An optical module integrated with OTDR and delay adaptive compensation function and a working method thereof

Abstract

The application discloses an optical module integrated with OTDR and delay adaptive compensation functions and a working method thereof, realizes closed-loop integration of link diagnosis and performance optimization, combines the link state sensing capability of optical time domain reflection with the measurement and compensation capability of transmission delay in a single optical module, so that the module can not only locate fiber faults, but also directly optimize the transmission performance of the module by using the diagnosis information, and forms an intelligent closed loop of "sensing-decision-execution". Nanosecond-level real-time delay compensation is realized at the physical layer source; by integrating a signal processing and FPGA unit in the optical module, the optical fiber physical length measured based on OTDR or the delay change monitored in real time is directly used to quickly and adaptively adjust the digital domain delay of the service data stream. This sinks the compensation point to the link closest to the physical link, thereby significantly improving the real-time performance and precision of the compensation and meeting the harsh requirements of high-precision time synchronization scenes.

Description

Technical Field

[0001] This invention relates to the field of optical fiber communication technology, specifically to an optical module and its working method that have the capabilities of optical fiber link diagnosis, fault location and dynamic compensation for transmission delay. Background Technology

[0002] As the cornerstone of modern information society, the physical state and transmission performance of fiber optic links directly determine the stability and reliability of communication systems. Optical Time Domain Reflectometry (OTDR) technology is a core method for diagnosing fiber optic link faults (such as breaks and bends) and monitoring losses. Traditionally, OTDRs have been used as standalone handheld instruments, unable to achieve online, real-time link monitoring, resulting in low maintenance efficiency. Therefore, the industry has proposed a solution that integrates OTDR functionality into optical modules to achieve online intelligent maintenance of fiber optic links.

[0003] For example, Huawei Technologies Co., Ltd. disclosed an optical module whose control unit can switch between OTDR mode and service mode. It receives and analyzes the OTDR signal returned from the optical fiber through a first optical receiving unit for optical signal transmission analysis. Accelink Technologies Co., Ltd. disclosed a DWDM ROF module with OTDR functionality, which integrates an FPGA (Field-Programmable Gate Array) to generate OTDR pulse electrical signals and analyze the reflected signals. In addition, Qingdao Xinghang Optoelectronic Technology Co., Ltd., Rizhao Airui Optoelectronic Technology Co., Ltd., and others have also disclosed various optical module designs integrating OTDR functionality. These existing technologies effectively solve the problems of miniaturization, integration, and online monitoring of OTDR functionality, but their functional positioning is still limited to link fault diagnosis and status monitoring.

[0004] On the other hand, in applications highly sensitive to transmission delay, such as high-precision time synchronization, 5G fronthaul, and industrial control, the fixed transmission delay introduced by fiber optic links and its environmental fluctuations become key factors affecting system performance. Various measurement and compensation schemes for fiber optic transmission delay exist in existing technologies. For example, ZTE Corporation has disclosed an automatic compensation method for asymmetric delay in medium- and long-distance fiber optic transmission; Fujian Jingao Communication Technology Co., Ltd. has disclosed a delay compensation method for fiber optic transmission systems, which achieves signal synchronization by calculating and compensating for the total delay value of different optical remote unit paths. In the field of higher-precision fiber optic time transfer, existing technologies typically combine FPGAs and phase-locked loop (PLL) phase shifters to achieve wide-range, high-resolution delay control. However, most of these delay compensation technologies exist as independent system-level solutions or devices, with their measurement methods (such as timestamp-based protocols) and compensation execution units (such as upper-layer switching equipment or dedicated synchronization equipment) separated from the optical modules that function as physical layer transceivers.

[0005] In summary, the existing technology mainly has the following problems and shortcomings:

[0006] (1) Functional fragmentation and failure to form a closed loop: Existing optical modules that integrate OTDR function only use the OTDR unit to output diagnostic information such as link loss and event point location, which is "only sensing, not executing". It fails to further convert the key information of the physical length of the optical fiber link accurately measured by the OTDR into optical fiber transmission delay parameters and use it to drive real-time performance compensation.

[0007] (2) Compensation lag and slow response speed: The delay compensation scheme independent of the optical module has a long closed-loop path for measurement, calculation and compensation. The signal needs to be processed by multiple levels of equipment, which cannot achieve real-time and adaptive compensation at the nanosecond or even picosecond level, and it is difficult to meet the stringent requirements of ultra-low latency application scenarios.

[0008] (3) The system is complex and has low integration: The link diagnosis (OTDR) and performance optimization (delay compensation) are implemented by different devices, which increases the system complexity, cost and power consumption, and is not conducive to the miniaturization and deployment convenience of the devices.

[0009] Therefore, there is an urgent need in this field for a highly integrated solution that can deeply integrate the real-time diagnostic capability of fiber optic links with the adaptive compensation capability for transmission delay into a single optical module, thereby achieving intelligent closed-loop management of the link that is both "knowable and controllable". Summary of the Invention

[0010] This invention aims to overcome the shortcomings of existing technologies and provide an optical module integrating OTDR and latency adaptive compensation functions, as well as its operating method. Its purpose is to solve the following technical problems:

[0011] (1) Achieve closed-loop integration of link diagnosis and performance optimization: deeply integrate the link status perception capability of optical time domain reflectance (OTDR) with the measurement and compensation capability of transmission delay into a single optical module, so that the module can not only locate fiber faults, but also directly optimize its own transmission performance using diagnostic information, forming an intelligent closed loop of "perception-decision-execution".

[0012] (2) Achieve nanosecond-level real-time delay compensation at the physical layer source: By integrating signal processing and FPGA units inside the optical module, the service data stream can be rapidly and adaptively adjusted in the digital domain based directly on the physical length of the optical fiber measured by OTDR or the delay changes monitored in real time. This pushes the compensation point down to the link closest to the physical link, thereby significantly improving the real-time performance and accuracy of the compensation and meeting the stringent requirements of scenarios such as high-precision time synchronization.

[0013] (3) Provide a highly integrated and low-complexity solution: Through the high integration of the above functions, the system complexity, high cost and inconvenient deployment caused by using independent OTDR instruments and external delay compensation equipment are avoided, the network architecture is simplified, and the unity of intelligent operation and maintenance and high-performance transmission is achieved.

[0014] The technical solution of the present invention is: an optical module integrating OTDR and delay adaptive compensation functions, comprising an optical transmitting component, a miniature OTDR detection unit, an optical receiving component, and an integrated signal processing and FPGA unit;

[0015] The optical emitting component includes a laser driver and a first laser, used to emit high-speed service optical signals in normal service mode;

[0016] The miniature OTDR detection unit and the optical emitting component are optically coupled through an internal optical splitter; the miniature OTDR detection unit includes a pulse generating circuit and a driving and light source module; the driving and light source module includes a second laser capable of emitting a wavelength different from the service light wavelength, the second laser being driven by the pulse generating circuit to emit low-power test light pulses; during a preset maintenance time window or service idle period, the FPGA issues a command, and the pulse generating circuit drives the second laser to emit test light pulses;

[0017] Both the service optical signal and the test optical pulse are injected into the optical fiber link connected to the optical module through an optical splitter;

[0018] The optical receiving component includes a photodetector and a transimpedance amplifier, used to receive service optical signals from the optical fiber link and convert them into electrical signals;

[0019] The integrated signal processing and FPGA unit includes three functional sub-modules: a reflection signal analysis module, a delay measurement module, and an adaptive compensation module.

[0020] The input of the reflection signal analysis module is connected to a high-speed analog-to-digital converter (ADC). This ADC specifically samples the backscattered light signal generated by Rayleigh scattering and Fresnel reflection (from breakpoints and connectors) in the optical fiber and returning along the original path. This returned backscattered light signal is guided by the same optical splitter to an OTDR receiving photodetector for photoelectric conversion. The specific working principle of the reflection signal analysis module is as follows: the FPGA records the precise emission time t0 of the test light pulse and performs digital averaging, logarithmic transformation, and other processing on the reflection signal sampled by the ADC to form an event curve; by detecting the reflection peak on the event curve and recording its arrival time t1, according to the formula... Where c is the speed of light in a vacuum and n is the refractive index of the optical fiber, the location of the fault point is accurately calculated, and the total physical length L of the optical fiber link is obtained at the same time.

[0021] The delay measurement module directly receives the total fiber optic link length L output from the reflection signal analysis module, and fixes the delay according to the formula. Calculate the theoretical transmission delay of the fiber optic link itself;

[0022] The adaptive compensation module receives delay data (the change in T_fiber or T_total, ΔT) from the delay measurement module. Its core is a deeply configurable digital delay line implemented by FPGA logic. For the transmission path, before sending the service data to the laser driver, the FPGA writes it into a first-in-first-out buffer and uses a delay control state machine to precisely control the readout clock or enable signal of this buffer according to compensation requirements, thereby achieving pre-delay of the transmitted signal. For the reception path, the FPGA performs similar digital delay line processing on the service data sampled from the transimpedance amplifier's subsequent ADC stage to achieve reception calibration.

[0023] Furthermore, to cope with dynamic changes, the delay measurement module can also measure the actual total end-to-end transmission delay T_total by analyzing the timestamp information carried in the service signal (such as 1588 PTP messages) and comparing it with the local clock.

[0024] Furthermore, the accuracy of the compensation in the adaptive compensation module is jointly guaranteed by the FPGA's system clock cycle, which can reach hundreds of picoseconds, and the fine-tuning digital delay unit based on the phase interpolator.

[0025] Furthermore, the first laser is a directly modulated laser or an electroabsorption modulated laser.

[0026] Furthermore, the second laser is a side-emitting laser or a vertical-cavity surface-emitting laser.

[0027] Furthermore, it also includes a management interface, which is a standard I2C or MDIO interface, used to communicate with the host device, report OTDR diagnostic results (event points, losses, lengths), current delay values ​​and compensation status, and receive configuration instructions (such as OTDR trigger cycles).

[0028] This invention also provides a method for operating an optical module that integrates OTDR and latency adaptive compensation functions, the specific steps of which are as follows:

[0029] Step S1: Periodic link diagnosis and measurement;

[0030] The optical module automatically enters diagnostic mode upon power-on initialization or according to the host configuration cycle; the FPGA controls the miniature OTDR detection unit to emit a series of test light pulses, and at the same time starts the reflection signal analysis module to perform high-speed sampling and data processing.

[0031] Step S2: Calculation of fiber optic length and fault location;

[0032] The reflection signal analysis module completes event curve analysis, accurately calculates the total physical length L of the fiber optic link, and identifies and locates the position and loss of events such as breakpoints and connectors, generating structured diagnostic data.

[0033] Step S3: Calculate transmission delay;

[0034] The delay measurement module calculates the theoretical fiber delay T_fiber based on the length L obtained in step S2 and the preset fiber refractive index n;

[0035] Step S4: Real-time adaptive compensation;

[0036] The adaptive compensation module converts the delay value obtained in step S3 into specific digital delay line control parameters; the FPGA then dynamically adjusts the depth of the digital delay lines in the transmission and / or reception directions on the service data flow path to complete real-time compensation for transmission delay.

[0037] Step S5: Data reporting and status synchronization;

[0038] The optical module reports the diagnostic results of step S2 and the delay measurement value of step S3 to the host network management system through the management interface; the entire measurement-compensation process can run periodically without interruption of services, realizing closed-loop adaptive control.

[0039] Furthermore, in step S3, transmission delay calculation, the delay measurement module simultaneously monitors the service channel and calculates the actual dynamic delay using a timestamp protocol.

[0040] The beneficial effects of this invention are as follows: Compared with the prior art, the optical module and method integrating OTDR and delay adaptive compensation functions provided by this invention have the following significant advantages and positive effects:

[0041] 1. It achieves a closed-loop unification of operation and maintenance diagnosis and performance optimization, which greatly improves operation and maintenance efficiency and system intelligence.

[0042] In existing technologies, OTDR functionality is only used to output diagnostic reports, while delay compensation relies on external systems, making the two separate processes. This invention integrates fault location, length measurement, delay calculation, and compensation into a single module, forming an autonomous "measurement-calculation-compensation" closed loop. This enables the optical module not only to detect link breaks (e.g., at 15.3 km), but also to immediately and automatically adjust signal timing based on the measured link length, stabilizing transmission delay at the target value. Network maintenance personnel are transformed from passively responding to multiple devices to an integrated "problem location + compensation" solution automatically reported by the receiving module, achieving a leap from "monitoring" to "self-healing."

[0043] 2. High-precision, low-latency delay compensation was achieved at the physical layer source, meeting the stringent requirements of synchronous applications.

[0044] Traditional system-level latency compensation schemes require signal processing through multiple stages, introducing additional jitter and resulting in slow response. This invention places the compensation execution point within the FPGA module, closest to the physical fiber optic link. By precisely measuring the physical length of the fiber optic cable using an OTDR and calculating the latency value, the digital delay line within the FPGA is directly driven for compensation, avoiding the uncertainties and delays introduced by traditional protocol stack calculations. This enables compensation accuracy down to the nanosecond or even picosecond level, with a response speed in the millisecond range, providing reliable physical layer protection for applications extremely sensitive to latency and jitter, such as 5G fronthaul, financial transactions, and precise industrial control.

[0045] 3. The system architecture has been simplified, reducing overall cost and complexity.

[0046] This invention eliminates the need for external, standalone OTDR instruments and independent delay compensation devices. No additional slots, power supplies, or management interfaces are required for these independent functions within the equipment rack. This not only saves on hardware procurement costs and reduces system power consumption but also reduces cabling complexity and potential points of failure. For large data centers or communication networks, this highly integrated design can significantly save server room space, simplify operations and maintenance, and achieve a better total cost of ownership.

[0047] 4. Improved network reliability and service experience.

[0048] This invention supports continuous, periodic monitoring and adaptive adjustment of fiber optic link status and transmission latency. The system can detect progressive degradation of the fiber (such as increased bending loss) in advance and provide early warnings or compensation before it affects service performance (such as latency fluctuations exceeding a threshold), transforming passive repair into proactive prevention. For high-value services, this capability ensures continuous stability of transmission quality, reduces the risk of service interruption or performance degradation due to changes in link physical characteristics, and thus improves the overall service level agreement (SLA) assurance level.

[0049] 5. It provides an innovative underlying support solution for high-precision time synchronization.

[0050] In scenarios requiring high-precision time synchronization, fiber asymmetry and delay fluctuations are the main sources of error. The "physical length measurement + real-time compensation" mechanism provided by this invention offers a high-precision a priori value or real-time correction reference with a first-order fixed delay for time synchronization protocols (such as IEEE 1588). This mechanism can directly reduce the most significant delay uncertainty at the physical layer, complementing the protocol layer correction and potentially leading to a more precise and robust synchronization system. Attached Figure Description

[0051] Figure 1 This is a schematic diagram of the internal functional modules of an optical module integrating OTDR and delay adaptive compensation functions according to an embodiment of the present invention. The diagram illustrates the core internal architecture of the optical module of the present invention. Solid arrows represent the main service data flow or control signal flow, while dashed arrows represent the OTDR test and reflection signal paths.

[0052] Figure 2 This is an embodiment of the present invention based on Figure 1 The flowchart shows the working method of the optical module for adaptive delay compensation. Detailed Implementation

[0053] The present invention will now be further described with reference to the accompanying drawings.

[0054] This invention provides an optical module integrating OTDR and delay adaptive compensation functions and its working method, aiming to solve the problems of functional fragmentation, compensation lag and system complexity in the prior art through the following new technical means and measures.

[0055] I. For example Figure 1 The optical module structure technical solution shown

[0056] The optical module of this invention comprises: an optical transmitting component, a miniature OTDR detection unit, an optical receiving component, an integrated signal processing and FPGA unit, and a management interface. The connection relationships and working principles of each component are as follows:

[0057] Optical emission components: These include laser drivers and directly modulated lasers or electroabsorption modulated lasers. Their core task is to transmit high-speed service optical signals during normal operation.

[0058] Miniature OTDR detection unit: This is one of the key innovative components. It is optically coupled to the optical emitting assembly via an internal optical splitter / coupler. This unit specifically includes:

[0059] Pulse generation circuit: controlled by FPGA, it generates narrow electrical pulses with low duty cycle and adjustable width (typically ranging from 10 ns to 1 μs).

[0060] Drive and Light Source: A separate, low-power edge-emitting laser or vertical-cavity surface-emitting laser with a wavelength different from the service light wavelength (e.g., service light is 1310nm / 1550nm, OTDR probe light can be selected in the 1625nm or 1650nm band) to avoid interference in the same wavelength band. This laser is driven by a pulse generation circuit to emit low-power test light pulses.

[0061] Working principle: During a preset maintenance time window or idle period, the FPGA issues a command, and the pulse generation circuit drives the OTDR-specific laser to emit a test pulse. This pulse is injected into the fiber optic link connected to the optical module through an optical splitter.

[0062] Optical receiving component: including photodetector and transimpedance amplifier, used to receive service optical signals from fiber optic link and convert them into electrical signals.

[0063] Integrated Signal Processing and FPGA Unit: This is the core integrated functional component, integrating analog-to-digital conversion, digital signal processing, and programmable logic. It comprises three functional sub-modules, all implemented within the FPGA's internal logic or in a closely cooperating processor:

[0064] Reflection Signal Analysis Module: This module's input is connected to a high-speed analog-to-digital converter (ADC). This ADC specifically samples the backscattered light signal generated by Rayleigh scattering and Fresnel reflection (from breakpoints and connectors) in the optical fiber and returning along the original path. This returned light signal is guided through the same optical splitter to a dedicated OTDR receiving photodetector for photoelectric conversion. The module's working principle is as follows: The FPGA records the precise transmission time t0 of the test pulse and performs digital averaging, logarithmic transformation, and other processing on the reflected signal sampled by the ADC to form an event curve. By detecting the reflection peak on the curve and recording its arrival time t1, the signal is analyzed according to the formula... (Where c is the speed of light in a vacuum and n is the refractive index of the optical fiber) Accurately calculate the location of the fault point and simultaneously obtain the total physical length L of the optical fiber link.

[0065] Delay Measurement Module: This module directly receives the total fiber optic link length L from the reflection signal analysis module. It then calculates the fixed delay based on a formula. This module calculates the theoretical transmission delay of the fiber optic link itself. To cope with dynamic changes, it can also analyze the timestamp information carried in the service signal (such as 1588 PTP messages), compare it with the local clock, and measure the actual end-to-end total transmission delay T_total.

[0066] Adaptive Compensation Module: This is another key innovative component. This module receives delay data (the change in T_fiber or T_total, ΔT) from the delay measurement module. At its core is a deeply configurable digital delay line implemented by FPGA logic. For the transmit path, the FPGA writes the service data into a first-in-first-out buffer before sending it to the laser driver. A delay control state machine precisely controls the readout clock or enable signal of this buffer according to compensation requirements, thus achieving pre-delay of the transmit signal. For the receive path, the FPGA performs similar digital delay line processing on the service data sampled from the transimpedance amplifier's subsequent ADC stage to achieve receive calibration. The accuracy of the compensation is guaranteed by the FPGA's system clock cycle (up to hundreds of picoseconds) and fine-tuning digital delay units (such as those based on phase interpolators).

[0067] Management interface: A standard I2C or MDIO interface is used to communicate with the host device, report OTDR diagnostic results (event points, loss, length), current delay value and compensation status, and receive configuration instructions (such as OTDR trigger cycle).

[0068] II. Figure 2 The working method and technical solution shown

[0069] The working method of the above-mentioned optical module includes the following steps:

[0070] S1: Periodic Link Diagnosis and Measurement. The optical module automatically enters diagnostic mode upon power-on initialization or according to the host configuration cycle. The FPGA controls the miniature OTDR detection unit to emit a series of test light pulses, while simultaneously activating the reflection signal analysis module for high-speed sampling and data processing.

[0071] S2: Fiber optic length and fault location calculation. The reflection signal analysis module performs event curve analysis, accurately calculates the total physical length L of the fiber optic link, and identifies and locates the position and loss of events such as breakpoints and connectors, generating structured diagnostic data.

[0072] S3: Transmission Delay Calculation. The delay measurement module calculates the theoretical fiber delay T_fiber based on the length L obtained in step S2 and the preset fiber refractive index n. Optionally, the module simultaneously monitors the service channel and calculates the actual dynamic delay using a timestamp protocol.

[0073] S4: Real-time Adaptive Compensation. The adaptive compensation module converts the delay value (or the deviation ΔT from the target value) obtained in step S3 into specific digital delay line control parameters. The FPGA then dynamically adjusts the depth of the digital delay lines in the transmission and / or reception directions along the service data flow path to complete real-time compensation for transmission delay.

[0074] S5: Data Reporting and Status Synchronization. The optical module reports the diagnostic results of step S2 and the delay measurement value of step S3 to the host network management system through the management interface. The entire "measurement-compensation" process can run periodically without service interruption, realizing closed-loop adaptive control.

[0075] III. Key Points of the Invention

[0076] 1) Deep integration of functions and closed-loop control: For the first time, the micro OTDR detection unit, integrated signal processing and FPGA unit (including analysis, measurement and compensation sub-modules) are integrated into the optical module, which makes the OTDR evolve from a simple diagnostic tool into a key sensor that provides accurate physical layer input for delay compensation, forming a closed-loop system of self-sensing, self-decision-making and self-execution.

[0077] 2) Delay tracing based on physical length measurement: It is proposed to use the physical length of the optical fiber link, which is accurately measured by OTDR, as the most direct and reliable basis for calculating fixed transmission delay, providing traceable underlying physical parameters for high-precision time synchronization.

[0078] 3) Real-time digital compensation mechanism within the FPGA module: An adaptive compensation module is creatively implemented in the FPGA inside the optical module. Through a dynamically configurable digital delay line, the high-speed service data stream is adjusted in real time with nanosecond-level precision. The compensation action is placed at the physical layer transceiver source, achieving extremely low compensation latency and extremely high response speed.

[0079] 4) Integrated Intelligent Optical Module Architecture for "Perception-Compensation": This invention defines a new intelligent optical module architecture that not only has the ability to perceive link status, but also has the ability to autonomously optimize transmission performance based on perception results, thereby significantly improving the autonomy and reliability of optical modules in complex networks.

[0080] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An optical module integrating OTDR and delay adaptive compensation functions, characterized in that: It includes an optical transmitting component, a miniature OTDR detection unit, an optical receiving component, and an integrated signal processing and FPGA unit; The optical emitting component includes a laser driver and a first laser, used to emit high-speed service optical signals in normal service mode; The miniature OTDR detection unit and the optical emitting component are optically coupled through an internal optical splitter; the miniature OTDR detection unit includes a pulse generating circuit and a driving and light source module; the driving and light source module includes a second laser capable of emitting a wavelength different from the service light wavelength, the second laser being driven by the pulse generating circuit to emit low-power test light pulses; during a preset maintenance time window or service idle period, the FPGA issues a command, and the pulse generating circuit drives the second laser to emit test light pulses; Both the service optical signal and the test optical pulse are injected into the optical fiber link connected to the optical module through an optical splitter; The optical receiving component includes a photodetector and a transimpedance amplifier, used to receive service optical signals from the optical fiber link and convert them into electrical signals; The integrated signal processing and FPGA unit includes three functional sub-modules: a reflection signal analysis module, a delay measurement module, and an adaptive compensation module. The input of the reflection signal analysis module is connected to a high-speed analog-to-digital converter (ADC). This ADC specifically samples the backscattered light signal generated by Rayleigh scattering and Fresnel reflection in the optical fiber and returning along the original path. This returned backscattered light signal is guided by the same optical splitter to an OTDR receiving photodetector for photoelectric conversion. The specific working principle of the reflection signal analysis module is as follows: the FPGA records the precise emission time t0 of the test light pulse and performs digital averaging and logarithmic transformation on the reflection signal sampled by the ADC to form an event curve; by detecting the reflection peak on the event curve and recording its arrival time t1, the reflection signal is analyzed according to the formula... Where c is the speed of light in a vacuum and n is the refractive index of the optical fiber, the location of the fault point is accurately calculated, and the total physical length L of the optical fiber link is obtained at the same time. The delay measurement module directly receives the total fiber optic link length L output from the reflection signal analysis module, and fixes the delay according to the formula. Calculate the theoretical transmission delay of the fiber optic link itself; The adaptive compensation module receives delay data from the delay measurement module; At its core is a deeply configurable digital delay line implemented by FPGA logic. For the transmission path, before sending the service data to the laser driver, the FPGA writes it into a first-in-first-out buffer and uses a delay control state machine to precisely control the readout clock or enable signal of the buffer according to the compensation requirements, thereby achieving pre-delay of the transmitted signal. For the reception path, the FPGA performs digital delay line processing on the service data sampled from the transimpedance amplifier's ADC stage to achieve reception calibration. The delay measurement module can also analyze the timestamp information carried in the service signal and compare it with the local clock to measure the actual total transmission delay T_total from end to end. The accuracy of the compensation in the adaptive compensation module is guaranteed by the FPGA's system clock cycle, which can reach hundreds of picoseconds, and the fine-tuning digital delay unit based on the phase interpolator.

2. The optical module integrating OTDR and delay adaptive compensation functions according to claim 1, characterized in that: The first laser is a direct-modulated laser or an electro-absorption modulated laser.

3. The optical module integrating OTDR and delay adaptive compensation functions according to claim 1, characterized in that: The second laser is an edge-emitting laser or a vertical-cavity surface-emitting laser.

4. The optical module integrating OTDR and delay adaptive compensation functions according to claim 1, characterized in that: It also includes a management interface, which is a standard I2C or MDIO interface, used to communicate with the host device, report OTDR diagnostic results, current latency value and compensation status, and receive configuration instructions.

5. The operating method of an optical module integrating OTDR and delay adaptive compensation functions as described in any one of claims 1-4, characterized in that, The specific steps are as follows: Step S1: Periodic link diagnosis and measurement; The optical module automatically enters diagnostic mode upon power-on initialization or according to the host configuration cycle; the FPGA controls the miniature OTDR detection unit to emit a series of test light pulses, and at the same time starts the reflection signal analysis module to perform high-speed sampling and data processing. Step S2: Calculation of fiber optic length and fault location; The reflection signal analysis module completes event curve analysis, accurately calculates the total physical length L of the fiber optic link, identifies and locates the location and loss of breakpoints and connector events, and generates structured diagnostic data. Step S3: Calculate transmission delay; The delay measurement module calculates the theoretical fiber delay T_fiber based on the length L obtained in step S2 and the preset fiber refractive index n; Step S4: Real-time adaptive compensation; The adaptive compensation module converts the delay value obtained in step S3 into specific digital delay line control parameters; the FPGA then dynamically adjusts the depth of the digital delay lines in the transmission and / or reception directions on the service data flow path to complete real-time compensation for transmission delay. Step S5: Data reporting and status synchronization; The optical module reports the diagnostic results of step S2 and the delay measurement value of step S3 to the host network management system through the management interface; the entire measurement-compensation process can run periodically without interruption of services, realizing closed-loop adaptive control.

6. The operating method of an optical module integrating OTDR and delay adaptive compensation functions according to claim 5, characterized in that: In step S3, transmission delay calculation, the delay measurement module simultaneously monitors the service channel and calculates the actual dynamic delay using the timestamp protocol.

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