compared with traditional NRZ signals, PAM4 signals can transmit more data in the same bandwidth, effectively improving bandwidth utilization, which is of great significance for high-speed data transmission.

[0034] 2) Reduce the baud rate. At the same data transmission rate, the baud rate of the PAM4 signal is only half of that of the NRZ signal, which means that the PAM4 signal has relatively low channel bandwidth requirements during signal transmission, and the signal loss caused by the channel is also greatly reduced.

[0035] 3) Sensitive to noise. The eye height of the PAM4 signal is one-third of that of the NRZ signal, which leads to a higher signal-to-noise ratio requirement and makes the signal more susceptible to noise interference, resulting in a higher bit error rate.

[0036] 4) Complex design and testing. Since PAM4 signals have four levels, two bits of binary information per level, and small eye heights per level, nonlinear eye diagrams are more likely to occur, and the challenges faced during design and testing are more severe.

[0037] To ensure the stability of the signal during transmission, the optical eye diagram threshold adaptive solutions provided in the relevant technology specifically include the following:

[0038] (1) A power supply noise stabilization circuit is introduced to deal with the power supply ripple noise caused by the heavy load brought by the high-speed switching of the multiplexer (MUX) and the pre-driver stage, and a distortion current optimization circuit is introduced to respectively adjust the bias current of the top data / center data / bottom data to realize the opening and closing of each eye in the PAM4 signal.

[0039] (2) A "coarse adjustment + fine adjustment" threshold voltage tracking loop is designed based on the statistical characteristics of the effective bits after the Gray code decoder decodes the NRZ / PAM4 / PAM8 signal to achieve extremely strong compatibility of circuit code elements.

[0040] (3) The erroneous code is determined by the error-corrected code to accurately adjust the PAM4 signal threshold.

[0041] (4) A parallel adaptive state-reducing sequence detector for PAM4 transceiver is proposed, and the adaptive parameter adjustment of the detector is achieved through a zero-forcing algorithm based on inter-symbol interference (ISI).

[0042] (5) Closed-loop control is achieved by detecting the photocurrent (average value) generated by the backlight diode. Automatic Power Control (APC) adjusts the bias current to keep the average optical power output by the optical module stable, thereby maintaining the opening height and amplitude of the eye diagram.

[0043] However, the above solution still has the following problems:

[0044] (1) The application field of the first solution mentioned above is the transmitter circuit at the front end of the laser driver. Although its distortion current optimization circuit can adjust the opening and closing of the output optical eye diagram and avoid the distortion problem to a certain extent, this solution is not an adaptive control method. The tail current of the three data channels is controlled by registers.

[0045] (2) The second and third solutions mentioned above are both threshold detection / adaptive circuits / systems / methods acting on the receiver. Their focus is not on the laser driver and they cannot guarantee the threshold stability of the laser output optical eye diagram.

[0046] (3) The fourth solution mentioned above is essentially an extension of the traditional transceiver architecture and is not suitable for the LPO solution.

[0047] (4) The fifth solution mentioned above focuses on the average value of the current and adjusts the opening height and amplitude of the optical eye diagram, which is not suitable for the optical eye diagram quality control of the PAM4 signal.

[0048] Based on this, in order to solve the above-mentioned technical problems, the present application proposes an optical eye diagram threshold adaptive circuit for a laser driver in a linear-driven pluggable optical module. When the external environment (such as temperature, input signal strength, transmission distance, etc.) changes, the threshold of the laser driver is dynamically adjusted in real time, and the optical eye diagram is monitored in real time to optimize the working parameters of the laser driver. This can ensure the stability of the optical communication signal, effectively compensate for signal attenuation and distortion, and reduce signal distortion and bit errors during optical communication, thereby significantly improving the anti-interference capability and signal integrity of optical communication.

[0049] To facilitate understanding of the technical solutions of the embodiments of the present application, the technical solutions of the present application are described in detail below through specific embodiments. The above related technologies can be combined arbitrarily with the technical solutions of the embodiments of the present application as optional solutions, and they all belong to the protection scope of the embodiments of the present application. The embodiments of the present application include at least part of the following contents.

[0050] The embodiment of the present application provides an adaptive circuit. Specifically, the adaptive circuit is an optical eye diagram threshold adaptive circuit. Figure 1 The structure of the adaptive circuit provided in the embodiment of the present application is shown in FIG. Figure 1 ,like Figure 1 As shown, the adaptive circuit includes: a control module 100 and a laser driving module 200; the laser driving module 200 includes a VGA and a CTLE; wherein,

[0051] The control module 100 is used to compare the first voltage signal with a preset threshold voltage signal to obtain a comparison result; based on the comparison result, a control signal is sent to the laser driving module; wherein the first voltage signal is obtained by the control module performing statistical analysis on the stored digital signal; the control signal is used to control the laser driving module to adjust the register settings of VGA and CTLE;

[0052] The laser driving module 200 is used to adjust the register settings of the VGA and the CTLE based on the control signal; wherein the registers of the VGA and the CTLE are adjusted to different register values.

[0053] In an embodiment of the present application, the control module 100 compares the first voltage signal with a preset threshold voltage signal, generates a control signal according to the comparison result, and sends the control signal to the laser driving module 200 to control the laser driving module 200 to adjust the register settings of VGA and CTLE based on the control signal.

[0054] Here, after the laser driving module 200 adjusts the register settings of the VGA and CTLE based on the control signal, due to the different functions of the VGA and CTLE (the VGA is responsible for adjusting the gain and amplifying the input signal to the appropriate amplitude, and the CTLE is used for nonlinear repair and is responsible for compensating for high-frequency components to compensate for channel losses), the registers of the VGA and CTLE will be adjusted to different register values.

[0055] There are no limitations on the operations for adjusting the register settings of the VGA and CTLE. For example, the VGA gain can be selected through the Quartus Assignment Editor, the Quartus Setting File (QSF), or the Avalon-MM registers; or the CTLE settings can be changed by reading and modifying specific register values; or the VGA and CTLE can be adjusted by writing a register configuration script, which usually involves the address, value, and write mask of the register.

[0056] It should be noted that after adjusting the register settings of VGA and CTLE, it is necessary to verify whether the quality of the optical signal has been improved through optical eye diagram analysis, so that the laser driving module 200 can output a stable optical eye diagram threshold through continuous feedback adjustment to ensure the stability of the optical communication signal. The optical eye diagram threshold refers to the minimum intensity threshold of the optical eye diagram signal.

[0057] like Figure 2 The figure shows the optical eye diagram of NRZ signal and PAM4 signal. The optical eye diagram signal refers to a series of optical signal waveforms overlapped and displayed through the persistence mode of the oscilloscope to form an eye-like figure (eye diagram), which is used to observe the overall characteristics and quality of the signal and help analyze inter-symbol interference and noise. When evaluating the optical eye diagram signal, the commonly used measurement standards include eye height, eye width, jitter and extinction ratio. For example, in the optical eye diagram of NRZ signal, the eye height and eye width represent the amplitude and stability of the NRZ signal respectively, and the jitter reflects the fluctuation of the NRZ signal. The extinction ratio is the ratio of the "1" level to the "0" level in the eye diagram. The higher the extinction ratio, the better the quality of the NRZ signal.

[0058] In the technical solution of the embodiment of the present application, the adaptive circuit includes a control module and a laser driving module, and the laser driving module includes a VGA and a CTLE; wherein the control module is used to compare the first voltage signal with the preset threshold voltage signal to obtain a comparison result, and based on the comparison result, send a control signal to the laser driving module; the laser driving module is used to adjust the register settings of the VGA and the CTLE based on the control signal; wherein the first voltage signal is obtained by the control module performing statistical analysis on the stored digital signal; the control signal is used to control the laser driving module to adjust the register settings of the VGA and the CTLE, and the registers of the VGA and the CTLE are adjusted to different register values. In this way, when the external environment (such as temperature, input signal strength, transmission distance, etc.) changes, the threshold of the laser driving module is adjusted by adjusting the register settings of the VGA and the CTLE, which can ensure the stability of the optical communication signal, and optimize the working parameters of the laser driving module by real-time monitoring of the optical eye diagram, effectively compensate for signal attenuation and distortion, and reduce the signal distortion and bit error in the optical communication process, thereby significantly improving the anti-interference ability and signal integrity of the optical communication.

[0059] The embodiment of the present application further proposes an adaptive circuit. Specifically, the adaptive circuit is an optical eye diagram threshold adaptive circuit. Figure 3 The structure of the adaptive circuit provided in the embodiment of the present application is shown in FIG. Figure 2 ,like Figure 3 As shown, the adaptive circuit includes: a control module 100, a laser driving module 200, a light source and modulation module 300, a beam splitting module 400, a photoelectric conversion module 500 and an analog-to-digital conversion module 600; the laser driving module 200 includes a VGA and a CTLE; wherein,

[0060] The light source and modulation module 300 is used to send a modulated light signal to the beam splitting module 400, where the modulated light signal is obtained by performing phase and / or amplitude modulation on the initial light signal by the light source and modulation module 300;

[0061] The beam splitting module 400 is used to send a first optical signal to the photoelectric conversion module 500; and send a second optical signal to the output path, wherein the first optical signal and the second optical signal are obtained by the beam splitting module 400 performing a beam splitting process of a preset ratio on the modulated optical signal; wherein the intensity of the first optical signal is less than the intensity of the second optical signal;

[0062] The photoelectric conversion module 500 is used to send a second voltage signal to the analog-to-digital conversion module 600, where the second voltage signal is obtained by converting the first optical signal by the photoelectric conversion module 500;

[0063] The analog-to-digital conversion module 600 is used to send a digital signal to the control module 100, where the digital signal is obtained by converting the second voltage signal by the analog-to-digital conversion module 600;

[0064] The control module 100 is used to compare the first voltage signal with a preset threshold voltage signal to obtain a comparison result; based on the comparison result, a control signal is sent to the laser driving module; wherein the first voltage signal is obtained by the control module performing statistical analysis on the stored digital signal; the control signal is used to control the laser driving module to adjust the register settings of VGA and CTLE;

[0065] The laser driving module 200 is used to adjust the register settings of the VGA and the CTLE based on the control signal; wherein the registers of the VGA and the CTLE are adjusted to different register values.

[0066] In the embodiment of the present application, the laser driving module 200 provides an injection current or voltage for the light source and the modulation module 300, and the light source and the modulation module 300 output a modulated light signal, and send the modulated light signal to the beam splitting module 400; after receiving the modulated light signal, the light beam module 400 performs a beam splitting process on the modulated light signal in a preset ratio to obtain a first light signal and a second light signal, and sends most of the second light signal to the output path, and sends a small part of the first light signal to the photoelectric conversion module 500; after receiving the first light signal, the photoelectric conversion module 500 converts the first light signal into a second voltage signal, and sends the second voltage signal to the analog-to-digital conversion module 600; after receiving the second voltage signal, the analog-to-digital conversion module 600 converts the first light signal into a second voltage signal, and sends the second voltage signal to the analog-to-digital conversion module 600; After receiving the digital signal, the control module 100 converts the digital signal into a first voltage signal, compares the first voltage signal with a preset threshold voltage signal, generates a control signal according to the comparison result, and sends the control signal to the laser driving module 200; after receiving the control signal, the laser driving module 200 adjusts the register settings of VGA and CTLE based on the control signal to change the threshold of the laser driving module 200, so that when the laser driving module 200 provides the injection current or voltage to the light source and the modulation module 300, the intensity of the optical signal output by the light source and the modulation module 300 can be changed. In this way, the stability of the optical communication signal can be ensured by continuously performing feedback adjustment on the output optical signal.

[0067] In some embodiments, the light source and modulation module 300 includes a laser 301 and / or a modulator 302; wherein,

[0068] The laser 301 is used to output an initial optical signal; or, to send a modulated optical signal to the beam splitting module 400; wherein, when the laser 301 sends a modulated optical signal to the beam splitting module 400, the modulated optical signal is generated by the laser 301 when the laser driving module 200 provides a modulated current or voltage to the laser 301;

[0069] The modulator 302 is used to send a modulated optical signal to the beam splitting module 400. The modulated optical signal is obtained by performing phase and / or amplitude modulation on the initial optical signal by the modulator 302. In some embodiments, the photoelectric conversion module 500 includes a photodetector 501 and a transimpedance amplifier 502;

[0070] The photodetector 501 is used to send a current signal to the transimpedance amplifier 502, where the current signal is obtained by converting the first light signal by the photodetector 501;

[0071] The transimpedance amplifier 502 is used to send a second voltage signal to the analog-to-digital conversion module 600 . The second voltage signal is obtained by converting the current signal by the transimpedance amplifier 502 .

[0072] In some embodiments, a first end of the laser driving module 200 is connected to a first end of the analog-to-digital conversion module 600 , and a second end of the laser driving module 200 is connected to a first end of the light source and modulation module 300 .

[0073] In some embodiments, the first end of the beam splitting module 400 is connected to the second end of the light source and modulation module 300, the second end of the beam splitting module 400 is connected to the first end of the photoelectric conversion module 500, and the second end of the analog-to-digital conversion module 600 is connected to the second end of the photoelectric conversion module 500.

[0074] The photoelectric conversion module 500 includes a photodetector 501 and a transimpedance amplifier 502. Specifically, the second end of the beam splitting module 400 is connected to the first end of the photodetector 501, the first end of the transimpedance amplifier 502 is connected to the second end of the photodetector 501, and the second end of the transimpedance amplifier 502 is connected to the second end of the analog-to-digital conversion module 600.

[0075] It should be noted that the control module 100 may also be a controller 100 , the laser driving module 200 may also be a laser driver 200 , the beam splitting module 400 may also be a beam splitter 400 , and the analog-to-digital conversion module 600 may also be an analog-to-digital converter 600 .

[0076] Here, the control module 100 can obtain a corresponding voltage signal by analyzing the stored digital signal, compare the analyzed voltage signal with reference data (preset threshold voltage signal), and send a control signal to the laser driving module 200 according to the comparison result. The laser driving module 200 can adjust the register settings of the VGA and CTLE in the laser driving module 200 based on the control signal to change the gain and bandwidth.

[0077] Here, the laser driving module 200 is at the end of the optical transmitter, and is used to amplify the output signal of the previous circuit, and input the modulated electrical signal in the form of current or voltage to the light source and modulation module 300 to realize the conversion of electrical signal to optical signal. The laser driving module mainly includes VGA, CTLE and main driving stage circuit, such as Figure 4 The figure shows the structure diagram of the laser driving module. The VGA is responsible for adjusting the gain and amplifying the input signal to a suitable amplitude. The CTLE is used for nonlinear repair and is responsible for compensating the high-frequency component to compensate for the channel loss. The main driving stage circuit provides the light source and the modulation module 300 with a modulated electrical signal in the form of current or voltage to realize the modulated output of the optical signal.

[0078] It should be noted that the control module 100 can support the user to set the optical eye diagram threshold. Since the initial optical eye diagram threshold setting value is the optical power, the user needs to first calibrate the optical eye diagram threshold adaptive circuit through the initial calibration mode, and then complete the setting of the optical eye diagram threshold. The purpose of the initial calibration is to clarify the overall conversion gain including the splitting ratio of the beam splitting module 400 and the conversion gain of the photoelectric conversion module 500, so as to track the threshold. The specific implementation process is as follows:

[0079] In the initial calibration mode, first ensure that the system is connected correctly, and prepare a standard light source with known and stable optical power. The laser driving module 200 stops inputting modulation signals to the light source and modulation module 300, and turns off the optical switch between the light source and modulation module 300 and the beam splitting module 400. At this time, the laser has no optical signal output to the beam splitting module 400; connect the standard light source to the input end of the beam splitting module 400; start the system, let the optical signal of the standard light source pass through the beam splitting module 400, and feed back to the photoelectric conversion module 500 to output the corresponding analog voltage signal, and further convert the analog voltage signal into a digital signal through the analog-to-digital conversion module 600; calculate and store the overall conversion gain based on the measured analog voltage signal and the input standard optical power.

[0080] Exemplarily, in the application scenario of NRZ signal, the user first enters the initial calibration mode and performs the calibration operation, and the overall conversion gain is calculated and stored according to the above calibration process; after completing the calibration operation, the user sets the optical eye diagram threshold, specifically, sets two optical eye diagram thresholds, and multiplies the two optical eye diagram thresholds with the calculated overall conversion gain to obtain reference data and store it; the control module 100 performs histogram statistical analysis on the stored digital signal to obtain V + and V -After the two voltage signals are analyzed, the two voltage signals are compared with the reference data, and the register settings of VGA and CTLE in the laser driving module 200 are changed according to the comparison results to change the gain and bandwidth; through continuous feedback regulation, the laser driving module 200 finally outputs a stable optical eye diagram threshold to ensure the stability of the optical communication signal. Figure 5 Shown is a histogram statistical diagram of the NRZ signal.

[0081] Exemplarily, in the application scenario of PAM4 signal, the user first enters the initial calibration mode and performs the calibration operation, calculates and stores the overall conversion gain; after completing the calibration operation, the user sets the optical eye diagram threshold, specifically, sets four optical eye diagram thresholds, and multiplies the four optical eye diagram thresholds by the calculated overall conversion gain to obtain reference data and store it; after the controller module 100 performs histogram statistical analysis on the stored digital signal to obtain four voltage signals V0, V1, V2, and V3, the four analyzed voltage signals are compared with the reference data, and the register settings of VGA and CTLE in the laser driver module 200 are changed according to the comparison results to change the gain and bandwidth; through continuous feedback regulation, the output optical eye diagram threshold is finally stabilized. Among them, Figure 6 The figure shows a histogram statistical diagram of a PAM4 signal.

[0082] Here, the light source and modulation module 300 includes one of the following: a Mach-Zehnder Modulator (MZM); a directly modulated laser (DML); or an electro-absorption modulated laser (EML).

[0083] According to different modulation modes, the light source and the modulation module 300 can be divided into the following categories:

[0084] (1) In the MZM application scenario, a laser diode (LD) under a fixed current bias generates a constant-power optical signal, which further enters the MZM through an optical fiber or an optical waveguide. The MZM consists of an input / output waveguide, a Y-shaped branch including a beam splitter, two modulation arms, and a Y-shaped branch including a beam combiner. Specifically, the input optical signal is divided into two optical signals of equal power at the Y-shaped branch including the beam splitter, and enters the upper and lower modulation arms for transmission respectively. The two modulation arms are made of electro-optical materials, and their refractive index changes with the size of the externally applied electrical signal. By applying different voltages to the upper and lower optical waveguides, the refractive index of the electro-optical crystal can be changed, thereby changing the amplitude and phase of the optical signal. Finally, the two optical signals are combined into one optical signal at the Y-shaped branch including the beam combiner and output. That is to say, when the light source and modulation module 300 is an MZM, the light source and modulation module 300 includes a laser 301 and a modulator 302, the laser driving module 200 generates a fixed current, and the laser 301 under the fixed current bias generates an initial optical signal with a constant power, which further enters the modulator 302 through an optical fiber or an optical waveguide, and the modulator 302 performs phase and / or amplitude modulation on the initial optical signal and outputs a modulated optical signal.

[0085] (2) The core structure of DML includes active area, waveguide and electrode. In the application scenario of DML, the light source used is usually LD under modulated current bias, and LD can be vertical cavity surface emitting laser (VCSEL), distributed feedback laser (DFL), Fabry-Perot laser (FPL), etc. The output optical power of DML is directly modulated by changing the injection current of LD, where the injection current of LD is provided by the front-stage laser driver; when the injection current changes, the carrier concentration in the active area changes, which causes the output intensity of light to change, so DML usually does not require an additional independent modulator. DML has the advantages of simple structure, low cost, and easy integration, so it is widely used in short-distance communication. That is to say, when the light source and modulation module 300 is DML, the light source and modulation module 300 only includes laser 301, but not modulator 302. At this time, the initial optical signal output by laser 301 is the modulated optical signal.

[0086] (3) In EML application scenarios, an external modulator is usually integrated into the LD, and the external modulator is called an electro-absorption modulator (EAM). The difference between EML and DML is that the bias current of the LD is a constant current, and the signal modulation of the EML is not on the LD side but on the EAM side, which means that the EML obtains optical signals of different intensities by changing the proportion of light passing through. That is, when the light source and modulation module 300 is an EML, the light source and modulation module 300 includes a laser 301 and a modulator 302, and the modulator 302 is integrated in the laser 301. The laser driving module 200 generates a fixed current, and the laser 301 under the fixed current bias generates an initial optical signal of constant power, and the initial optical signal is further phase- and / or amplitude-modulated by the modulator 302 in the laser 301 and the modulated optical signal is output.

[0087] Here, the beam splitting module 400 is an optical device based on interference and diffusion of light, and its main function is to split the input optical signal into several optical signals with the characteristics of the original light beam according to a certain ratio, and then transmit them to different device units respectively. The diameter and phase of these light beams remain unchanged, but the power and propagation direction change. The beam splitting ratio of the beam splitting module 400 can be set according to actual needs to meet different application scenarios, and no limitation is made here. For example, in the optical eye diagram threshold adaptive circuit, a small part of the optical signal can be split out for monitoring and feedback control, and most of the optical signal continues to be transmitted.

[0088] It should be noted that a test module needs to be reserved at the input end of the beam splitter module 400 to meet the user's need for initial calibration of the optical eye diagram threshold adaptive circuit. The specific process is as follows: in the initial calibration mode, the control module 100 selects the optical signal from the standard light source to enter the beam splitter module 400, and at the same time closes the optical signal input switch of the light source and the modulation module 300 to perform the subsequent initial calibration operation of the optical eye diagram threshold adaptive circuit. Figure 7 Shown is a schematic diagram of the principle of the test module in the beam splitting module.

[0089] Here, the photoelectric conversion module 500 is responsible for converting the optical signal into an electrical signal for subsequent electrical signal processing. The photoelectric conversion module 500 mainly includes a photodetector - an avalanche photodiode (APD) and a transimpedance amplifier (TIA). APD is a photodiode with internal gain, which is responsible for converting the optical signal into a current signal. Its structure includes a PN junction, a multiplication region, and an electrode. When the optical signal is irradiated onto the APD, the photons are absorbed to generate electron-hole pairs. Under high reverse bias, the electron-hole pairs are accelerated in the multiplication region, thereby generating an avalanche multiplication effect, so that the output current is amplified. APD has the advantages of high sensitivity and low noise. It can detect weak optical signals and is suitable for long-distance optical communications and low optical power application scenarios. TIA is an amplifier used to convert current signals into voltage signals. Its structure usually includes input stage, feedback resistor and output stage. The input stage converts the current signal into a voltage signal, and the feedback resistor determines the gain of the amplifier. The output stage outputs the amplified voltage signal to the subsequent circuit. TIA has the advantages of high gain, low noise, and wide bandwidth. It can amplify the weak current signal output by the APD to a processable voltage level for subsequent signal processing and analysis.

[0090] Here, the analog-to-digital conversion module 600 load converts the analog voltage signal output by the photoelectric conversion module 500 into a digital signal for processing and analysis by the control module 100. The analog-to-digital conversion module 600 is usually composed of a sampling and holding circuit, a quantizer, and an encoder; the sampling and holding circuit samples and holds the input analog voltage signal, the quantizer converts the sampled analog voltage signal into a digital signal, and the encoder encodes and outputs the quantized digital signal. The analog-to-digital conversion module 600 has the advantages of high-speed conversion, high precision, and low noise. It can accurately digitize the analog voltage signal that changes rapidly in a short time, meeting the requirements of the optical communication system for high-speed data processing.

[0091] In the technical solution of the embodiment of the present application, the adaptive circuit includes a control module and a laser driving module, and the laser driving module includes a VGA and a CTLE; wherein the control module is used to compare the first voltage signal with the preset threshold voltage signal to obtain a comparison result, and based on the comparison result, send a control signal to the laser driving module; the laser driving module is used to adjust the register settings of the VGA and the CTLE based on the control signal; wherein the first voltage signal is obtained by the control module performing statistical analysis on the stored digital signal; the control signal is used to control the laser driving module to adjust the register settings of the VGA and the CTLE, and the registers of the VGA and the CTLE are adjusted to different register values. In this way, when the external environment (such as temperature, input signal strength, transmission distance, etc.) changes, the threshold of the laser driving module is adjusted by adjusting the register settings of the VGA and the CTLE, which can ensure the stability of the optical communication signal, and by real-time monitoring of the optical eye diagram, the working parameters of the laser driver are optimized, and the signal attenuation and distortion are effectively compensated, which can reduce the signal distortion and bit error in the optical communication process, thereby significantly improving the anti-interference ability and signal integrity of the optical communication.

[0092] The present application also provides an adaptive method, which is applied to any adaptive circuit provided in the above embodiments. Figure 8 is a flow chart of the adaptive method provided in the embodiment of the present application, such as Figure 8 As shown, the method comprises the following steps:

[0093] Step 801: Compare a first voltage signal with a preset threshold voltage signal to obtain a comparison result. The first voltage signal is obtained by the control module 100 performing statistical analysis on a stored digital signal.

[0094] In the embodiment of the present application, the adaptive circuit includes a control module 100 and a laser driving module 200. The control module 100 is used to perform statistical analysis on the stored digital signal to obtain a first voltage signal, and compare the first voltage signal with a preset threshold voltage signal to obtain a comparison result, which represents the comparison between the corresponding value of the first voltage signal and the corresponding value of the preset threshold voltage signal. Among them, the preset threshold voltage signal is a reference data set by the user according to actual needs (different application scenarios).

[0095] Step 802: Based on the comparison result, adjust the register settings of VGA and CTLE in the laser driving module 200. The registers of VGA and CTLE are adjusted to different register values.

[0096] In the embodiment of the present application, after obtaining the comparison result between the first voltage signal and the preset threshold voltage signal, the control module 100 generates a control signal based on the comparison result, and sends the control signal to the laser driving module 200 to control the change of the register settings of VGA and CTLE in the laser driving module 200. After receiving the control signal, the laser driving module 200 adjusts the register settings of VGA and CTLE based on the control signal.

[0097] Here, there is no limitation on the operations for adjusting the register settings of VGA and CTLE. For example, the VGA gain can be selected through the Quartus Assignment Editor, QSF, or Avalon-MM registers; or the CTLE settings can be changed by reading and modifying specific register values; or the VGA and CTLE can be adjusted by writing register configuration scripts, which usually involve the register address, value, and write mask.

[0098] It should be noted that after adjusting the register settings of VGA and CTLE, it is necessary to verify whether the quality of the optical signal has improved through optical eye diagram analysis, so that through continuous feedback adjustment, the laser driving module 200 can output a stable optical eye diagram threshold to ensure the stability of the optical communication signal.

[0099] In some embodiments, after adjusting the register settings of VGA and CTLE in the laser driving module 200, the gain and bandwidth of the signal will change, thereby being able to adjust the intensity and frequency of the output optical signal, wherein the output optical signal is a modulated optical signal output by the light source and modulation module 300.

[0100] In some embodiments, the above method further comprises:

[0101] Performing phase and / or amplitude modulation on the initial optical signal to obtain a modulated optical signal;

[0102] Performing a beam splitting process of a preset ratio on the modulated optical signal to obtain a first optical signal and a second optical signal; wherein the intensity of the first optical signal is less than the intensity of the second optical signal, and the second optical signal flows to the output path;

[0103] The first optical signal is converted into a current signal, the current signal is converted into a second voltage signal, and the second voltage signal is converted into a digital signal.

[0104] Specifically, the adaptive circuit further includes a light source and modulation module 300 , a beam splitting module 400 , a photoelectric conversion module 500 and an analog-to-digital conversion module 600 . The laser driving module 200 provides an injection current or voltage for the light source and modulation module 300, and the light source and modulation module 300 outputs a modulated optical signal and sends the modulated optical signal to the beam splitting module 400, wherein the light source and modulation module 300 includes a laser 301 and / or a modulator 302. When the light source and modulation module 300 only includes the laser 301, the modulated optical signal is generated by the laser 301 when the laser driving module 200 provides a modulation current or voltage for the laser 301. When the light source and modulation module 300 includes the laser 301 and the modulator 302, the modulated optical signal is obtained by performing phase and / or amplitude modulation on the initial optical signal generated by the laser 301 by the modulator 302; the beam splitting module 400 is used to perform a preset ratio of beam splitting processing on the modulated optical signal to obtain a first optical signal and a second optical signal, and send the first optical signal to the photoelectric conversion module 500, wherein the first optical signal is a small part of the optical signal, and its intensity is less than the intensity of the second optical signal, and the second optical signal flows to the output path; the photoelectric conversion module 500 is used to convert the first optical signal into an electrical signal. Specifically, the photoelectric conversion module includes a photodetector 501 and a transimpedance amplifier 502. The photodetector 501 is used to convert the first optical signal into a current signal, and the transimpedance amplifier 502 is used to convert the current signal into a second voltage signal. The analog-to-digital conversion module 600 is used to convert the second voltage signal into a digital signal, and store the digital signal in the control module 100 for subsequent signal processing and analysis. The control module 100 is used to convert the digital signal into a first voltage signal, and compare the first voltage signal with a preset threshold voltage signal, generate a control signal according to the comparison result, and send the control signal to the laser driving module 200. The laser driving module 200 is used to adjust the register settings of the VGA and CTLE based on the control signal to change the threshold of the laser driving module 200, so that when the laser driving module 200 provides the injection current or voltage to the light source and the modulation module 300, the light signal intensity output by the light source and the modulation module 300 can be changed. In this way, by continuously feedback-adjusting the output optical signal, the stability of the optical communication signal can be ensured.

[0105] Here, since the light source and modulation module 300 includes any one of MZM, DML, and EML, different modulation modes correspond to different application embodiments, so a specific application scenario description is given below.

[0106] Application Example 1

[0107] like Fig. 9 The figure shows the structure diagram of the optical eye diagram threshold adaptive circuit applied to the MZM Driver. Fig.10The figure shows a flow chart of an adaptive method for an optical eye diagram threshold adaptive circuit applied to an MZM Driver. In the MZM Driver application scenario, the method corresponding to the scenario includes the following steps:

[0108] Step 1001: the user first enters the initial calibration mode to perform a calibration operation. After completing the calibration operation, the user sets the optical eye diagram threshold and further obtains reference data. The optical eye diagram threshold adaptive circuit starts to work formally.

[0109] Step 1002: The LD under fixed current bias generates a constant power optical signal, and the constant power optical signal further enters the MZM through an optical fiber or an optical waveguide. When the constant power optical signal passes through the MZM modulator, the optical signal is divided into two optical signals of equal power at the Y-shaped branch including the beam splitter, and enters the upper and lower two modulation arms modulated by the RF signal output by the laser driver for phase or amplitude modulation respectively; finally, the two optical signals are combined into one optical signal at the Y-shaped branch including the beam combiner, and the modulated optical signal is output through the optical fiber.

[0110] Step 1003: The modulated optical signal output by the MZM enters the beam splitter, which splits the modulated optical signal into two optical signals with the characteristics of the original optical beam according to a certain ratio (for example, 1:99), and irradiates a small part of the optical signal to the APD for monitoring and feedback control, while most of the optical signal continues to be transmitted and flows to the output path.

[0111] Step 1004: The APD converts the optical signal into a current signal, and amplifies the current signal output by the APD to a processable voltage level via a high-speed TIA, which serves as the input of the high-speed analog-to-digital converter and is stored in the controller for subsequent signal processing and analysis.

[0112] Step 1005: The controller can obtain a corresponding number of voltage signals (two voltage signals for NRZ signal and four voltage signals for PAM4 signal) by performing histogram statistical analysis on the stored digital signal, compare the analyzed voltage signals with the reference data, and change the register settings of VGA and CTLE in the laser driver according to the comparison results to change the gain and bandwidth. Through continuous feedback control, the output optical eye diagram threshold is finally stabilized.

[0113] Application Example 2

[0114] like Fig.11 The figure shows the structure diagram of the optical eye diagram threshold adaptive circuit applied to the DML Driver. Fig.12The figure shows a flow chart of an adaptive method for an optical eye diagram threshold adaptive circuit applied to a DML Driver. In the DML Driver application scenario, the method corresponding to the scenario includes the following steps:

[0115] Step 1201: the user first enters the initial calibration mode to perform a calibration operation. After completing the calibration operation, the user sets the optical eye diagram threshold and further obtains reference data. The optical eye diagram threshold adaptive circuit starts to work formally.

[0116] Step 1202: The injection current of the LD is provided by the laser driver. The injection current specifically includes: a bias (Ibias) current for providing a DC bias for the LD and a modulation (Imod) current for modulating the output optical power of the LD. When the injection current of the LD changes, the carrier concentration in the active region changes, thereby causing the light intensity output by the LD to change, thereby completing the modulation encoding of the optical signal.

[0117] Step 1203: The modulated optical signal output by the LD enters the beam splitter, which splits the modulated optical signal into two optical signals with the characteristics of the original optical beam in a certain ratio (for example, 1:99). A small part of the optical signal is irradiated to the APD for monitoring and feedback control, while most of the optical signal continues to be transmitted and flows to the output path.

[0118] Step 1204: The APD converts the optical signal into a current signal, and amplifies the current signal output by the APD to a processable voltage level via a high-speed TIA, which serves as the input of the high-speed analog-to-digital converter and is stored in the controller for subsequent signal processing and analysis.

[0119] Step 1205: The controller can obtain a corresponding number of voltage signals (two voltage signals for NRZ signal and four voltage signals for PAM4 signal) by performing histogram statistical analysis on the stored digital signal, compare the analyzed voltage signals with the reference data, and change the register settings of VGA and CTLE in the laser driver according to the comparison results to change the gain and bandwidth. Through continuous feedback control, the output optical eye diagram threshold is finally stabilized.

[0120] Application Example 3

[0121] like Fig.13 The figure shows the structure diagram of the optical eye diagram threshold adaptive circuit applied to the EML Driver. Fig.14 The figure shows a flow chart of an adaptive method for an optical eye diagram threshold adaptive circuit applied to an EML Driver. In the EML Driver application scenario, the method corresponding to the scenario includes the following steps:

[0122] Step 1401: the user first enters the initial calibration mode to perform a calibration operation. After completing the calibration operation, the user sets the optical eye diagram threshold and further obtains reference data. The optical eye diagram threshold adaptive circuit starts to work formally.

[0123] Step 1402: The bias current of the LD is a constant current, and the modulation voltage signal of the laser driver controls the EAM, and optical signals of different intensities are obtained by changing the proportion of light.

[0124] Step 1403: The modulated optical signal output by the EAM enters the beam splitter and is split into two optical signals with the characteristics of the original optical beam in a certain ratio (e.g., 1:99). A small portion of the optical signal is irradiated to the APD for monitoring and feedback control, while most of the optical signal continues to be transmitted and flows to the output path.

[0125] Step 1404: The APD converts the optical signal into a current signal, and amplifies the current signal output by the APD to a processable voltage level via a high-speed TIA, which serves as the input of the high-speed analog-to-digital converter and is stored in the controller for subsequent signal processing and analysis.

[0126] Step 1405: The controller can obtain a corresponding number of voltage signals (two voltage signals for NRZ signal and four voltage signals for PAM4 signal) by performing histogram statistical analysis on the stored digital signal, compare the analyzed voltage signals with the reference data, and change the register settings of VGA and CTLE in the laser driver according to the comparison results to change the gain and bandwidth. Through continuous feedback control, the output optical eye diagram threshold is finally stabilized.

[0127] In the technical solution of the embodiment of the present application, the comparison result is obtained by comparing the first voltage signal with the preset threshold voltage signal, and based on the comparison result, the register settings of VGA and CTLE in the laser driving module are adjusted; wherein, the first voltage signal is obtained by the control module performing statistical analysis on the stored digital signal, and the registers of VGA and CTLE are adjusted to different register values. In this way, when the external environment (such as temperature, input signal strength, transmission distance, etc.) changes, the threshold of the laser driving module is adjusted by adjusting the register settings of VGA and CTLE, which can ensure the stability of the optical communication signal, and optimize the working parameters of the laser driver by real-time monitoring of the optical eye diagram, effectively compensate for signal attenuation and distortion, and reduce the signal distortion and bit error in the optical communication process, thereby significantly improving the anti-interference ability and signal integrity of the optical communication.

[0128] An embodiment of the present application further provides an optical module, which includes any one of the adaptive circuits provided in the above embodiments. Specifically, the adaptive circuit is an optical eye diagram threshold adaptive circuit.

[0129] Any adaptive circuit provided in the embodiments of the present application can be applied to various optical communication scenarios. Preferably, any adaptive circuit provided in the embodiments of the present application is suitable for high-speed optical communication systems with high signal quality requirements.

[0130] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0131] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0132] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0133] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0134] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0135] If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, server, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (Read-Only Memory,) ROM, random access memory (RandomAccess Memory, RAM), disk or optical disk and other media that can store program codes.

[0136] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. An adaptive circuit, characterized in that: The circuit includes: a control module and a laser driving module; the laser driving module includes a variable gain amplifier VGA and a continuous time linear equalizer CTLE; wherein, The control module is used to compare the first voltage signal with a preset threshold voltage signal to obtain a comparison result; based on the comparison result, send a control signal to the laser driving module; wherein the first voltage signal is obtained by the control module performing a statistical analysis on a stored digital signal; and the control signal is used to control the laser driving module to adjust the register settings of the VGA and the CTLE; The laser driving module is used to adjust the register settings of the VGA and the CTLE based on the control signal; wherein the registers of the VGA and the CTLE are adjusted to different register values.

2. The circuit according to claim 1, characterized in that The circuit also includes: a light source and modulation module, a beam splitting module, a photoelectric conversion module and an analog-to-digital conversion module; wherein, The light source and modulation module are used to send a modulated light signal to the beam splitting module, wherein the modulated light signal is obtained by performing phase and / or amplitude modulation on an initial light signal by the light source and modulation module; The beam splitting module is used to send a first optical signal to the photoelectric conversion module; and send a second optical signal to the output path, wherein the first optical signal and the second optical signal are obtained by the beam splitting module performing a preset ratio of beam splitting on the modulated optical signal; wherein the intensity of the first optical signal is less than the intensity of the second optical signal; The photoelectric conversion module is used to send a second voltage signal to the analog-to-digital conversion module, where the second voltage signal is obtained by converting the first optical signal by the photoelectric conversion module; The analog-to-digital conversion module is used to send a digital signal to the control module, and the digital signal is obtained by converting the second voltage signal by the analog-to-digital conversion module.

3. The circuit according to claim 2, characterized in that The light source and modulation module include a laser and / or a modulator; wherein, The laser is used to output the initial optical signal; or, to send the modulated optical signal to the beam splitting module; wherein, when the laser sends the modulated optical signal to the beam splitting module, the modulated optical signal is generated by the laser when the laser driving module provides a modulated current or voltage to the laser; The modulator is used to send the modulated optical signal to the beam splitting module, and the modulated optical signal is obtained by performing phase and / or amplitude modulation on the initial optical signal by the modulator.

4. The circuit according to claim 3, characterized in that The photoelectric conversion module includes a photodetector and a transimpedance amplifier; wherein, The photodetector is used to send a current signal to the transimpedance amplifier, wherein the current signal is obtained by converting the first light signal by the photodetector; The transimpedance amplifier is used to send the second voltage signal to the analog-to-digital conversion module, where the second voltage signal is obtained by converting the current signal by the transimpedance amplifier.

5. The circuit according to claim 4, characterized in that The first end of the laser driving module is connected to the first end of the analog-to-digital conversion module, and the second end of the laser driving module is connected to the first end of the light source and modulation module.

6. The circuit according to claim 5, characterized in that The first end of the beam splitter module is connected to the second end of the light source and modulation module, the second end of the beam splitter module is connected to the first end of the photoelectric conversion module, and the second end of the analog-to-digital conversion module is connected to the second end of the photoelectric conversion module.

7. The circuit according to claim 6, characterized in that The second end of the beam splitting module is connected to the first end of the photodetector, the first end of the transimpedance amplifier is connected to the second end of the photodetector, and the second end of the transimpedance amplifier is connected to the second end of the analog-to-digital conversion module.

8. An adaptive method, characterized in that Applied to the adaptive circuit according to any one of claims 1 to 7, the method comprising: Comparing the first voltage signal with a preset threshold voltage signal to obtain a comparison result; wherein the first voltage signal is obtained by the control module performing statistical analysis on the stored digital signal; Based on the comparison result, the register settings of the VGA and the CTLE in the laser driving module are adjusted; wherein the registers of the VGA and the CTLE are adjusted to different register values.

9. The method according to claim 8, characterized in that The method further comprises: Performing phase and / or amplitude modulation on the initial optical signal to obtain a modulated optical signal; Performing a beam splitting process of a preset ratio on the modulated optical signal to obtain a first optical signal and a second optical signal; wherein the intensity of the first optical signal is less than the intensity of the second optical signal, and the second optical signal flows to an output path; The first optical signal is converted into a current signal, the current signal is converted into a second voltage signal, and the second voltage signal is converted into a digital signal.

10. An optical module, characterized in that: The optical module comprises the adaptive circuit according to any one of claims 1 to 7.

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