Optical module link defect monitoring method and system

Abstract

The invention discloses an optical module link defect monitoring method and system. A reflected light signal in an optical module link is obtained in a polarization conversion or polarization separation mode, and a multi-stage and multi-section reflected light monitoring technology concept is provided; the scheme mainly aims at a two-stage two-section reflected light monitoring technology, a two-stage two-section circuit is composed of a first circuit and a second circuit, the dynamic range of light current to be monitored is divided into two sections through the first circuit and the second circuit, the first section is directly collected after being subjected to first-stage amplification processing by the first circuit, and the second section is directly collected after being subjected to second-stage amplification processing by the second circuit. The second section is subjected to first-stage amplification processing through the first circuit, then is subjected to second-stage amplification processing through the second circuit and is collected; therefore, the acquisition range of the light current signal can be ensured, and the acquisition precision when the light current signal is small can be ensured.

Description

Technical Field

[0001] The present invention relates to the field of optical communication technology, and in particular to a method and system for monitoring optical module link defects. Background Art

[0002] As a key component in fiber-optic broadband services, the performance of optical modules is directly related to the efficiency and reliability of data transmission. Among the many technical specifications of optical modules, the reflected light intensity of the reflective link is gaining increasing attention. Reflected light intensity refers to the intensity of the optical signal emitted by the optical module and reflected back from the optical fiber or other medium. This parameter is crucial for ensuring correct data transmission and system stability.

[0003] When the reflected light intensity is too high, it interferes with the optical module's laser transmitter, causing signal distortion and increased bit error rates. This increased bit error rate not only reduces data transmission efficiency but can also cause communication interruptions, severely impacting the performance of optical communication systems. Therefore, real-time monitoring and early warning of reflected light intensity in reflective links have become a key technology for improving the reliability of optical communication systems.

[0004] Existing technologies for detecting and collecting photocurrent signals mostly use a photodetector connected to a resistor and then directly collect the data through an analog-to-digital converter. However, when detecting and collecting light signals reflected from optical modules, such as in applications where each channel of a silicon photonics module operates at 100Gbps or 200Gbps, the optical transmission environment is complex and changeable. Large reflections on the optical path will seriously affect the system's transmission performance, while smaller reflections can also cause adverse effects such as flicker and MPI. Therefore, it is necessary to monitor signals with a wider dynamic range, and it is necessary to monitor photocurrents in the range of 50nA to 50uA or wider. The accuracy and monitoring dynamic range of traditional methods are far from sufficient. The effective number of bits of a typical analog-to-digital converter is 10 bits. Combined with the influence of power supply noise and amplifier noise in the circuit, even if the effective number of bits of the analog-to-digital converter is increased, it is difficult to monitor photocurrents in the range of 50nA to 50uA. At the same time, existing technologies have obvious limitations in solving the problem of monitoring the intensity of reflected light in reflective links. Therefore, it is urgent to develop a new and effective reflected light intensity monitoring and early warning method to overcome the shortcomings of existing technologies and meet the growing performance requirements of optical communication systems. Summary of the Invention

[0005] The technical problem to be solved by the present invention is that the existing methods for detecting and collecting photocurrent signals are far from sufficient in terms of accuracy and monitoring dynamic range when detecting and collecting signals such as reflected light signals from silicon photonic modules that require monitoring of a wide dynamic range; even if the effective number of bits of the analog-to-digital converter is increased, it is difficult to monitor photocurrents with a large monitoring dynamic range (50nA~50uA); the purpose of the present invention is to provide a method and system for monitoring defects in an optical module link, which obtains reflected light signals in an optical module link by polarization conversion or polarization separation, and proposes a multi-level and multi-segment monitoring method. Technology, this solution is mainly aimed at the two-stage two-segment reflected light monitoring technology. The two-stage two-segment circuit is composed of a first circuit and a second circuit. The dynamic range of the photocurrent to be monitored is divided into two segments by the first circuit and the second circuit. The first segment is directly collected by the first circuit after the first stage amplification processing, and the second segment is collected after the first stage amplification processing by the first circuit and then the second stage amplification processing by the second circuit. In this way, it can ensure the collection range of the electrical signal (photocurrent signal) of the reflected light of the silicon photonic module, and can also ensure the collection accuracy when the electrical signal (photocurrent signal) of the reflected light of the silicon photonic module is relatively small.

[0006] The present invention is achieved through the following technical solutions: This solution provides a method for monitoring optical module link defects, including: Obtain the reflected light signal in the optical module link and convert it into an electrical signal; The method for obtaining the reflected light signal comprises: a transmitting end of the optical module sends a main optical signal to the optical module link; obtaining a return optical signal returned from the optical module link, and separating the reflected light signal from the return optical signal based on a polarization control beam splitter or a polarization beam splitter; Performing a first-stage amplification process on the electrical signal to obtain a first electrical signal, performing a second-stage amplification process on the first electrical signal to obtain a second electrical signal, ..., performing an n+1-th-stage amplification process on the n-th electrical signal to obtain an n+1-th electrical signal; n≥1; Based on the amplification process of each level, a limit parameter is determined, and the i-th electrical signal is determined as the target electrical signal according to the limit parameter; i=1, 2, ..., n+1; The target electrical signal is monitored, and an alarm is issued when the target electrical signal exceeds an alarm threshold.

[0007] A further optimized solution is that when the reflected light signal is separated from the return light signal based on the polarization control beam splitter, the method of obtaining the reflected light signal in the optical module link further includes: The transmitting end of the optical module sends a first optical signal, and the polarization control beam splitter performs a first polarization conversion on the first optical signal to obtain a second optical signal that is sent to the optical module link; The polarization control beam splitter performs a second polarization conversion on the third optical signal returned in the optical module link to obtain a fourth optical signal and a fifth optical signal; the fourth optical signal is returned to the transmitting end of the optical module; the third optical signal is in a random polarization state; the random polarization state means that the optical signal is fixed in one or more polarization states at a certain moment; The fifth optical signal is used as the reflected optical signal.

[0008] When the reflected light signal is separated from the returned light signal based on the polarization beam splitter, the method of obtaining the reflected light signal in the optical module link includes: The transmitting end of the optical module sends a sixth optical signal to the optical module link, wherein the sixth optical signal is in the first polarization mode; obtains a seventh optical signal returned from the optical module link, performs polarization separation on the seventh optical signal to obtain an eighth optical signal and a ninth optical signal; the eighth optical signal is in the first polarization mode; and uses the ninth optical signal as the reflected optical signal.

[0009] A further optimization scheme is that, when n=1, the first stage amplification process is implemented based on the first circuit, and the second stage amplification process is implemented based on the second circuit; The first circuit includes: a first amplifier, a resistor R and a first analog-to-digital converter; one end of the resistor R is connected to the negative input terminal of the first amplifier, and the other end is connected to the output terminal of the first amplifier; the positive input terminal of the first amplifier is grounded; and the output terminal of the first amplifier is connected to the first analog-to-digital converter; The second circuit includes: a second amplifier, a resistor R3, a resistor R4, and a second analog-to-digital converter; one end of the resistor R3 is grounded, and the other end is connected to the negative input terminal of the second amplifier; one end of the resistor R4 is connected to the output terminal of the second amplifier, and the other end is connected to the negative input terminal of the second amplifier; the output terminal of the second amplifier is connected to the second analog-to-digital converter; The output terminal of the first amplifier is connected to the positive input terminal of the second amplifier.

[0010] A further optimized solution is to further include: a current mirror circuit, a transresistance amplifier circuit or a differential amplifier circuit; the current mirror circuit, the transresistance amplifier circuit or the differential amplifier circuit are all connected to the input end of the first circuit.

[0011] A further optimization solution is that both the first circuit and the second circuit include a filter circuit, the filter circuit is arranged between the first amplifier and the first analog-to-digital converter, and the filter circuit is arranged between the second amplifier and the second analog-to-digital converter.

[0012] A further optimization scheme is that when n=1, the method for determining the limit parameters includes: Determining a first circuit parameter and a first circuit gain parameter based on the maximum reflected light power and the photoelectric conversion efficiency of the reflected light signal; the first circuit gain parameter is a circuit gain parameter between the node where the electrical signal is emitted and the first node; the first node is the output end of the first amplifier; Determining a maximum saturated reflected light intensity of the second circuit based on the output accuracy of the first circuit; presetting a minimum voltage threshold and a minimum resolution threshold, wherein the maximum saturated reflected light intensity satisfies that the output voltage of the first circuit is greater than or equal to the minimum voltage threshold, and the output voltage resolution of the second circuit is greater than or equal to the minimum resolution threshold; Under the maximum saturated reflected light intensity of the second circuit, a second circuit gain parameter is determined; the second circuit gain parameter is the circuit gain from the first node to the second node; the second node is the output end of the second amplifier; obtaining an output voltage value of the first circuit when the second circuit has maximum saturated reflected light; The limit parameter is obtained by subtracting the reserved redundant voltage from the output voltage value of the first circuit.

[0013] A further optimized solution is that the method for determining the target electrical signal includes: When the first electrical signal is greater than or equal to the limit parameter, the first electrical signal is used as the target electrical signal; Otherwise, the second electrical signal is used as the target electrical signal.

[0014] A further optimized solution is to monitor the target electrical signal and issue an alarm when the target electrical signal exceeds an alarm threshold; including the following method: Preset alarm threshold A and alarm threshold B, where A>B; When Qi>A, a serious alarm signal is issued; When A>Qi>B, a general alarm signal is issued; When B>Qi, no alarm signal is generated; Among them, Qi is the target electrical signal.

[0015] A further optimization solution is that the optical module supports the common management interface specification CMIS, and monitors the reflected optical signal through the observable variable VDM in the specification.

[0016] This solution also provides an optical module link defect monitoring system, which is characterized in that it is used to implement the above-mentioned optical module link monitoring method, and the system includes: The detection module is used to obtain the reflected light signal in the optical module link and convert the reflected light signal into an electrical signal; a first amplifying module, configured to perform a first-stage amplification process on the electrical signal to obtain a first electrical signal; a second amplification module, configured to perform a second-stage amplification process on the first electrical signal to obtain a second electrical signal; …; The nth amplifying module performs the n+1th stage amplification processing on the nth electrical signal to obtain the n+1th electrical signal; n≥1; A parameter determination module is used to determine the limit parameters based on the amplification processing of each level, and to determine the i-th electrical signal as the target electrical signal according to the limit parameters; i=1, 2, ..., n+1; The alarm module is used to monitor the target electrical signal and issue an alarm when the target electrical signal exceeds an alarm threshold.

[0017] Compared with the prior art, the present invention has the following advantages and beneficial effects: 1. The present invention provides a method and system for monitoring defects in an optical module link. The method obtains reflected light signals in an optical module link through polarization conversion or polarization separation, and proposes a multi-stage, multi-segment reflected light monitoring technology. This solution is mainly directed to a two-stage, two-segment reflected light monitoring technology. The two-stage, two-segment circuit consists of a first circuit and a second circuit. The dynamic range of the photocurrent to be monitored is divided into two segments by the first circuit and the second circuit. The first segment is directly collected by the first circuit after first-stage amplification processing. The second segment is collected after first-stage amplification processing by the first circuit and then second-stage amplification processing by the second circuit. This ensures both the collection range of the electrical signal (photocurrent signal) and the collection accuracy when the electrical signal (photocurrent signal) is relatively small.

[0018] 2. The present invention provides a method and system for monitoring defects in an optical module link. The reflected light signal is converted and collected by a polarization-controlled beam splitter, or the reflected light signal is separated and collected by a polarization beam splitter, so that the reflected light signal is acquired without losing the transmitted light. At the same time, the reflected light signal will not lose intensity due to pure power separation, which is beneficial to the detection of the reflective link. At the same time, in order to facilitate the integration of the link monitoring structure with the optical module, this solution proposes a specific polarization-controlled beam splitter architecture that can be integrated with the optical module to realize the monitoring of the reflected light signal intensity, thereby avoiding the loss of the main optical path and the received reflected light in the link. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the following briefly introduces the drawings required for use in the examples. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be considered as limiting the scope. A person of ordinary skill in the art can also derive other relevant drawings based on these drawings without inventive effort. In the drawings: Figure 1 This is a flowchart of the optical module link monitoring method; Figure 2 Schematic diagram of the principle of implementation scheme A for obtaining reflected light signals; Figure 3 Schematic diagram of the principle of implementation scheme B for obtaining reflected light signals; Figure 4 Schematic diagram of the principle of implementation B1 of the implementation scheme of the reflected light signal B; Figure 5 Schematic diagram of the principle of implementation method B2 of the implementation scheme of the reflected light signal B; Figure 6 is a schematic diagram of a circuit for collecting the first electrical signal and the second electrical signal; Figure 7 Schematic diagram of the acquisition circuit connected to the current mirror circuit; Figure 8 Schematic diagram of the acquisition circuit connected to the transimpedance amplifier circuit; Figure 9 Schematic diagram of the acquisition circuit connected to the differential amplifier circuit; Figure 10 This is a schematic diagram of the voltage output results of the two-stage amplifier circuit for acquisition circuit simulation; Figure 11 This is a schematic diagram of the voltage difference result of the two-stage amplifier circuit in the acquisition circuit simulation; Figure 12 The structure of the scanning module is a schematic diagram; Figure 13 This is a schematic diagram of a practical application of Example 3; Figure 14 This is a schematic diagram of the second practical application of Example 3. DETAILED DESCRIPTION

[0020] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with examples and drawings. The exemplary embodiments of the present invention and their descriptions are only used to explain the present invention and are not intended to limit the present invention.

[0021] The existing methods for detecting and collecting photocurrent signals are far from accurate and have insufficient dynamic range when detecting and collecting signals such as reflected light signals from silicon photonic modules that require monitoring over a wide dynamic range. Even increasing the effective number of bits of the analog-to-digital converter (ADC) still makes it difficult to monitor photocurrents with a large dynamic range (50nA to 50uA). In view of this, the present invention provides the following embodiments to address the above-mentioned technical problems.

[0022] Example 1: This example provides a method for monitoring optical module link defects. Figure 1 As shown, including: Step 1: Obtain the reflected light signal in the optical module link and convert the reflected light signal into an electrical signal; The specific method for obtaining the reflected light signal includes: the transmitting end of the optical module sends a main optical signal to the optical module link; obtaining a return optical signal returned from the optical module link, and separating the reflected light signal from the return optical signal based on a polarization control beam splitter or a polarization beam splitter; As implementation scheme A of step 1, when the reflected light signal is separated from the returned light signal based on the polarization beam splitter, the method for acquiring the reflected light signal includes: The transmitting end of the optical module sends a sixth optical signal (6) to the optical module link, and the sixth optical signal (6) is in the first polarization mode; obtains the seventh optical signal (7) returned from the optical module link, and performs polarization separation on the seventh optical signal to obtain an eighth optical signal (8) and a ninth optical signal (9); the eighth optical signal (8) is in the first polarization mode; and the ninth optical signal (9) is used as the reflected optical signal. The ninth optical signal (9) is in any polarization mode other than the first polarization mode; The polarization beam splitter in implementation scheme A can separate the two polarization states; the transmitting end of the optical module sends out the sixth optical signal (6) of the TE transverse electric mode into the optical module link. As the optical module link is adjusted and the environment changes, the optical signal is no longer a pure TE transverse electric mode. If the polarization is orthogonally decomposed, a part of the TM transverse magnetic mode will generally remain. Therefore, this solution is designed based on the polarization characteristic difference that the reflected optical signal (the seventh optical signal (7)) returned by the optical module link is not a pure TE transverse electric mode. Figure 2 The reflected light signal separation architecture is shown in the figure. The seventh light signal (7) returned in the optical module link is input into the polarization beam splitter when returning to the optical module from the optical module link. The polarization beam splitter separates the reflected light signal of the TM transverse magnetic mode part (the ninth light signal (9)) and the reflected light signal of the TE transverse electric mode part (the eighth light signal (8)). At this time, the reflected light signal of the TM transverse magnetic mode part (the ninth light signal (9)) can be collected. According to the parameters such as the optical module system structure and experience, the proportional relationship between the reflected light signal of the TE transverse magnetic mode part and the reflected light signal of the TM transverse magnetic mode part is determined. Then, the complete reflected light signal intensity is monitored based on the reflected light signal of the TM transverse magnetic mode part.

[0023] like Figure 3 As shown in FIG. 1 , as implementation B of step 1, when the reflected light signal is separated from the returned light signal based on the polarization control beam splitter, the method for obtaining the reflected light signal further includes: The transmitting end of the optical module sends out a first optical signal (1), and the polarization control beam splitter performs a first polarization conversion on the first optical signal (1) to obtain a second optical signal (2) which is sent to the optical module link; The polarization control beam splitter performs a second polarization conversion on the third optical signal (3) returned in the optical module link to obtain a fourth optical signal (4) and a fifth optical signal (5); the fourth optical signal (4) returns to the transmitting end of the optical module; the third optical signal (3) is in a random polarization state; the random polarization state means that the optical signal is fixed to one or more polarization states at a certain moment; The fifth optical signal (5) is used as the reflected optical signal.

[0024] In this solution, the first optical signal (1) can be subjected to a first polarization conversion by a polarization control beam splitter, so that a second optical signal (2) of a certain polarization state can be output. Similarly, in the reverse direction, the third optical signal (3) of a random polarization state reflected back to the optical module can also be converted into a TM transverse magnetic mode polarized light orthogonal to the TE transverse electric mode light through the polarization control beam splitter and output from the other port to obtain a fifth optical signal (5) (reflected optical signal). The fifth optical signal (5) enters the photodetector and is converted into an electrical signal. The specific implementation methods are as follows: The implementation method B1 of the B implementation scheme is: like Figure 4 As shown, in this embodiment, the polarization control beam splitter is provided with two phase shifter groups (a first phase shifter group and a second phase shifter group) and two beam splitters (a first beam splitter and a second beam splitter); each phase shifter group has two phase shifters, and the front end of each phase shifter group is connected to a beam splitter, and the last phase shifter group is connected to the first port and the second port of the polarization state separation and merger, and the first port and the second port of the polarization state separation and merger are respectively connected to a phase shifter in the phase shifter group; the first beam splitter at the head end is connected to the TX end and the PD end, the first optical signal (1) enters the first beam splitter from the TX end, the fifth optical signal (5) is output from the first beam splitter to the PD end, and the fourth optical signal (4) is output from the first beam splitter to the TX end. The beam splitting ratio of the first beam splitter and the second beam splitter is 50:50; the polarization state separation and merger selects the polarization separation rotator; When the first optical signal (1) of the TE transverse electric mode is input into the polarization control beam splitter from the transmitting end of the optical module, the first beam splitter splits the first optical signal (1) into an A1 optical signal and a B1 optical signal. The A1 optical signal and the B1 optical signal enter the first phase shifter group, and the first phase shifter group performs phase adjustment on the two optical signals. When the two optical signals are combined in the second beam splitter, any splitting ratio can be output. The optical signals with different splitting ratios can then pass through the second phase shifter group to adjust the phase relationship between each other, so that the adjustment between linear polarization and circular polarization can be achieved in the subsequent polarization combining process of the polarization separation rotator.

[0025] When the third optical signal (3) returns to the optical module from the link, the third optical signal (3) of any polarization state will be decomposed into two orthogonal A polarization optical signals and B polarization optical signals through the polarization separation rotator, and the polarization state of the B polarization optical signal will be converted into the first mode, and the first mode is the polarization state of the A polarization optical signal; (in this embodiment, the TM transverse magnetic mode light is converted into the TE transverse electric mode light), that is, the polarization states of the A polarization optical signal and the B polarization optical signal entering the second phase shifter group are the same and have coherence characteristics. The phase relationship between the A polarization optical signal and the B polarization optical signal is adjusted by the second phase shifter group, so that the beam ratio can be adjusted to 50:50 when entering the second beam splitter, and the phase relationship of the two optical signals can be further adjusted when entering the first phase shifter group, so that the light is combined in the first beam splitter and output from the detection port. By adjusting the polarization control beam splitter, the intensity of the fourth optical signal (4) is 0, and the intensity of the fifth optical signal (5) is the maximum. The fifth optical signal (5) is converted into an electrical signal by the photoelectric detector.

[0026] As the implementation method B2 of embodiment B, Figure 5 As shown, in order to further optimize the structure of the polarization control beam splitter, the polarization control beam splitter has only one phase shifter group and one beam splitter. The phase shifter group includes two phase shifters, and the phase shifter group is arranged between the beam splitter and the polarization state separator / combiner. As a preferred embodiment, the beam splitter in this solution has a splitting ratio of 50:50. In this structure, one beam splitter and one phase shift arm group are reduced, which is conducive to increasing integration while reducing power consumption. When the first optical signal (1) of the TE transverse electric mode is input into the polarization control beam splitter through the TX end, the beam splitter splits the first optical signal into two beams, enters the phase shifter group for phase adjustment, and then is combined by the polarization separation rotator and realizes the adjustment between linear polarization and circular polarization to obtain a second optical signal (2) of a certain polarization state; conversely, when the third optical signal (3) returns to the optical module from the link, the third optical signal (3) of any polarization state will be decomposed into two orthogonal polarization state lights by the polarization separation rotator, and at the same time, the TM transverse magnetic mode light is converted into TE transverse electric mode light. The polarization state optical signal enters the phase shifter group to adjust the phase relationship between the two optical signals. Finally, the optical signal is intensity-divided by the beam splitter to obtain the fourth optical signal (4) and the fifth optical signal (5); at this time, the reflected optical signal of the fifth optical signal (5) is directly collected and enters the photodetector to be converted into an electrical signal.

[0027] Step 2: performing a first-stage amplification process on the electrical signal to obtain a first electrical signal, performing a second-stage amplification process on the first electrical signal to obtain a second electrical signal, ..., performing an n+1-th-stage amplification process on the n-th electrical signal to obtain an n+1-th electrical signal; n≥1; In the existing technology, when detecting and collecting photocurrent signals, most of them are directly collected by connecting a photodetector to a resistor and then directly collecting them through an analog-to-digital converter. However, when detecting and collecting reflected light signals from optical modules, such as in applications where each channel of a silicon photonic module is 100Gbps or 200Gbps, the optical transmission environment is changeable and complex. Large reflections on the optical path will seriously affect the transmission performance of the system, while smaller reflections will also cause adverse effects such as flicker and MPI on the system. Therefore, it is necessary to monitor signals with a wider dynamic range and monitor photocurrents in the range of 50nA to 50uA or wider. The accuracy and monitoring dynamic range of traditional methods are far from sufficient. The effective number of bits of a general analog-to-digital converter is 10 bits. Combined with the influence of power supply noise, amplifier noise, etc. in the circuit, even if the effective number of bits of the analog-to-digital converter is increased, it is difficult to monitor photocurrents in the range of 50nA to 50uA. In view of this, this embodiment specifically sets the following method for the application of silicon photonic modules to achieve detection and collection of reflected light signals; specifically: like Figure 6 As shown, this scheme mainly designs a two-stage amplification process, that is, n=1; The first stage amplification process is implemented based on the first circuit; the second stage amplification process is implemented based on the second circuit; The first circuit includes: a first amplifier, a resistor R and a first analog-to-digital converter; one end of the resistor R is connected to the negative input terminal of the first amplifier, and the other end is connected to the output terminal of the first amplifier; the positive input terminal of the first amplifier is grounded; and the output terminal of the first amplifier is connected to the first analog-to-digital converter ADC1; The second circuit includes: a second amplifier, a resistor R3, a resistor R4, and a second analog-to-digital converter; one end of the resistor R3 is grounded, and the other end is connected to the negative input terminal of the second amplifier; one end of the resistor R4 is connected to the output terminal of the second amplifier, and the other end is connected to the negative input terminal of the second amplifier; the output terminal of the second amplifier is connected to the second analog-to-digital converter ADC2; The output terminal of the first amplifier is connected to the positive input terminal of the second amplifier.

[0028] The first circuit and the second circuit both include a filter circuit, the filter circuit being disposed between the first amplifier and the first analog-to-digital converter, and the filter circuit being disposed between the second amplifier and the second analog-to-digital converter ADC2. The filter circuit disposed between the first amplifier and the first analog-to-digital converter ADC1 includes a resistor R2 and a capacitor C1, wherein the resistor R2 is connected between the first amplifier and the first analog-to-digital converter ADC1, and one end of the capacitor C1 is grounded and the other end is connected between the resistor R2 and the first analog-to-digital converter ADC1; the filter circuit disposed between the second amplifier and the second analog-to-digital converter ADC2 includes a resistor R5 and a capacitor C2, wherein the resistor R5 is connected between the second amplifier and the second analog-to-digital converter ADC2, and one end of the capacitor C2 is grounded and the other end is connected between the resistor R5 and the first analog-to-digital converter ADC2; This solution proposes a two-stage, two-segment reflected light monitoring technology. The two-stage, two-segment circuit consists of a first circuit and a second circuit. The dynamic range of the photocurrent to be monitored is divided into two segments by the first circuit and the second circuit. The first segment is subjected to I / V conversion, amplification and conditioning by the first amplifier by the first circuit, and is collected by the first analog-to-digital converter ADC1 after filtering. The second segment is subjected to I / V conversion and amplification conditioning by the first amplifier of the first circuit, and is then amplified, conditioned and filtered by the second circuit, and collected by the second analog-to-digital converter ADC2. This can ensure both the collection range of the electrical signal (photocurrent signal) and the collection accuracy when the electrical signal (photocurrent signal) is relatively small.

[0029] It also includes: a current mirror circuit, a transimpedance amplifier circuit or a differential amplifier circuit; the current mirror circuit, the transimpedance amplifier circuit or the differential amplifier circuit are all connected to the input end of the first circuit.

[0030] In high-speed silicon photonics technology, the cathode of the photodetector is generally grounded, and the anode outputs photocurrent. This solution provides an implementation method of adding a current mirror circuit to the first circuit. The two-stage two-segment circuit first adjusts the current direction through the current mirror circuit, then performs I / V conversion and amplification conditioning, and collects data in two stages and two segments. Figure 7 As shown, the current mirror circuit is composed of two transistors, one end of the current mirror circuit is connected to the photodetector, and the other end is connected to the negative input terminal of the first amplifier; This solution provides an implementation method of adding a transimpedance amplifier circuit to the first circuit, which converts the photocurrent into a voltage and then processes it through the first amplifier; Figure 8As shown, the transimpedance amplifier circuit includes a resistor R1, a resistor R6, a resistor R7, a resistor R8 and a third amplifier; one end of the resistor R1 is connected to the output end of the first amplifier, and the other end is connected to the negative input end of the first amplifier; one end of the resistor R7 is grounded, and the other end is connected to the positive input end of the first amplifier; one end of the resistor R6 is connected to the negative input end of the first amplifier, and the other end is connected to the output end of the third amplifier; one end of the resistor R8 is connected to the positive input end of the first amplifier, and the other end is grounded.

[0031] Considering that the current mirror is mainly composed of transistors and has limited precision, which is more prominent in the case of small current of the reflected signal in the silicon photonic module, and the use of high-precision current mirror is costly, this solution proposes a preferred solution for monitoring the photocurrent in the dynamic range of 50nA~50uA of the silicon photonic module: adding a differential amplifier circuit to the first circuit, such as Figure 9 As shown, the differential amplifier circuit includes a resistor R9, a resistor R10, a resistor R11, a resistor R12, a resistor R13, a resistor R14, a resistor R15, a resistor R16, a fourth amplifier and a fifth amplifier; One end of resistor R is connected to the photodetector, and the other end is connected to resistor R9; one end of resistor R10 is connected to the negative input of the fourth amplifier, and the other end is connected to the negative input of the fifth amplifier; the positive input of the fifth amplifier and the positive input of the fourth amplifier are respectively connected to the two sides of resistor R; one end of resistor R11 is connected to the negative input of the fourth amplifier, and the other end is connected in series with resistor R13 and then connected to the positive input of the first amplifier; one end of resistor R12 is connected to the negative input of the fifth amplifier, and the other end is connected in series with resistor R15 and then connected to the negative input of the first amplifier; one end of resistor R14 is connected to the positive input of the first amplifier, and the other end is grounded; the output of the fourth amplifier is connected between resistor R11 and resistor R13, the output of the fifth amplifier is connected between resistor R12 and resistor R15, and one end of resistor R16 is connected to the negative input of the first amplifier, and the other end is connected to the output of the first amplifier.

[0032] The differential amplifier circuit in this embodiment is a high-impedance input differential amplifier circuit. The high-impedance input differential amplifier circuit can effectively suppress common-mode noise and reduce noise. Compared with the method of adding a current mirror, this implementation has less impact on acquisition accuracy and dynamic range.

[0033] Step 3: Determine the limit parameters based on the amplification process at each level, and determine the i-th electrical signal as the target electrical signal based on the limit parameters; i=1, 2, ..., n+1; when n=1, the method for determining the limit parameters includes: Determining a first circuit parameter and a first circuit gain parameter based on the maximum reflected light power and the photoelectric conversion efficiency of the reflected light signal; the first circuit gain parameter is a circuit gain parameter between the node where the electrical signal is emitted and the first node; the first node is the output end of the first amplifier; Determining a maximum saturated reflected light intensity of the second circuit based on the output accuracy of the first circuit; presetting a minimum voltage threshold and a minimum resolution threshold, wherein the maximum saturated reflected light intensity satisfies that the output voltage of the first circuit is greater than or equal to the minimum voltage threshold, and the output voltage resolution of the second circuit is greater than or equal to the minimum resolution threshold; Under the maximum saturated reflected light intensity of the second circuit, a second circuit gain parameter is determined; the second circuit gain parameter is the circuit gain from the first node to the second node; the second node is the output end of the second amplifier; obtaining an output voltage value of the first circuit when the second circuit has maximum saturated reflected light; The limit parameter is obtained by subtracting the reserved redundant voltage from the output voltage value of the first circuit.

[0034] Methods for determining target electrical signals include: When the first electrical signal is greater than or equal to the limit parameter, the first electrical signal is used as the target electrical signal; Otherwise, the second electrical signal is used as the target electrical signal.

[0035] Next, based on adding a current mirror circuit, a transimpedance amplifier circuit, or a differential amplifier circuit to the first circuit, the limit parameters are determined respectively in combination with the above method: for Figure 7 In the case where a current mirror circuit is added to the first circuit, the voltage V1 of the first node is expressed as: V1=i*R=(η*Pi)*R; at this time, the gain parameter A1 of the first circuit is R; The voltage V2 of the second node is expressed as: V2 = V1 * (1 + R4 / R3) = (η * Pi) * R * B1, and the second circuit gain parameter B1 = 1 + R4 / R3; where η represents the photoelectric conversion efficiency and is set to 1 in this embodiment; Pi represents the maximum reflected light power of the reflected light signal; the time constant τ of the filter is selected according to the noise level of the entire circuit. For example, the resistors R2 and R5 can be 1 k ohm, the capacitors C1 and C2 can be 0.01 uF, and τ = 10 us, which can effectively filter out low-frequency noise.

[0036] Based on the maximum reflected light power and photoelectric conversion efficiency of the reflected light signal to be measured, appropriate first circuit parameters and first circuit gain parameters are determined. The first circuit gain parameter is the circuit gain parameter between the electrical signal emission node and the first node (i.e., point V1 in the figure) at the maximum reflected light power of the reflected light signal. In this embodiment, assuming that the maximum reflected light of the reflected light signal to be measured is -13dBm (50uW) and the conversion efficiency is 1mA / mW, the photocurrent of the maximum reflected light signal is i = 50uW * 1mA / mW = 50uA, and the resistance R = 2.5V / 50uA = 50kΩ.

[0037] The maximum saturated reflected light intensity of the second circuit is determined primarily by the monitoring accuracy of the first circuit's output. In this example, -26dBm was chosen as the maximum saturated reflected light intensity for the second circuit, taking into account the good monitoring accuracy of the first stage at -26dBm and the good monitoring accuracy of the second circuit at -43dBm. This value can be adjusted based on actual application needs. For example, if -26dBm (2.5uW) is chosen as the saturation point of the second circuit, the gain of the second circuit is determined as: V2 = (η*Pi) * R * B1; B1 = V2 / (η*Pi * R) = 2.5V / (2.5uA * 50kΩ) = 20.

[0038] In order to verify that both sections have good accuracy and acquisition range, this embodiment has carried out simulation tests, and the simulation calculation results are as follows: Figure 10 and Figure 11 As shown, Figure 10 and Figure 11 Assuming B1 = 20, the simulation data shows that when the power of the reflected light signal is high (-13dBm to -26dBm in the figure), the output voltage of the first circuit is greater than 125mV, meeting the minimum voltage threshold, and the voltage difference per dB is greater than 25mV. When the power of the reflected light signal is low (-26dBm to -43dBm in the figure), the output voltage of the second circuit is greater than 50mV, and the voltage difference per dB is greater than 10mV. A 10-bit analog-to-digital converter generally has 9 effective bits, and the minimum resolution voltage is 2.5V / 511=4.89mV, which meets the minimum resolution threshold. Therefore, the voltage values ​​of the above two segments can be accurately acquired.

[0039] for Figure 9 In the case where a transimpedance amplifier circuit is added to the first circuit, the voltage V1 at the first node is expressed as: V1 = i*R*A2 = (η*Pi)*(A2*R); where R1 = R7 and R6 = R8; the gain parameter of the first circuit is A2 = R6 / R1; the voltage V2 at the second node is expressed as: V2 = V1*B2 = (η*Pi)*(A2*R)*B2, and the gain parameter of the second circuit is B2 = 1+R4 / R3; for Figure 8 In the case of adding a differential amplifier circuit to the first circuit, the voltage V1 of the first node is expressed as: V1 = i*R*A3 = (η*Pi)*(A3*R); where R11 = R12, R13 = R15; R14 = R16; the circuit gain parameter is A3 R; the circuit gain A3 = (1+2*R11 / R10)*R14 / R13; the voltage V2 of the second node is expressed as: V2=(η*Pi)*(A3*R)*B3, the second gain parameter B3=1+R4 / R3; according to the above method, the appropriate resistor R, circuit gain A3 and second gain parameter B3 are determined, which can make the two-stage analog-to-digital converter acquisition meet the dynamic range of >30dB; similarly, if the maximum photocurrent of 50uA needs to be monitored, then A3*R=2.5V / 50uA=50kΩ, if A3=10, then R=5kΩ; when the second gain parameter B3 is 20, a dynamic range greater than 30dB and better monitoring accuracy can be obtained. The simulation calculation results are as follows Figure 10 and Figure 11 shown.

[0040] Step 4: monitor the target electrical signal and issue an alarm when the target electrical signal exceeds a threshold. This includes the following methods: Preset alarm threshold A and alarm threshold B, where A>B; When Qi>A, a serious alarm signal is issued; When A>Qi>B, a general alarm signal is issued; When B>Qi, no alarm signal is generated; Among them, Qi is the target electrical signal.

[0041] When different methods are used to obtain reflected light signals, the collected electrical signals are different, and the alarm thresholds set for different electrical signals are also different; specifically: For Embodiment A, the reflected optical signal of the TM transverse magnetic mode part is collected, and the proportional relationship between the reflected optical signal of the TM transverse magnetic mode part and the reflected optical signal of the TM transverse magnetic mode part is determined according to parameters such as the optical module system structure and experience, and the intensity of the complete reflected optical signal can be monitored based on the reflected optical signal of the TM transverse magnetic mode part. Specifically, the polarization state of the reflected optical signal in the optical module link has a certain degree of randomness, and the intensity of the complete reflected optical signal cannot be accurately determined solely by the reflected optical signal of the TM transverse magnetic mode part, so there is also a certain degree of randomness in the judgment; for example, the requirement of the protocol or the link for the intensity of the reflected optical signal is A, and three thresholds are set according to experience and data (bit error rate), etc., which are the system tolerance threshold A, and two thresholds are set according to experience and data (bit error rate), etc., which are the system tolerance thresholds A and B, where B < A; if the monitored intensity of the reflected optical signal > A, there must be a problem with the link, a serious alarm is generated, the warning light turns red, and the link needs to be troubleshot; if the monitored intensity of the reflected optical signal is between A and B, there may be a problem with the link, a general alarm is generated, the warning light turns yellow, and an engineer needs to intervene and use other means to monitor the reflection, check the bit error rate to obtain the true state of the system. If the monitored intensity of the reflected optical signal < B, there may be no problem, no alarm is generated, and the warning light turns green; the alarm threshold of the target electrical signal output by the acquisition circuit can be determined according to the above rules.

[0042] For Implementation Mode B1 of Embodiment B, under this polarization control beam splitter structure, adjust the phase adjustment amounts (i.e., the phase differences of the phase shift arms) of the first phase shifter group and the second phase shifter group to traverse all polarization states of the output first optical signal; obtain the fifth optical signal corresponding to the second optical signal in all polarization states, and screen out one or more polarization states with the largest fifth optical signal as the target polarization states; monitor under the target polarization states, use the fifth optical signal output in the target polarization states as the monitoring acquisition object, and set alarm thresholds for monitoring when making subsequent alarm judgments for the first electrical signal output by the first circuit as the target electrical signal or the second electrical signal output by the second circuit as the target electrical signal.

[0043] For Implementation Mode B2 of Embodiment B, under this polarization control beam splitter structure, adjust the phase adjustment amount (i.e., the phase difference of the phase shift arm) of the phase shifter group, scan the reflected optical signal for at least a π / 2 cycle when the output first optical signal is in any polarization state, fit the trigonometric function of the reflected optical signal, and use twice the median value of the trigonometric function as the judgment object; similarly, when making subsequent alarm judgments, set corresponding alarm thresholds for monitoring for the judgment object obtained from the first electrical signal or the judgment object obtained from the second electrical signal.

[0044] Embodiment 2 This embodiment provides an optical module link defect monitoring system for implementing the optical module link monitoring method described in Example 1. The system includes: A detection module is used to obtain the reflected light signal in the optical module link and convert the reflected light signal into an electrical signal. The detection module in this embodiment includes a reflected light signal acquisition module and a photodetector. a first amplifying module, configured to perform a first-stage amplification process on the electrical signal to obtain a first electrical signal; a second amplification module, configured to perform a second-stage amplification process on the first electrical signal to obtain a second electrical signal; …; The nth amplifying module performs the n+1th stage amplification processing on the nth electrical signal to obtain the n+1th electrical signal; n≥1; A parameter determination module is used to determine the limit parameters based on the amplification processing of each level, and to determine the i-th electrical signal as the target electrical signal according to the limit parameters; i=1, 2, ..., n+1; The alarm module is used to monitor the target electrical signal and issue an alarm when the target electrical signal exceeds an alarm threshold.

[0045] It also includes a scanning module for scanning the electrical signal, and the scanning module is connected to the detection module.

[0046] Since the embodiment 1 for the B solution needs to continuously scan the reflected light signal; therefore, this embodiment is set as follows Figure 12 The scanning module shown is used for scanning, and the scanning module includes a digital-to-analog converter DAC and a sixth amplifier, the input end of the digital-to-analog converter DAC is connected to the MCU, the output end of the digital-to-analog converter DAC is connected to the positive input end of the sixth amplifier, and the negative input end of the sixth amplifier is connected to the output end of the sixth amplifier; The scanning module scans the reflected light signal with a scanning voltage range of 0 to 2.5V, a load of 150 ohms, and a maximum drive current greater than 2.5V / 150 = 16.7mA. The digital-to-analog converter (DAC) outputs a 0 to 2.5V voltage. During the scanning process, a function of the scanning voltage of the reflected light signal is obtained, and twice the value is used as the pass target.

[0047] Example 3 In the actual application of high-speed silicon photonics modules, there are mainly 4-channel coarse wavelength division CWDM-4, ​​4-channel fine wavelength division LWDM-4, ​​4-channel medium-distance DR4 and 4-channel long-distance LR4 optical modules or 2 groups of 4-channel optical modules, or 8-channel optical module structure; This embodiment is discussed with a 4-way example. Figure 13As shown, in color optical applications (coarse wavelength division CWDM and fine wavelength division LWDM), the high-speed silicon photonics module includes four reflected light signal acquisition units, each of which includes a laser and an optical chip coupler, and the four reflected light signals are collected by an acquisition circuit, wherein the acquisition circuit part mainly includes the first circuit and the second circuit in the above-mentioned embodiments 1-3; the model in each reflected light signal acquisition unit is transmitted to the wavelength division multiplexer; the reflected light signal of each wavelength is monitored in real time by the acquisition circuit, and the monitored and collected signals (target electrical signals) are Qi (i=1, 2, 3, 4); an alarm threshold A1 and an alarm threshold B1 are set; when the monitoring value (target electrical signal) Qi> the alarm threshold A1, the optical path has a serious defect; when the alarm threshold B1< the monitoring value (target electrical signal) Qi< the alarm threshold A1, the optical path has a defect, which has a significant impact on the signal transmission performance; when the monitoring value Qi< the alarm threshold B1, the reflected signal on the optical path is very small and has no impact on the signal transmission. like Figure 14 As shown in the figure, in a white light application (medium-distance DR), four light paths are coupled into the optical fiber respectively. At this time, the monitored and collected signals are Qi (i=1, 2, 3, 4). The alarm thresholds A2 and B2 are set. When the monitoring value (target electrical signal) Qi> the alarm threshold A2, the optical path has a serious defect. When the alarm threshold B2< the monitoring value (target electrical signal) Qi< the alarm threshold A2, the optical path has a defect, which has a significant impact on the signal transmission performance. When the monitoring value (target electrical signal) Qi< the alarm threshold B2, the reflected signal on the optical path is very small and has no impact on the signal transmission. Example 4 The optical module in the above embodiment supports the Common Management Interface Specification (CMIS) and monitors the reflected optical signal through the VDM observables in the specification. The multifunctional diagnostic monitoring (VDM) in the Common Management Interface Specification (CMIS) 5.0 is an optional, scalable diagnostic monitoring function that can have up to 256 VDM observables. This embodiment defines the monitoring parameter description, real-time monitoring value, alarm threshold, and alarm status of reflected light in the VDM protocol of CMIS 5.0 and above. Users can modify the threshold according to actual application conditions. Taking a four-channel optical module as an example, the monitoring of four channels of reflected light is mapped to the multi-function diagnostic monitoring VDM193 to VDM196: The definition of multi-function diagnostic monitoring VDM is shown in Table 1: Table 1 Multi-function diagnostic monitoring VDM definition

[0048] The upper four bits of the even-numbered address register in Table 1 define which group of alarm thresholds is used for the monitored value. If all four monitored values ​​are '0', it means that the 49th group of alarm thresholds are used as their common alarm threshold values. The lower four bits are '0', '1', '2', and '3', respectively, representing the monitored reflected light intensity of the first channel, the reflected light intensity of the second channel, the reflected light intensity of the third channel, and the reflected light intensity of the fourth channel.

[0049] The odd address registers are type definitions for the reflected light signal monitoring values, as shown in Table 2: Table 2 Definition of monitoring value type VDM

[0050] Table 3 Real-time monitoring value VDM definition

[0051] Table 4 Alarm threshold value VDM definition

[0052] Table 5 Alarm symbol VDM definition

[0053] Table 1 is located on page 23h, group 4 of the register; Table 3 is located on page 27h, group 4 of the register; Table 4 is located on page 2Bh of the register; and Table 5 is located on page 2Ch of the register; where 23h, 27h, 2Bh, and 2Ch are hexadecimal values.

[0054] The VDM definitions in Tables 1 to 5 above implement the determination of the monitoring value Qi of the reflected light signal (i.e., VDM193 to VDM196 defined in the VDM): When the monitoring value (target electrical signal) Qi> the alarm threshold A, there is a serious defect in the optical path and a serious alarm is generated; Alarm threshold B < monitoring value (target electrical signal) Qi < alarm threshold A, there is a general defect in the optical path, and a general alarm is generated; The monitoring value (target electrical signal) Qi is less than the alarm threshold B. The reflected signal on the optical path is very small and no alarm is generated.

[0055] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for monitoring optical module link defects, characterized in that: include: Obtain the reflected light signal in the optical module link and convert it into an electrical signal; The method for obtaining the reflected light signal comprises: a transmitting end of the optical module sends a main optical signal to the optical module link; obtaining a return optical signal returned from the optical module link, and separating the reflected light signal from the return optical signal based on a polarization control beam splitter or a polarization beam splitter; Performing a first-stage amplification process on the electrical signal to obtain a first electrical signal, performing a second-stage amplification process on the first electrical signal to obtain a second electrical signal, ..., performing an n+1-th-stage amplification process on the n-th electrical signal to obtain an n+1-th electrical signal; n≥1; Based on the amplification process of each level, a limit parameter is determined, and the i-th electrical signal is determined as the target electrical signal according to the limit parameter; i=1, 2, ..., n+1; The target electrical signal is monitored, and an alarm is issued when the target electrical signal exceeds an alarm threshold.

2. The optical module link defect monitoring method according to claim 1, wherein: When the reflected light signal is separated from the return light signal based on the polarization control beam splitter, the method of obtaining the reflected light signal in the optical module link includes: The transmitting end of the optical module sends a first optical signal, and the polarization control beam splitter performs a first polarization conversion on the first optical signal to obtain a second optical signal that is sent to the optical module link; The polarization control beam splitter performs a second polarization conversion on the third optical signal returned in the optical module link to obtain a fourth optical signal and a fifth optical signal; the fourth optical signal is returned to the transmitting end of the optical module; the third optical signal is in a random polarization state; the random polarization state means that the optical signal is fixed in one or more polarization states at a certain moment; The fifth optical signal is used as the reflected optical signal.

3. The optical module link defect monitoring method according to claim 1, wherein: When the reflected light signal is separated from the returned light signal based on the polarization beam splitter, the method of obtaining the reflected light signal in the optical module link includes: The transmitting end of the optical module sends a sixth optical signal to the optical module link, wherein the sixth optical signal is in the first polarization mode; obtains a seventh optical signal returned from the optical module link, performs polarization separation on the seventh optical signal to obtain an eighth optical signal and a ninth optical signal; the eighth optical signal is in the first polarization mode; and uses the ninth optical signal as the reflected optical signal.

4. The optical module link defect monitoring method according to claim 1, wherein: When n=1, the first stage amplification process is implemented based on the first circuit, and the second stage amplification process is implemented based on the second circuit; The first circuit includes: a first amplifier, a resistor R and a first analog-to-digital converter; one end of the resistor R is connected to the negative input terminal of the first amplifier, and the other end is connected to the output terminal of the first amplifier; the positive input terminal of the first amplifier is grounded; and the output terminal of the first amplifier is connected to the first analog-to-digital converter; The second circuit includes: a second amplifier, a resistor R3, a resistor R4, and a second analog-to-digital converter; one end of the resistor R3 is grounded, and the other end is connected to the negative input terminal of the second amplifier; one end of the resistor R4 is connected to the output terminal of the second amplifier, and the other end is connected to the negative input terminal of the second amplifier; the output terminal of the second amplifier is connected to the second analog-to-digital converter; The output terminal of the first amplifier is connected to the positive input terminal of the second amplifier.

5. The optical module link defect monitoring method according to claim 4, characterized in that: Also includes: A current mirror circuit, a transimpedance amplifier circuit, or a differential amplifier circuit; the current mirror circuit, the transimpedance amplifier circuit, or the differential amplifier circuit are all connected to the input end of the first circuit; the first circuit and the second circuit both include a filter circuit, the filter circuit is arranged between the first amplifier and the first analog-to-digital converter, and the filter circuit is arranged between the second amplifier and the second analog-to-digital converter.

6. The optical module link defect monitoring method according to claim 4, characterized in that: When n=1, the methods for determining the limit parameters include: Determining a first circuit parameter and a first circuit gain parameter based on the maximum reflected light power and the photoelectric conversion efficiency of the reflected light signal; the first circuit gain parameter is a circuit gain parameter between the node where the electrical signal is emitted and the first node; the first node is the output end of the first amplifier; Determining a maximum saturated reflected light intensity of the second circuit based on the output accuracy of the first circuit; presetting a minimum voltage threshold and a minimum resolution threshold, wherein the maximum saturated reflected light intensity satisfies that the output voltage of the first circuit is greater than or equal to the minimum voltage threshold, and the output voltage resolution of the second circuit is greater than or equal to the minimum resolution threshold; Under the maximum saturated reflected light intensity of the second circuit, a second circuit gain parameter is determined; the second circuit gain parameter is the circuit gain from the first node to the second node; the second node is the output end of the second amplifier; obtaining an output voltage value of the first circuit when the second circuit has maximum saturated reflected light; The limit parameter is obtained by subtracting the reserved redundant voltage from the output voltage value of the first circuit.

7. The optical module link defect monitoring method according to claim 6, characterized in that: The method for determining the target electrical signal includes: When the first electrical signal is greater than or equal to the limit parameter, the first electrical signal is used as the target electrical signal; Otherwise, the second electrical signal is used as the target electrical signal.

8. The optical module link defect monitoring method according to claim 7, characterized in that: monitoring the target electrical signal and issuing an alarm when the target electrical signal exceeds an alarm threshold; Includes methods: Preset alarm threshold A and alarm threshold B, where A>B; When Qi>A, a serious alarm signal is issued; When A>Qi>B, a general alarm signal is issued; When B>Qi, no alarm signal is generated; Among them, Qi is the target electrical signal.

9. The optical module link defect monitoring method according to any one of claims 1 to 8, characterized in that: The optical module supports the Common Management Interface Specification (CMIS) and implements monitoring of the reflected optical signal through an observable variable (VDM) in the specification.

10. An optical module link defect monitoring system, characterized in that: For implementing the optical module link monitoring method according to any one of claims 1 to 9, the system comprises: The detection module is used to obtain the reflected light signal in the optical module link and convert the reflected light signal into an electrical signal; a first amplifying module, configured to perform a first-stage amplification process on the electrical signal to obtain a first electrical signal; a second amplification module, configured to perform a second-stage amplification process on the first electrical signal to obtain a second electrical signal; …； The nth amplifying module performs the n+1th stage amplification processing on the nth electrical signal to obtain the n+1th electrical signal; n≥1; A parameter determination module is used to determine the limit parameters based on the amplification processing of each level, and to determine the i-th electrical signal as the target electrical signal according to the limit parameters; i=1, 2, ..., n+1; The alarm module is used to monitor the target electrical signal and issue an alarm when the target electrical signal exceeds an alarm threshold.

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