Method, device and equipment for suppressing polarization state in optical fiber link and storage medium thereof

Abstract

The application discloses a polarization state suppression method and device in an optical fiber link, equipment and a storage medium thereof, and relates to the technical field of data transmission. The method comprises the following steps: performing power detection on a received optical signal to obtain an auxiliary power value; based on the auxiliary power value, obtaining a current position of a Stokes vector of the optical signal on a Poincare sphere; based on the current position, determining a polarization rotation angle required for rotating the Stokes vector to power balance of X polarization and Y polarization; and based on the polarization rotation angle, performing polarization state adjustment on the optical signal. That is, by indirectly representing polarization state changes by using the auxiliary power value, the receiving end can realize fast perception and compensation of polarization imbalance without the need of additionally introducing high-complexity polarization tracking hardware or a high-speed feedback loop, so that the optical signal can always maintain a good polarization matching state, and the risk of bit error caused by polarization state disturbance can be effectively suppressed without increasing system power consumption and hardware complexity.

Description

Technical Field

[0001] This application relates to the field of data transmission technology, and in particular to methods, apparatus, devices and storage media for suppressing polarization states in optical fiber links. Background Technology

[0002] To improve data transmission rates within data centers and to achieve higher spectral efficiency and stronger channel compensation through higher-order modulation and coherent detection, coherent communication is typically introduced into short-range optical interconnects.

[0003] Currently, to reduce the complexity and power consumption of the hardware required for coherent communication, coherent detection in coherent communication is usually zero-difference coherent detection. That is, at the transmitting end, the same optical carrier is split into two beams, which are used as the transmission signal light and the local oscillator light respectively, thereby achieving coherent detection at the receiving end without the need for a separate local oscillator. However, in optical fiber lines for optical interconnection, the local oscillator light exhibits a random polarization state, and changes in this random polarization state can affect the performance of data centers, thereby causing a higher bit error rate.

[0004] The above content is only used to help understand the technical solution of this application and does not represent an admission that the above content is prior art. Summary of the Invention

[0005] The main objective of this application is to provide a method, apparatus, device, and storage medium for suppressing polarization states in optical fiber links, aiming to solve the technical problem that the local oscillator light in optical interconnect optical fiber lines exhibits random polarization states, and that changes in random polarization states can affect the performance of data centers, thereby causing bit error rates.

[0006] To achieve the above objectives, this application proposes a method for suppressing polarization states in an optical fiber link, the method comprising: Power detection is performed on the received optical signal to obtain the auxiliary power value; Based on the auxiliary power value, the current position of the Stokes vector of the optical signal on the Poincaré sphere is obtained; Based on the current position, determine the polarization rotation angle required for the Stokes vector to rotate to a power balance between X-polarization and Y-polarization; The polarization state of the optical signal is adjusted based on the polarization rotation angle.

[0007] In one embodiment, the auxiliary power value includes a first transmitted light power, a reflected light power, and a second transmitted light power; The step of performing power detection on the received optical signal to obtain an auxiliary power value includes: The received optical signal is split to obtain a first split signal when the angle between the optical signal and the preset baseline is zero, and a second split signal when the angle is a preset angle. The first transmitted light power is obtained by detecting the transmitted light power of the first spectral signal, and the reflected light power is obtained by detecting the reflected light power. The transmitted light power of the second spectral signal is detected to obtain the second transmitted light power.

[0008] In one embodiment, the step of obtaining the current position of the Stokes vector of the optical signal on the Poincaré sphere based on the auxiliary power value includes: Based on the first transmitted light power and the reflected light power, the X-polarization power in the X branch and the Y-polarization power in the Y branch of the optical signal after it is mapped to Stokes space are determined. The X-polarization power and the Y-polarization power are normalized to obtain the normalized power difference between the X branch and the Y branch; Based on the normalized power difference and the second transmitted light power, the current position of the Stokes vector of the optical signal on the Poincaré sphere is obtained.

[0009] In one embodiment, the step of obtaining the current position of the Stokes vector of the optical signal on the Poincaré sphere based on the normalized power difference and the second transmitted light power includes: Based on the normalized power difference, the XY polarization components of the Stokes vector in the XY plane are determined, where the XY plane is the plane formed by the X branch and the Y branch; Based on the second transmitted light power, the preset angular polarization component of the second spectral signal corresponding to the Stokes vector is determined; Determine whether the sum of the squared frequencies of the XY polarization components and the preset angular polarization components is greater than a preset threshold; If the value is greater than the preset threshold, the XY polarization component and the preset angular polarization component are normalized to obtain the current position of the Stokes vector of the optical signal on the Poincaré sphere.

[0010] In one embodiment, the step of determining the polarization rotation angle required for the Stokes vector to rotate to power balance between X-polarization and Y-polarization based on the current position includes: Based on the current position, determine whether the normalized power difference of the optical signal is zero; If the normalized power difference is zero, then the polarization rotation angle required for the Stokes vector to rotate to power balance between X-polarization and Y-polarization is determined to be zero. If the normalized power difference is not zero, then the normalized power difference being zero is used as the stopping condition for the rotation of the Stokes vector, and the required polarization rotation angle of the Stokes vector is determined.

[0011] In one embodiment, the step of determining the required polarization rotation angle of the Stokes vector by using the normalized power difference being zero as the stopping condition for the rotation of the Stokes vector includes: The polarization angle of the optical signal is determined by using the normalized power difference to be zero as the stopping condition for the Stokes vector rotation. Based on the auxiliary power value, the first optical power value of the first split signal after the optical signal is split at zero degrees is determined, and the second optical power value of the second split signal after the optical signal is split according to a preset angle is determined. The polarization direction of the optical signal is determined by comparing the first optical power value with the second optical power value and based on the magnitude of the comparison. Based on the polarization direction, the required polarization rotation angle for the Stokes vector is determined from the polarization angle.

[0012] In one embodiment, the step of determining the polarization angle of the optical signal by using the normalized power difference to be zero as the stopping condition for the Stokes vector rotation includes: The normalized power difference being zero is used as the stopping condition for the Stokes vector rotation, and the initial polarization angle of the optical signal is determined. Based on the normalized power difference, determine the amount of change in normalized power difference caused by the change in unit polarization rotation angle; Based on the change, the initial polarization angle is corrected to obtain the polarization rotation angle.

[0013] Furthermore, to achieve the above objectives, this application also proposes a polarization state suppression device in an optical fiber link, the polarization state suppression device in the optical fiber link comprising: The detection module is used to detect the power of the received optical signal and obtain an auxiliary power value; The position analysis module is used to obtain the current position of the Stokes vector of the optical signal on the Poincaré sphere based on the auxiliary power value; The determining module is used to determine, based on the current position, the polarization rotation angle required for the Stokes vector to rotate to a power balance between X-polarization and Y-polarization; The adjustment module is used to adjust the polarization state of the optical signal based on the polarization rotation angle.

[0014] Furthermore, to achieve the above objectives, this application also proposes a polarization state suppression device in an optical fiber link, the device comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, the computer program being configured to implement the steps of the polarization state suppression method in an optical fiber link as described above.

[0015] In addition, to achieve the above objectives, this application also proposes a storage medium, which is a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, it implements the steps of the method for suppressing polarization states in an optical fiber link as described above.

[0016] One or more technical solutions proposed in this application have at least the following technical effects: In a zero-difference coherent optical communication receiver, the power of the received optical signal is detected to obtain an auxiliary power value. Based on this auxiliary power value, the current position of the Stokes vector of the optical signal on the Poincaré sphere is calculated in real time. This determines the polarization rotation angle required to achieve power balance between X and Y polarizations, and the polarization state of the optical signal is dynamically adjusted accordingly. This fully utilizes the power balance characteristics of the two orthogonal X and Y branches and the geometric relationship of the Stokes vector on the Poincaré sphere to directly resolve the required polarization rotation angle, achieving random polarization state impairment compensation without any iterative process. This application indirectly characterizes polarization state changes using an auxiliary power value. Without introducing additional high-complexity polarization tracking hardware or high-speed feedback loops, the receiver can quickly sense and compensate for polarization imbalances, ensuring the optical signal maintains a good polarization matching state. This improves coherent mixing efficiency and signal-to-noise ratio, avoiding demodulation distortion caused by random polarization evolution and reducing dependence on the polarization stability of the transmitter. Without increasing system power consumption or hardware complexity, it effectively suppresses the risk of bit errors caused by polarization state disturbances. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a flowchart illustrating an embodiment of the method for suppressing polarization states in an optical fiber link according to this application. Figure 2 This is a flowchart illustrating Embodiment 2 of the method for suppressing polarization states in an optical fiber link according to this application. Figure 3 This is a flowchart illustrating Embodiment 3 of the method for suppressing polarization states in an optical fiber link according to this application. Figure 4This is a schematic diagram of the module structure of the polarization state suppression device in the optical fiber link in the embodiments of this application; Figure 5 This is a schematic diagram of the device structure of the hardware operating environment involved in the method for suppressing polarization states in an optical fiber link in the embodiments of this application.

[0020] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0021] It should be understood that the specific embodiments described herein are merely illustrative of the technical solutions of this application and are not intended to limit this application.

[0022] To better understand the technical solution of this application, a detailed description will be provided below in conjunction with the accompanying drawings and specific implementation methods.

[0023] The main solution of this application embodiment is: a data center receiver, after receiving an optical signal, performs power detection on the optical signal to obtain an auxiliary power value; based on the auxiliary power value, obtains the current position of the Stokes vector of the optical signal on the Poincaré sphere; based on the current position, determines the polarization rotation angle required for the Stokes vector to rotate to a power balance between X-polarization and Y-polarization; and based on the polarization rotation angle, adjusts the polarization state of the optical signal.

[0024] In this embodiment, for ease of description, the optical signal processor at the receiving end will be used as the execution subject in the following description.

[0025] This application provides a solution that performs power detection on the received optical signal at the zero-difference coherent optical communication receiver to obtain an auxiliary power value. Based on this auxiliary power value, the current position of the Stokes vector of the optical signal on the Poincaré sphere is calculated in real time. This determines the polarization rotation angle required to rotate the signal to a power balance state between X and Y polarizations. The polarization state of the optical signal is then dynamically adjusted accordingly. This fully utilizes the power balance characteristics of the two orthogonal X and Y branches and the geometric relationship of the Stokes vector on the Poincaré sphere to directly resolve the required polarization rotation angle, achieving random polarization state impairment compensation without any iterative process. By indirectly characterizing polarization state changes using the auxiliary power value, this application enables the receiver to quickly sense and compensate for polarization imbalances without introducing additional high-complexity polarization tracking hardware or high-speed feedback loops. This ensures the optical signal maintains a good polarization matching state, thereby improving coherent mixing efficiency and signal-to-noise ratio. It not only avoids demodulation distortion caused by random polarization evolution but also reduces dependence on the polarization stability of the transmitter. Without increasing system power consumption or hardware complexity, it effectively suppresses the risk of bit errors caused by polarization state disturbances.

[0026] It should be noted that the executing entity in this embodiment can be a computing service device with data processing, network communication, and program execution functions, such as a tablet computer, personal computer, or mobile phone, or an electronic device capable of performing the above functions, such as an optical signal processor at the receiving end. The following description uses an optical signal processor at the receiving end as an example to illustrate this embodiment and the subsequent embodiments.

[0027] Based on this, embodiments of this application provide a method for suppressing polarization states in an optical fiber link, referring to... Figure 1 , Figure 1 This is a flowchart illustrating the first embodiment of the method for suppressing polarization states in an optical fiber link according to this application.

[0028] In this embodiment, the method for suppressing the polarization state in the optical fiber link includes steps S10 to S40: Step S10: Perform power detection on the received optical signal to obtain an auxiliary power value; It should be noted that optical signals are electromagnetic waves carrying information transmitted in fiber optic links, and their polarization state can change randomly and dynamically with environmental disturbances. Power detection is the process of converting part or all of the optical power of the optical signal into an electrical signal using a photodetector, and obtaining the digital power value through analog-to-digital conversion. Auxiliary power values ​​are a set of indirect power measurements specifically designed to reconstruct the polarization state of the optical signal, including but not limited to: the first transmitted light power and reflected light power under zero-degree beam splitting, and the second transmitted light power under beam splitting at a preset angle (e.g., 45°).

[0029] Step S20: Based on the auxiliary power value, obtain the current position of the Stokes vector of the optical signal on the Poincaré sphere; It should be noted that the Stokes vector is used to fully describe the polarization state of partially or fully polarized light, and is composed of the total light intensity, the power difference between the horizontal (X) and vertical (Y) linear polarization components, and the +45° and... The vector consists of the power difference between the 45° linear polarization components and the power difference between the right-handed and left-handed circular polarization components. The Poincaré sphere is a three-dimensional geometric representation that maps all possible fully polarized states onto a unit sphere; the equator corresponds to the linear polarization state, the north and south poles correspond to the circular polarization state, and the remaining points correspond to the elliptically polarized state.

[0030] Understandably, by converting the auxiliary power value into a normalized power difference and combining it with the transmission power under a preset angle of beam splitting, the spatial position of the Stokes vector on the Poincaré sphere can be effectively reconstructed, thereby accurately describing the polarization state of the current optical signal. Furthermore, it avoids measuring all four Stokes parameters and completes polarization state positioning using only three power values, thus reducing hardware resource consumption and signal processing delay.

[0031] Step S30: Based on the current position, determine the polarization rotation angle required for the Stokes vector to rotate to a power balance between X-polarization and Y-polarization; It should be noted that X-polarization is the linearly polarized component of the electric field vector in an optical signal that vibrates along a predetermined horizontal direction (usually defined as the transverse X-axis in the fiber optic link coordinate system). Y-polarized optical signals have an electric field vector that vibrates along a direction orthogonal to X-polarization (i.e., a predetermined Y-axis, usually the vertical direction). Power balance means that the projected power on the two orthogonal polarization bases in the X and Y branches is equal. The polarization rotation angle is the angle required to rotate the current Stokes vector around the direction of light propagation to satisfy the power balance condition for X and Y polarization.

[0032] It is understandable that using the power balance between X-polarization and Y-polarization (i.e., the normalized power difference is zero) as the control objective can maximize the received signal-to-noise ratio of the optical signal polarization state and avoid signal crosstalk and sensitivity degradation caused by polarization imbalance.

[0033] Understandably, determining the polarization rotation angle within the Poincaré sphere geometry framework ensures the physical consistency and mathematical rigor of the control strategy, thereby improving the accuracy and convergence speed of polarization adjustment.

[0034] Understandably, based on the current position of the Stokes vector, the polarization rotation angle required to rotate the Stokes vector to achieve power balance between X and Y polarization can be directly determined, avoiding iteration and thus reducing control complexity and response delay.

[0035] Step S40: Adjust the polarization state of the optical signal based on the polarization rotation angle.

[0036] It should be noted that polarization state adjustment is based on the calculated polarization rotation angle, which drives the polarization control device to apply corresponding phase delay or rotation operations to the optical signal so that its output polarization state reaches the target state.

[0037] Understandably, by driving the electronically controlled polarization controller to adjust the optical signal in real time based on the calculated polarization rotation angle, it can actively suppress polarization drift caused by fiber bending, temperature changes or vibration, and maintain polarization stability at the receiving end.

[0038] Understandably, forming a closed-loop feedback mechanism for the adjustment process can enable data centers to quickly recover to their optimal operating point when faced with sudden polarization disturbances, thereby improving the robustness and availability of communication links.

[0039] In practical implementation, the power balance characteristics of the two orthogonal X and Y branches and the geometric relationship of the Stokes vector on the Poincaré sphere can be fully utilized to directly and analytically calculate the required polarization rotation angle, achieving random polarization impairment compensation without any iterative process. This not only reduces control complexity and response delay but also enables stable and efficient polarization alignment under arbitrary random polarization conditions. Furthermore, polarization state suppression methods in fiber optic links can be applied to the module, allowing it to be directly installed in the front end of a standard receiver. This achieves excellent engineering applicability and deployment compatibility without requiring any modifications to existing receiver hardware or signal processing procedures.

[0040] This embodiment provides a method for suppressing polarization states in an optical fiber link. At the zero-difference coherent optical communication receiver, the power of the received optical signal is detected to obtain an auxiliary power value. Based on this auxiliary power value, the current position of the Stokes vector of the optical signal on the Poincaré sphere is calculated in real time. Then, the polarization rotation angle required to rotate to the power balance state of X-polarization and Y-polarization is determined. Based on this, the polarization state of the optical signal is dynamically adjusted to make full use of the power balance characteristics of the two orthogonal branches of X and Y and the geometric relationship of the Stokes vector on the Poincaré sphere. The required polarization rotation angle is directly analyzed to achieve random polarization state damage compensation without any iterative process. This application indirectly characterizes polarization state changes by utilizing auxiliary power values. Without the need for additional high-complexity polarization tracking hardware or high-speed feedback loops, the receiver can quickly sense and compensate for polarization imbalances, ensuring that the optical signal always maintains a good polarization matching state. This improves coherent mixing efficiency and signal-to-noise ratio, avoiding demodulation distortion caused by random polarization evolution and reducing dependence on the polarization stability of the transmitter. Without increasing system power consumption and hardware complexity, it effectively suppresses the risk of bit errors caused by polarization state disturbances.

[0041] Based on the first embodiment of this application, in the second embodiment of this application, the content that is the same as or similar to that in Embodiment 1 above can be referred to the above description, and will not be repeated hereafter. Based on this, please refer to... Figure 2 Step S10 also includes steps S01 to S03: Step S01: The received optical signal is split to obtain a first split signal when the angle between the optical signal and the preset baseline is zero, and a second split signal when the angle is a preset angle. Step S02: Detect the transmitted light power of the first spectral signal to obtain the first transmitted light power, and detect the reflected light power to obtain the reflected light power. Step S03: Detect the transmitted light power of the second spectral signal to obtain the second transmitted light power.

[0042] It should be noted that the splitting process utilizes a passive optical splitter to distribute a single input optical signal to multiple output branches according to a preset ratio. The preset baseline is a reference polarization direction defined artificially in the receiving system, for example, corresponding to the transmission axis direction (i.e., the X-polarization direction) of the polarization beamsplitter. The first split signal is the optical signal input to a polarization beamsplitter with the preset baseline as its transmission axis after splitting. The second split signal is the optical signal input to another polarization beamsplitter after splitting, whose transmission axis is rotated by 45° (a preset angle) relative to the preset baseline, used to obtain power projection information in the ±45° linear polarization direction. Transmitted light power is the optical power output along the transmission axis direction after the incident light signal passes through the polarization beamsplitter. Reflected light power is the optical power output along the reflection axis direction after the incident light signal is reflected by the polarization beamsplitter.

[0043] Understandably, by splitting the optical signal and detecting the transmission / reflection power at 0° and a preset angle (such as 45°), sufficient information can be obtained to reconstruct the key components of the Stokes vector without using a full polarization analyzer, thereby reducing hardware costs.

[0044] It is understandable that, since the first transmitted light power and the reflected light power directly reflect the energy distribution of the X / Y orthogonal polarization channel, the difference between the two can be used to quickly determine whether the power balance condition is met; while the second transmitted light power provides polarization information in the ±45° direction, thus enabling the positioning of the Stokes vector on the Poincaré sphere to be extended from one dimension to two dimensions, thereby improving the accuracy of polarization state identification.

[0045] It is understandable that by accurately acquiring the first transmitted light power, the reflected light power, and the second transmitted light power, not only can the polarization rotation angle be resolved, but the polarization extinction ratio and polarization-related loss can also be estimated, thus realizing the integration of communication and monitoring functions.

[0046] Furthermore, step S03 also includes: Based on the first transmitted light power and the reflected light power, the X-polarization power in the X branch and the Y-polarization power in the Y branch of the optical signal after it is mapped to Stokes space are determined. The X-polarization power and the Y-polarization power are normalized to obtain the normalized power difference between the X branch and the Y branch; Based on the normalized power difference and the second transmitted light power, the current position of the Stokes vector of the optical signal on the Poincaré sphere is obtained.

[0047] It should be noted that Stokes space is a four-dimensional real vector space used to fully describe any polarization state. The X-branch is the signal path for processing the X-polarization component, with input from the transmission end of the polarization beamsplitter. The Y-branch is for processing the Y-polarization component, with input from the reflection end of the polarization beamsplitter. X-polarization power is the optical power component of the optical signal in the X-polarization direction. Y-polarization power is the optical power component of the optical signal in the Y-polarization direction. The normalized power difference is the ratio of the difference between the X-polarization power and the Y-polarization power to their sum, used to characterize the degree of X / Y polarization imbalance. The current position is used to characterize the polarization state type (linear / circular / elliptical) and orientation of the current optical signal.

[0048] It is understandable that by directly determining the X / Y polarization power based on the first transmitted light power and the reflected light power, complex polarization modulation or phase demodulation of the original light signal is avoided, so that the polarization state sensing process only depends on intensity detection.

[0049] It is understandable that by combining the normalized power difference with the second transmitted light power, the position of the Stokes vector on the equatorial plane of the Poincaré sphere (i.e., the linear polarization subspace) can be effectively reconstructed without measuring the power difference between the right-hand and left-hand circular polarization components. This meets the control requirements of optical fiber communication scenarios dominated by linear polarization, while taking into account both accuracy and efficiency, thereby suppressing the risk of bit errors caused by polarization state disturbances.

[0050] Further, the step of obtaining the current position of the Stokes vector of the optical signal on the Poincaré sphere based on the normalized power difference and the second transmitted light power includes: Based on the normalized power difference, the XY polarization components of the Stokes vector in the XY plane are determined, where the XY plane is the plane formed by the X branch and the Y branch; Based on the second transmitted light power, the preset angular polarization component of the second spectral signal corresponding to the Stokes vector is determined; Determine whether the sum of the squared frequencies of the XY polarization components and the preset angular polarization components is greater than a preset threshold; If the value is greater than the preset threshold, the XY polarization component and the preset angular polarization component are normalized to obtain the current position of the Stokes vector of the optical signal on the Poincaré sphere.

[0051] It should be noted that the XY plane is a two-dimensional plane in the Poincaré spherical coordinate system, spanned by the XY linear polarization components and ±45° linear polarization components of the Stokes parameter, corresponding to the set of all linear polarization states. The XY polarization components are the projection components of the Stokes vector onto the XY plane. The preset angular polarization component is the projection intensity of the optical signal in the 45° (preset angle) polarization direction. The preset threshold is used to determine whether the current optical signal has sufficient linear polarization characteristics to support effective polarization rotation control; for example, 1. Since the Stokes vector must be less than or equal to 1, the preset threshold can be 1.

[0052] Understandably, by using the judgment mechanism of sum of squares and preset thresholds, low polarization or depolarized light signals can be effectively identified, preventing the control system from continuously adjusting in a meaningless state, thereby improving system stability and energy efficiency.

[0053] It is understandable that the Stokes vector will be distorted due to the weak circular polarization component, which will lead to a deviation in the final determined polarization rotation angle. Therefore, a preset threshold can be used for automatic detection and correction to maintain the high accuracy of the Stokes vector.

[0054] It is understandable that by splitting the received optical signal and detecting the power of multiple transmitted and reflected optical signals, a low-cost photodetector can replace a complex polarization analyzer, thereby obtaining key information for characterizing the polarization state. It is also understandable that this auxiliary power value does not depend on directly measuring the polarization direction, but rather indirectly reflects the polarization characteristics through power projection under orthogonal bases (such as 0° and 45°), thus enabling polarization state sensing without increasing system complexity. Furthermore, it is understandable that using a beam splitter in conjunction with a standard polarization beam splitter for power detection makes the entire detection module easy to integrate into a miniaturized optical transceiver module, which is beneficial for large-scale deployment in high-speed coherent communication systems.

[0055] Based on the first and second embodiments of this application, the same or similar content as the above embodiments in the third embodiment of this application can be referred to the above description, and will not be repeated hereafter. Based on this, please refer to... Figure 3 Step S30 also includes steps S1 to S3: Step S1: Based on the current position, determine whether the normalized power difference of the optical signal is zero; Step S2: If the normalized power difference is zero, then the polarization rotation angle required for the Stokes vector to rotate to the power balance between X polarization and Y polarization is determined to be zero. Step S3: If the normalized power difference is not zero, then the normalized power difference being zero is taken as the stopping condition for the rotation of the Stokes vector, and the required polarization rotation angle of the Stokes vector is determined.

[0056] It should be noted that the stopping condition is the criterion for determining the completion of the polarization adjustment process.

[0057] Understandably, explicitly setting the normalized power difference to zero as the rotation stop condition makes the control target clear and quantifiable, ensuring that polarization adjustment always moves in the direction of improving the performance of the polarization multiplexing system, avoiding blind adjustment, and achieving precise positioning in a single operation.

[0058] Understandably, transforming the polarization control problem into a geometric rotation problem has a rigorous physical basis within the Poincaré sphere framework, thus ensuring the universality and predictability of the control strategy, unaffected by the wavelength of the light source or the modulation format.

[0059] Furthermore, step S3 also includes: The polarization angle of the optical signal is determined by using the normalized power difference to be zero as the stopping condition for the Stokes vector rotation. Based on the auxiliary power value, the first optical power value of the first split signal after the optical signal is split at zero degrees is determined, and the second optical power value of the second split signal after the optical signal is split according to a preset angle is determined. The polarization direction of the optical signal is determined by comparing the first optical power value with the second optical power value and based on the magnitude of the comparison. Based on the polarization direction, the required polarization rotation angle for the Stokes vector is determined from the polarization angle.

[0060] It should be noted that the polarization angle is the angle between the linear polarization direction of the optical signal and the preset baseline (X branch). The orientation of the principal axis of the electric field vibration of linearly polarized light in the XY plane can be determined by the relative magnitude of the first optical power value and the second optical power value, indicating whether it is located in the 0°–90° or 90°–180° range.

[0061] It is understandable that by comparing the magnitudes of the first optical power value (0°) and the second optical power value (45°) to determine the quadrant of the polarization direction, the ambiguity of the polarization angle can be resolved without adding extra hardware, thereby improving the accuracy of angle determination.

[0062] Further, the step of determining the polarization angle of the optical signal by using the normalized power difference to be zero as the stopping condition for the Stokes vector rotation includes: The normalized power difference being zero is used as the stopping condition for the Stokes vector rotation, and the initial polarization angle of the optical signal is determined. Based on the normalized power difference, determine the amount of change in normalized power difference caused by the change in unit polarization rotation angle; Based on the change, the initial polarization angle is corrected to obtain the polarization rotation angle.

[0063] It should be noted that the initial polarization angle is a preliminary estimate of the optical signal polarization direction based on the current Stokes vector position. This angle does not account for system nonlinearity or device errors and may contain inaccuracies. The change is the change in normalized power difference after applying a unit polarization rotation angle.

[0064] Understandably, by using differential feedback to correct the initial polarization angle, an upgrade from open-loop analytical estimation to closed-loop adaptive correction is achieved, which can still approximate the target state with high accuracy even when the device parameters are not precisely known.

[0065] It is understandable that, due to the potential for nonlinear response in polarization controllers, quantization noise in optical power detection, model errors in Stokes vector reconstruction, and the fact that the polarization rotation angle is an ideal angle that may deviate from the actual situation, after determining the initial polarization angle of the optical signal, the change in normalized power difference caused by a unit change in polarization rotation angle is determined based on the normalized power difference. This change is then used to correct the initial polarization angle, which can reduce the influence of external factors on the adjustment of optical information and thus improve the accuracy of polarization angle adjustment of optical information.

[0066] It should be noted that the above examples are only for understanding this application and do not constitute a limitation on the method of suppressing polarization state in the optical fiber link of this application. Any simple transformations based on this technical concept are within the protection scope of this application.

[0067] This application also provides a polarization state suppression device in an optical fiber link, please refer to... Figure 4 The polarization state suppression device in the optical fiber link includes: The detection module 10 is used to perform power detection on the received optical signal and obtain an auxiliary power value; Position analysis module 20 is used to obtain the current position of the Stokes vector of the optical signal on the Poincaré sphere based on the auxiliary power value; The determining module 30 is used to determine, based on the current position, the polarization rotation angle required for the Stokes vector to rotate to a power balance between X-polarization and Y-polarization; The adjustment module 40 is used to adjust the polarization state of the optical signal based on the polarization rotation angle.

[0068] Optionally, the auxiliary power value includes a first transmitted light power, a reflected light power, and a second transmitted light power; The detection module 10 is further configured to perform splitting processing on the received optical signal to obtain a first split signal when the angle between the optical signal and the preset baseline is zero, and a second split signal when the angle is a preset angle; to perform transmitted light power detection on the first split signal to obtain a first transmitted light power, and to perform reflected light power detection to obtain reflected light power; and to perform transmitted light power detection on the second split signal to obtain a second transmitted light power.

[0069] Optionally, the detection module 10 is further configured to determine, based on the first transmitted light power and the reflected light power, the X-polarization power of the optical signal mapped to Stokes space in the X branch and the Y-polarization power in the Y branch; normalize the X-polarization power and the Y-polarization power to obtain the normalized power difference between the X branch and the Y branch; and obtain the current position of the Stokes vector of the optical signal on the Poincaré sphere based on the normalized power difference and the second transmitted light power.

[0070] Optionally, the detection module 10 is further configured to: determine the XY polarization component of the Stokes vector in the XY plane based on the normalized power difference, wherein the XY plane is the plane formed by the X branch and the Y branch; determine the preset angular polarization component of the second beam splitting signal corresponding to the Stokes vector based on the second transmitted light power; determine whether the sum of the squares of the XY polarization component and the preset angular polarization component is greater than a preset threshold; if it is greater than the preset threshold, normalize the XY polarization component and the preset angular polarization component to obtain the current position of the Stokes vector of the optical signal on the Poincaré sphere.

[0071] Optionally, the determining module 30 is further configured to determine, based on the current position, whether the normalized power difference of the optical signal is zero; if the normalized power difference is zero, then determine that the polarization rotation angle required for the Stokes vector to rotate to the power balance between X-polarization and Y-polarization is zero; if the normalized power difference is not zero, then use the normalized power difference being zero as the stopping condition for the rotation of the Stokes vector, and determine the polarization rotation angle required for the Stokes vector.

[0072] Optionally, the determining module 30 is further configured to use the normalized power difference being zero as the stopping condition for the Stokes vector rotation, determine the polarization angle of the optical signal; based on the auxiliary power value, determine the first optical power value of the first split signal after the optical signal is split at zero degrees, and determine the second optical power value of the second split signal after the optical signal is processed according to a preset angle; compare the magnitude of the first optical power value and the second optical power value, and determine the polarization direction of the optical signal based on the magnitude; and based on the polarization direction, determine the required polarization rotation angle of the Stokes vector from the polarization angle.

[0073] Optionally, the determining module 30 is further configured to use the normalized power difference being zero as the stopping condition for the Stokes vector rotation, determine the initial polarization angle of the optical signal; determine the change in normalized power difference caused by a unit change in polarization rotation angle based on the normalized power difference; and correct the initial polarization angle based on the change to obtain the polarization rotation angle.

[0074] The polarization state suppression device in the optical fiber link provided in this application employs the polarization state suppression method in the optical fiber link described in the above embodiments. This addresses the technical problem that random polarization states occur in the local oscillator light in optical interconnect optical fiber lines, and that changes in these random polarization states can affect data center performance, thereby causing a higher bit error rate. Compared with the prior art, the beneficial effects of the polarization state suppression device in the optical fiber link provided in this application are the same as those of the polarization state suppression method in the optical fiber link provided in the above embodiments. Furthermore, other technical features of the polarization state suppression device in the optical fiber link are the same as those disclosed in the methods of the above embodiments, and will not be repeated here.

[0075] This application provides a device for suppressing polarization states in an optical fiber link. The device includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, which are executed by the at least one processor to enable the at least one processor to perform the method for suppressing polarization states in an optical fiber link as described in Embodiment 1 above.

[0076] The following is for reference. Figure 5 This document illustrates a structural schematic diagram of a device suitable for implementing polarization state suppression in an optical fiber link according to embodiments of this application. The device for suppressing polarization state in an optical fiber link in embodiments of this application may include, but is not limited to, mobile terminals such as mobile phones, laptops, digital broadcast receivers, PDAs (Personal Digital Assistants), PADs (Portable Application Description), PMPs (Portable Media Players), in-vehicle terminals (e.g., in-vehicle navigation terminals), and fixed terminals such as digital TVs and desktop computers. Figure 5 The polarization state suppression device shown in the optical fiber link is merely an example and should not impose any limitation on the functionality and scope of use of the embodiments of this application.

[0077] like Figure 5As shown, the polarization suppression device in the optical fiber link may include a processing unit 1001 (e.g., a central processing unit, a graphics processing unit, etc.), which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 1002 or a program loaded from a storage device 1003 into a random access memory (RAM) 1004. The RAM 1004 also stores various programs and data required for the operation of the polarization suppression device in the optical fiber link. The processing unit 1001, ROM 1002, and RAM 1004 are interconnected via a bus 1005. An input / output (I / O) interface 1006 is also connected to the bus. Typically, the following systems can be connected to I / O interface 1006: input devices 1007 including, for example, touchscreens, touchpads, keyboards, mice, image sensors, microphones, accelerometers, gyroscopes, etc.; output devices 1008 including, for example, liquid crystal displays (LCDs), speakers, vibrators, etc.; storage devices 1003 including, for example, magnetic tapes, hard disks, etc.; and communication devices 1009. Communication device 1009 allows the polarization suppression device in the fiber optic link to exchange data wirelessly or via wired communication with other devices. Although various systems of polarization suppression devices in fiber optic links are shown in the figure, it should be understood that it is not required to implement or possess all of the systems shown. More or fewer systems may be implemented alternatively.

[0078] Specifically, according to the embodiments disclosed in this application, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments disclosed in this application include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication device, or installed from storage device 1003, or installed from ROM 1002. When the computer program is executed by processing device 1001, it performs the functions defined in the methods of the embodiments disclosed in this application.

[0079] The polarization state suppression device in the optical fiber link provided in this application employs the polarization state suppression method in the optical fiber link described in the above embodiments. This addresses the technical problem that random polarization states occur in the local oscillator light in optical interconnect optical fiber lines, and that changes in these random polarization states can affect data center performance, thereby causing a higher bit error rate. Compared with the prior art, the beneficial effects of the polarization state suppression device in the optical fiber link provided in this application are the same as those of the polarization state suppression method in the optical fiber link provided in the above embodiments. Furthermore, other technical features of this polarization state suppression device are the same as those disclosed in the previous embodiment method, and will not be repeated here.

[0080] It should be understood that the various parts disclosed in this application can be implemented using hardware, software, firmware, or a combination thereof. In the description of the above embodiments, specific features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0081] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0082] This application provides a computer-readable storage medium having computer-readable program instructions (i.e., a computer program) stored thereon, the computer-readable program instructions being used to execute the method for suppressing polarization states in an optical fiber link as described in the above embodiments.

[0083] The computer-readable storage medium provided in this application may be, for example, a USB flash drive, but is not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or any combination thereof. More specific examples of computer-readable storage media may include, but are not limited to: electrical connections having one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this embodiment, the computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, system, or device. The program code contained on the computer-readable storage medium may be transmitted using any suitable medium, including but not limited to: wires, optical cables, RF (Radio Frequency), etc., or any suitable combination thereof.

[0084] The aforementioned computer-readable storage medium may be included in a polarization state suppression device in an optical fiber link; or it may exist independently and not be assembled into a polarization state suppression device in an optical fiber link.

[0085] The aforementioned computer-readable storage medium carries one or more programs, which, when executed by a polarization state suppression device in an optical fiber link, cause the polarization state suppression device in the optical fiber link to implement the aforementioned polarization state suppression method in the optical fiber link.

[0086] Computer program code for performing the operations of this application can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, and C++, and conventional procedural programming languages ​​such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a Local Area Network (LAN) or a Wide Area Network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0087] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0088] The modules described in the embodiments of this application can be implemented in software or hardware. The names of the modules do not necessarily limit the functionality of the unit itself.

[0089] The readable storage medium provided in this application is a computer-readable storage medium that stores computer-readable program instructions (i.e., a computer program) for executing the above-described method for suppressing polarization states in optical fiber links. This solves the technical problem that random polarization states occur in the local oscillator light in optical interconnected optical fiber lines, and that changes in these random polarization states affect the performance of data centers, thereby causing high bit error rates. Compared with the prior art, the beneficial effects of the computer-readable storage medium provided in this application are the same as those of the polarization state suppression method in optical fiber links provided in the above embodiments, and will not be repeated here.

[0090] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the above-described method for suppressing polarization states in an optical fiber link.

[0091] The computer program product provided in this application can solve the technical problem that the local oscillator light in optical interconnect fiber optic lines exhibits random polarization states, and that changes in these random polarization states can affect the performance of data centers, thereby causing high bit error rates. Compared with the prior art, the beneficial effects of the computer program product provided in this application are the same as those of the polarization state suppression method in the optical fiber link provided in the above embodiments, and will not be repeated here.

[0092] The above description is only a part of the embodiments of this application and does not limit the scope of protection of this application. All equivalent structural transformations made under the technical concept of this application and using the content of this application specification and drawings, or direct / indirect applications in other related technical fields, are included in the scope of protection of this application.

Claims

1. A method for suppressing polarization states in an optical fiber link, characterized in that, The method includes: The received optical signal is subjected to power detection to obtain an auxiliary power value, which includes a first transmitted light power, a reflected light power, and a second transmitted light power obtained by splitting and detecting based on different angles between the optical signal and a preset baseline. Based on the auxiliary power value, the current position of the Stokes vector of the optical signal on the Poincaré sphere is obtained; Based on the current position, the polarization rotation angle required for the Stokes vector to rotate to power balance between X-polarization and Y-polarization is determined in one step through geometric analysis. The polarization state of the optical signal is adjusted based on the polarization rotation angle.

2. The method as described in claim 1, characterized in that, The auxiliary power value includes a first transmitted light power, a reflected light power, and a second transmitted light power; The step of performing power detection on the received optical signal to obtain an auxiliary power value includes: The received optical signal is split to obtain a first split signal when the angle between the optical signal and the preset baseline is zero, and a second split signal when the angle is a preset angle. The first transmitted light power is obtained by detecting the transmitted light power of the first spectral signal, and the reflected light power is obtained by detecting the reflected light power. The transmitted light power of the second spectral signal is detected to obtain the second transmitted light power.

3. The method as described in claim 2, characterized in that, The step of obtaining the current position of the Stokes vector of the optical signal on the Poincaré sphere based on the auxiliary power value includes: Based on the first transmitted light power and the reflected light power, the X-polarization power in the X branch and the Y-polarization power in the Y branch of the optical signal after it is mapped to Stokes space are determined. The X-polarization power and the Y-polarization power are normalized to obtain the normalized power difference between the X branch and the Y branch; Based on the normalized power difference and the second transmitted light power, the current position of the Stokes vector of the optical signal on the Poincaré sphere is obtained.

4. The method as described in claim 3, characterized in that, The step of obtaining the current position of the Stokes vector of the optical signal on the Poincaré sphere based on the normalized power difference and the second transmitted light power includes: Based on the normalized power difference, the XY polarization components of the Stokes vector in the XY plane are determined, where the XY plane is the plane formed by the X branch and the Y branch; Based on the second transmitted light power, the preset angular polarization component of the second spectral signal corresponding to the Stokes vector is determined; Determine whether the sum of the squared frequencies of the XY polarization components and the preset angular polarization components is greater than a preset threshold; If the value is greater than the preset threshold, the XY polarization component and the preset angular polarization component are normalized to obtain the current position of the Stokes vector of the optical signal on the Poincaré sphere.

5. The method as described in claim 1, characterized in that, The step of determining the polarization rotation angle required for the Stokes vector to rotate to power balance between X-polarization and Y-polarization based on the current position includes: Based on the current position, determine whether the normalized power difference of the optical signal is zero; If the normalized power difference is zero, then the polarization rotation angle required for the Stokes vector to rotate to power balance between X-polarization and Y-polarization is determined to be zero. If the normalized power difference is not zero, then the normalized power difference being zero is used as the stopping condition for the rotation of the Stokes vector, and the required polarization rotation angle of the Stokes vector is determined.

6. The method as described in claim 5, characterized in that, The step of determining the required polarization rotation angle of the Stokes vector by using the normalized power difference to be zero as the stopping condition for the rotation of the Stokes vector includes: The polarization angle of the optical signal is determined by using the normalized power difference to be zero as the stopping condition for the Stokes vector rotation. Based on the auxiliary power value, the first optical power value of the first split signal after the optical signal is split at zero degrees is determined, and the second optical power value of the second split signal after the optical signal is split according to a preset angle is determined. The polarization direction of the optical signal is determined by comparing the first optical power value with the second optical power value and based on the magnitude of the comparison. Based on the polarization direction, the required polarization rotation angle for the Stokes vector is determined from the polarization angle.

7. The method as described in claim 6, characterized in that, The step of determining the polarization angle of the optical signal by using the normalized power difference to be zero as the stopping condition for the Stokes vector rotation includes: The normalized power difference being zero is used as the stopping condition for the Stokes vector rotation, and the initial polarization angle of the optical signal is determined. Based on the normalized power difference, determine the amount of change in normalized power difference caused by the change in unit polarization rotation angle; Based on the change, the initial polarization angle is corrected to obtain the polarization rotation angle.

8. A polarization state suppression device in an optical fiber link, characterized in that, The device includes: The detection module is used to perform power detection on the received optical signal and obtain an auxiliary power value. The auxiliary power value includes a first transmitted light power, a reflected light power, and a second transmitted light power obtained by splitting and detecting based on different angles between the optical signal and a preset baseline. The position analysis module is used to obtain the current position of the Stokes vector of the optical signal on the Poincaré sphere based on the auxiliary power value; The determination module is used to determine, based on the current position, the polarization rotation angle required for the Stokes vector to be rotated to power balance between X-polarization and Y-polarization in one step through geometric analysis; The adjustment module is used to adjust the polarization state of the optical signal based on the polarization rotation angle.

9. A polarization state suppression device in an optical fiber link, characterized in that, The device includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, the computer program being configured to implement the steps of the method for suppressing polarization states in an optical fiber link as claimed in any one of claims 1 to 7.

10. A storage medium, characterized in that, The storage medium is a computer-readable storage medium, and a computer program is stored on the storage medium. When the computer program is executed by a processor, it implements the steps of the method for suppressing polarization states in an optical fiber link as described in any one of claims 1 to 7.

Images