Ferroelectric liquid crystal based column vector beam dynamic multiplexing demultiplexing system and method of using the same

Abstract

The application provides a column vector light beam dynamic multiplexing and demultiplexing system based on ferroelectric liquid crystal and a use method thereof. The system comprises a transmitting end, a transmission section, a receiving end and an electric control driving control unit. The transmitting end generates and switches column vector light beam topology through multi-path light source modulation, polarization setting and ferroelectric liquid crystal Q wave plate, and coaxially superimposes the column vector light beam topology into a multiplexed light beam through a beam combiner. The transmission section carries the light beam propagation. The receiving end realizes selective demultiplexing through the cascade reverse transformation of the ferroelectric liquid crystal Q wave plate and the liquid crystal variable delay device, and completes signal detection after polarization separation and single-mode coupling. The electric control unit synchronously controls the state switching and channel addressing of each module. The system has significantly improved switching speed and better stability, can work at a lower driving voltage, can adjust the available channel set and mapping relationship as needed, is more suitable for resource scheduling requirements of burst traffic in a data center, can be directly connected to a commercial receiver, and is conducive to large-scale deployment.

Description

Technical Field

[0001] This application relates to the field of mode multiplexing technology, and in particular to a dynamic multiplexing and demultiplexing system for cylindrical vector beams based on ferroelectric liquid crystals and its usage method. Background Technology

[0002] As artificial intelligence computing enters a high-throughput phase characterized by large-scale model training, GPU / accelerator card clusters require large-scale parameter synchronization and cross-node data exchange. Training services exhibit characteristics such as high burstiness, high concurrency, and significant dynamic changes in traffic. This necessitates that data center interconnect networks not only provide higher link bandwidth but also possess dynamic channel allocation and efficient routing capabilities to avoid increased latency and decreased computing power utilization due to bandwidth bottlenecks in parameter synchronization and gradient convergence. To break through the capacity limits of traditional single-mode fiber and further explore the potential of spatial multiplexing, Mode Division Multiplexing (MDM) is considered an important technical route for improving interconnect capacity. Its basic idea is to transmit multiple mutually orthogonal spatial mode channels in parallel on the same physical link, thereby increasing the overall transmission capacity without consuming additional spectrum resources. However, existing MDM systems still generally face the problem of static channel configuration when deployed in data center scenarios: once the mode mapping relationship of multiplexing / demultiplexing devices is fixed in the design or manufacturing stage, the system cannot make real-time adjustments according to service load, topology changes, or congestion status, and thus cannot adapt to the dynamic traffic patterns within the data center. This results in cross-node synchronization often being limited by insufficient bandwidth, leading to problems such as increased communication latency and dragging down overall training efficiency. Therefore, the current demand for optical interconnects in data centers is no longer limited to simply increasing bandwidth, but emphasizes the reconfigurability of the interconnect network, including flexible reconfiguration of network topology, on-demand resource scheduling, interconnect congestion mitigation, and resource utilization optimization, so that "capacity advantage" and "switching / switching flexibility" can be taken into account at the same time. Building a low-latency, high-efficiency, and programmable optical interconnect architecture is gradually becoming an important development direction for the next generation of intelligent computing infrastructure.

[0003] In recent years, key device technologies such as photonic lanterns and multi-plane light conversion (MPLC) have matured and been widely adopted in the engineering implementation of mode multiplexing. Photonic lanterns achieve mode mapping between multiple single-mode and few-mode / multi-mode modes through a gradient structure, offering advantages such as compact structure, low insertion loss, and easy compatibility with fiber optic systems. MPLCs achieve precise mode conversion and separation by modulating the wavefront stepwise through multiple phase plates, typically possessing high mode purity and a certain degree of mode selection flexibility. These technologies have, to some extent, solved the fundamental problems of mode multiplexing / demultiplexing, promoting the practical application of MDM systems. However, the above mainstream solutions are generally static device systems, and their mode conversion relationships and channel mappings are basically fixed after manufacturing, making it difficult to achieve high-speed reconfigurable switching during system operation. This limits their application potential in data center interconnects that require dynamic scheduling and real-time reconfiguration. The main shortcomings of existing technologies are as follows: 1. Fixed multiplexing / demultiplexing relationship: The mode mapping of devices such as photonic lanterns and MPLCs is fixed after manufacturing, making it impossible to dynamically switch and reallocate resources from any channel to any end as business changes occur; 2. Insufficient response speed: Traditional liquid crystal (especially nematic liquid crystal) devices mostly have millisecond-level responses; mechanical rotation / replacement of optical components is even slower, which cannot match the microsecond-level or even faster switching requirements of data center interconnects; 3. Poor scalability and device stacking lead to system complexity: In order to cover more modes / more orders / more polarization states, existing systems often need to add a large number of static devices or complex optical paths, resulting in increased insertion loss, alignment difficulty and cost; 4. Insufficient selective demultiplexing capability: Some CVB communication systems can only demultiplex fixed orders or fixed polarization states, making it difficult to achieve selective demultiplexing of CVBs of any order and zero-order output that is easy to couple with single-mode fiber. Summary of the Invention

[0004] This application provides a dynamic multiplexing and demultiplexing system for cylindrical vector beams based on ferroelectric liquid crystals and its usage method, aiming to solve at least one of the technical problems mentioned above, such as fixed multiplexing / demultiplexing relationship, insufficient response speed, poor scalability, system complexity caused by device stacking, and insufficient selective demultiplexing capability.

[0005] To achieve the above objectives, the first aspect of this application provides a dynamic multiplexing and demultiplexing system for cylindrical vector beams based on ferroelectric liquid crystals. The dynamic multiplexing and demultiplexing system for cylindrical vector beams based on ferroelectric liquid crystals includes a transmitter, a transmission segment, a receiver, and an electronically controlled drive control unit. The transmitter, the transmission segment, the receiver, and the electronically controlled drive control unit work together to complete the electronic reconstruction of multi-channel parallel communication and arbitrary channel switching.

[0006] The transmitter is used to convert multiple Gaussian light signals carrying data into cylindrical vector beams of different orders and polarization topologies, and coaxially combine them into a multiplexed beam. The transmitter includes a multi-source light source and modulation module, a polarization setting module, a cylindrical vector beam generation and dynamic switching module, and a coaxial multiplexing and combining module. The multi-source light source and modulation module outputs multi-path polarized Gaussian light and loads data signals. The polarization setting module provides stable orthogonal linear polarization input for each path-polarized Gaussian light, serving as a reference for cylindrical vector beam generation and sub-state definition. The cylindrical vector beam generation... The dynamic switching module includes multiple ferroelectric liquid crystal Q-wave plates. The cylindrical vector beam generation and dynamic switching module is used to convert linearly polarized Gaussian light with polarization set into a cylindrical vector beam of a specified order, and outputs the radial or angular polarization topology of the cylindrical vector beam through electronically controlled dynamic switching. The electronically controlled drive control unit is electrically connected to the cylindrical vector beam generation and dynamic switching module to realize electronically controlled switching control. The coaxial multiplexing and beam combining module includes several beam splitters and / or beam combiners. The coaxial multiplexing and beam combining module is used to coaxially superimpose multiple cylindrical vector beams and send them into the transmission section.

[0007] The transmission segment is used to carry the stable propagation of the multiplexed beam;

[0008] The receiving end is used for dynamic selective demultiplexing, polarization separation, and coupling reception of the multiplexed beam. The receiving end includes a dynamic demultiplexing module, a polarization separation module, and a single-mode coupling and receiving module. The dynamic demultiplexing module includes a ferroelectric liquid crystal Q-wave plate and a liquid crystal variable delayer arranged in a specific cascade relationship. One end of the dynamic demultiplexing module is connected to the transmission section, and the other end is connected to the polarization separation module. The dynamic demultiplexing module is used to perform selective inverse transformation on the target order cylindrical vector beam channel, outputting a zero-order beam when matched and maintaining a higher-order or non-zero-order beam when mismatched. The electronically controlled drive control unit is electrically connected to the dynamic demultiplexing module to achieve state switching and target channel addressing. The polarization separation module includes a polarization beam splitter, used to separate orthogonal polarization components corresponding to radial and angular polarization and output them to different ports. The single-mode coupling and receiving module is correspondingly connected to each end of the polarization separation module, used to couple the target beam to a single-mode fiber coupler and send it to an optical receiver to complete the index measurement.

[0009] Optionally, the linear polarization input directions provided by the polarization setting module are mutually orthogonal.

[0010] Optionally, the transmission segment is a short-range free-space link; and / or, the transmission segment is a space-fiber hybrid short-range link.

[0011] Optionally, the number of ferroelectric liquid crystal Q-waveplates in the cylindrical vector beam generation and dynamic switching module is the same as the number of linearly polarized Gaussian optical paths output by the multi-source light source and modulation module.

[0012] Optionally, the cascade relationship between the ferroelectric liquid crystal Q-wave plate and the liquid crystal variable delay unit in the dynamic demultiplexing module matches the polarization topology switching logic of the cylindrical vector beam generation and dynamic switching module.

[0013] Optionally, the beam splitter is a polarization-dependent beam splitter, and the beam combiner is a polarization-independent beam combiner.

[0014] Optionally, the single-mode coupling and receiving module includes the single-mode fiber coupler and the optical receiver.

[0015] Optionally, the electronically controlled drive control unit outputs an electrical signal to synchronously control the polarization topology switching of the cylindrical vector beam generation and dynamic switching module and the target channel addressing of the dynamic demultiplexing module.

[0016] The second aspect of this application proposes a method for using a dynamic multiplexing and demultiplexing system for cylindrical vector beams based on ferroelectric liquid crystals, the method comprising the steps of: dynamic multiplexing at the transmitting end and dynamic demultiplexing at the receiving end;

[0017] The dynamic multiplexing of the transmitter includes the following steps:

[0018] The system generates and modulates multiple optical signals, generating N optical carriers through the multiple light sources and modulation modules, and loading digital modulation signals onto each optical carrier to output a multi-path polarized Gaussian beam.

[0019] The input polarization setting, through the polarization control or polarization holding device in the polarization setting module, sets each linearly polarized Gaussian beam to a predetermined linear polarization direction, which serves as the input condition for the generation of cylindrical vector beams and radial / angular nipple states;

[0020] The cylindrical vector beam generation and topology dynamic switching module converts each path-polarized Gaussian beam into a target-order cylindrical vector beam by passing through a ferroelectric liquid crystal Q-waveplate of the corresponding order in the module. The electronically controlled drive control unit applies bipolar drive to the ferroelectric liquid crystal Q-waveplate and switches the bipolar drive voltage polarity to achieve rapid switching between radial and angular polarization of the cylindrical vector beam, forming a dynamically selectable channel with two sub-states of the same order.

[0021] Coaxial beam combining and multiplexing involves coaxially superimposing multiple cylindrical vector beams through beam splitters and / or beam combiners in the coaxial multiplexing and multiplexing module to form a multiplexed beam, which is then output to the transmission segment.

[0022] The dynamic demultiplexing at the receiving end includes the following steps:

[0023] Multiplexed beam input: Receives the coaxial multiplexed cylindrical vector beam transmitted by the transmission segment and inputs it into the dynamic demultiplexing module;

[0024] In the demultiplexing state setting, the electronically controlled drive control unit controls the liquid crystal variable delay device in the dynamic demultiplexing module to be in an equivalent half-wave or equivalent full-wave state according to the order and polarization state of the target column vector beam, thereby constructing the matching inverse transformation conditions of the target channel.

[0025] The Q-plate cascaded inverse transformation and selective cancellation are performed, and the multiplexed beam passes through the cascaded component of the dynamic demultiplexing module, which consists of a ferroelectric liquid crystal Q-waveplate and a liquid crystal variable delayer. When the target channel meets the order matching / cancellation condition, the target cylindrical vector beam is selectively converted into a zero-order Gaussian-like, spatially polarized uniform beam and output. Non-target channels, because they do not meet the matching condition, maintain a high-order or non-zero-order output and are suppressed in the subsequent single-mode coupling process, thus achieving selective demultiplexing.

[0026] Polarization separation involves inputting the beam after cascaded inverse transformation into the polarization separation module, where a beam splitter separates the orthogonal polarization components corresponding to the radial and angular polarizations of the cylindrical vector beam, and outputs the two types of polarization components to different ports.

[0027] The single-mode coupling and receiving module couples the zero-order beams output from each port of the polarization separation module into the single-mode fiber coupler and sends them to the optical receiver for detection, thus completing the measurement of power, crosstalk, and bit error rate. Attached Figure Description

[0028] The accompanying drawings exemplify embodiments and form part of the specification, working together with the textual description to explain exemplary implementations of the embodiments. The drawings shown are for illustrative purposes only and do not limit the scope of the claims. Throughout the drawings, the same reference numerals refer to similar but not necessarily identical elements.

[0029] Figure 1 This is a schematic diagram of an embodiment of the dynamic multiplexing and demultiplexing system for cylindrical vector beams based on ferroelectric liquid crystals according to this application;

[0030] Figure 2 A schematic diagram illustrating the principle of generating a cylindrical vector beam for a Q-plate and controlling its polarization state;

[0031] Figure 3a Schematic diagram of the electrically controlled phase delay principle of a liquid crystal variable delay device Figure 1 ; Figure 3b Schematic diagram of the electrically controlled phase delay principle of a liquid crystal variable delay device Figure 2 ;

[0032] Figure 4 This is a flowchart illustrating the usage method of the ferroelectric liquid crystal-based cylindrical vector beam dynamic multiplexing and demultiplexing system of this application.

[0033] Detailed Implementation

[0034] To make the inventive objectives, features, and advantages of this application more apparent and understandable, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0035] Please see Figure 1 This application provides a dynamic multiplexing and demultiplexing system 100 for cylindrical vector beams based on ferroelectric liquid crystals. System 100 includes a transmitter, a transmission segment, a receiver, and an electronically controlled drive control unit. The transmitter, transmission segment, receiver, and electronically controlled drive control unit work together to achieve electronic reconstruction of multi-channel parallel communication and arbitrary channel switching. Electronic reconstruction is achieved by synchronously controlling the polarization topology switching at the transmitter and the channel addressing at the receiver through the output electrical signal of the electronically controlled drive control unit.

[0036] The transmitter converts multiple Gaussian optical signals carrying data into cylindrical vector beams of different orders and polarization topologies, and coaxially combines them into a multiplexed beam. Specifically, the different orders are integer or half-integer orders, and each order of cylindrical vector beam corresponds to a ferroelectric liquid crystal Q-plate (FLC Q-plate), with the order matching the phase delay of the ferroelectric liquid crystal Q-plate (detailed later). The transmitter adopts a modular architecture design, including a multi-source light source and modulation module, a polarization setting module, a cylindrical vector beam generation and dynamic switching module, and a coaxial multiplexing and combining module. These modules are connected sequentially via optical paths, and the electronically controlled drive control unit is electrically connected to the cylindrical vector beam generation and dynamic switching module, forming an integrated design of "optical path coordination + electronic control".

[0037] The transmitting end includes a multi-source light source and modulation module, which outputs multi-path polarized Gaussian light and loads data signals. As the optical signal source of the transmitting end, the multi-source light source and modulation module employs a multi-path independent light source array design. Each light source can be a high-stability, narrow-linewidth semiconductor laser, ensuring that no additional interference due to wavelength differences occurs during subsequent beam combining. Simultaneously, each light source can be configured with an independent electro-optic modulator to load the electrical domain data signal to be transmitted onto the corresponding linearly polarized Gaussian light signal, achieving the conversion from electrical to optical signals. During the loading process, the polarization state stability of the optical signal is strictly guaranteed, avoiding polarization distortion introduced during data loading, and providing a high-quality original optical signal for subsequent polarization setting and cylindrical vector beam conversion. The multi-source light source and modulation module can also integrate an optical power adjustment unit, which can independently adjust the power of each output optical signal according to subsequent transmission requirements, ensuring that the power of each corresponding cylindrical vector beam is balanced after beam combining, avoiding increased data transmission error rate due to power differences, and improving the stability of system transmission.

[0038] The transmitting end includes a polarization setting module, which provides stable orthogonal linear polarization input for each line-polarized Gaussian beam, serving as a reference for cylinder vector beam generation and sub-state definition. The polarization setting module is connected to the output of the multi-source light source and modulation module, and is used to calibrate the polarization state and set the reference for each line-polarized Gaussian beam with loaded data. This is a crucial prerequisite for subsequently generating a stable cylinder vector beam. The polarization setting module can be designed using a combination of a high-precision polarization controller and an orthogonal polarization generator. Each polarization control unit of the polarization setting module operates independently, allowing for personalized calibration based on the polarization characteristics of optical signals from different optical paths, avoiding polarization interference between multiple optical signals.

[0039] The transmitting end includes a cylindrical vector beam generation and dynamic switching module, which comprises multiple ferroelectric liquid crystal Q-wave plates. This module converts linearly polarized Gaussian light with pre-defined polarization into a cylindrical vector beam of a specified order, and outputs the radial or angular polarization topology of the cylindrical vector beam through electronically controlled dynamic switching. An electronically controlled drive control unit is electrically connected to the cylindrical vector beam generation and dynamic switching module to achieve electronic switching control. The number of ferroelectric liquid crystal Q-wave plates in the cylindrical vector beam generation and dynamic switching module is consistent with the number of linearly polarized Gaussian light paths output by the multi-source light source and modulation module.

[0040] The cylindrical vector beam generation and dynamic switching module is connected to the output of the polarization setting module. It is used to convert the linearly polarized Gaussian light after polarization setting into a cylindrical vector beam of a specified order and realize the electronically controlled dynamic switching of polarization topology. Its performance directly determines the dynamic control capability and multiplexing capacity of the entire system 100.

[0041] Ferroelectric liquid crystals (FLCs) exhibit significantly superior electro-optic response characteristics compared to traditional nematic liquid crystals. Their molecular orientations can rapidly flip between bistable states under an applied electric field, with response speeds reaching the microsecond level. Furthermore, they require low driving voltages, making them a core material foundation for high-speed, programmable optical field manipulation. Combining geometric phase manipulation mechanisms with fast-response liquid crystal materials (especially FLCs) aims to construct faster, electrically controllable, and programmable structured light generation and modulation systems. This provides a high-performance device foundation for dynamically reconfigurable optical interconnects, meeting the core requirements of rapid channel switching and dynamic reconfiguration in short-range optical communication scenarios. Please refer to [link to relevant documentation]. Figure 2 Ferroelectric liquid crystal Q-wave plates are birefringent devices with an azimuth-dependent spatial optical axis orientation distribution, and can be equivalently regarded as "spatially rotating half-wave plates". The functions of ferroelectric liquid crystal Q-wave plates are as follows: Figure 2 As shown: linearly polarized Gaussian light is converted into a CVB of a specified order; by utilizing the bistable flipping of FLC, rapid switching between radially polarized CVB and angularly polarized CVB is achieved under electronic control.

[0042] In some embodiments, the number of ferroelectric liquid crystal Q-waveplates corresponds one-to-one with (i.e., consistent with) the number of linearly polarized Gaussian optical paths output by the multi-source light source and modulation module, ensuring that each optical signal can independently achieve cylindrical vector beam conversion and polarization topology switching. Relying on the bistable characteristics of the ferroelectric liquid crystal Q-waveplate, the cylindrical vector beam generation and dynamic switching module, through an electronically controlled drive control unit, realizes dynamic switching of the cylindrical vector beam polarization topology—that is, rapidly switching the radial or angular polarization topology of the output beam according to the transmission command. The switching response speed is consistent with the electro-optic response time of the ferroelectric liquid crystal Q-waveplate, enabling microsecond-level rapid switching. Furthermore, the switching process does not affect the order of the cylindrical vector beam or its data carrying capacity, ensuring the continuity and stability of data transmission.

[0043] The transmitting end includes a coaxial multiplexing and beam combining module, which may include at least one beam splitter and / or beam combiner. The coaxial multiplexing and beam combining module is used to coaxially superimpose multiple cylindrical vector beams before sending them into the transmission section. Connected to the output of the cylindrical vector beam generation and dynamic switching module, the coaxial multiplexing and beam combining module coaxially superimposes and combines multiple independent cylindrical vector beams to generate a single multiplexed beam, which is then sent into the transmission section. It is a key module for realizing parallel transmission of multiple data streams. The beam splitter can be a polarization-dependent beam splitter, and the beam combiner can be a polarization-independent beam combiner. This allows for low-loss transmission and beam combining of optical signals with arbitrary polarization states, without beam combining loss or polarization distortion due to differences in beam polarization topology, ensuring that the polarization topology characteristics and data information of each cylindrical vector beam are not destroyed.

[0044] The coaxial multiplexing and beam combining module can include an optical path collimation unit. After being collimated by the optical path collimation unit, the multi-pillar vector beams are sequentially distributed by a polarization-dependent beam splitter, and then coaxially superimposed by a polarization-independent beam combiner, ultimately combining into a single multiplexed beam propagating along the same optical axis. During the beam combining process, each pillar vector beam maintains its own order and polarization topology characteristics, without interfering with each other. The coaxial multiplexing and beam combining module can also integrate a beam combining accuracy adjustment unit. This unit can detect the optical axis consistency of the multiplexed beam in real time and ensure the accuracy of the coaxial superposition of the multi-pillar vector beams by finely adjusting the angles of the beam splitter and beam combiner, avoiding increased transmission loss due to optical axis misalignment and improving the transmission stability of the multiplexed beam.

[0045] Unlike traditional MDM systems that primarily utilize mode order for multiplexing, where the polarization topology of modes of the same order is typically fixed and difficult to flexibly schedule as independent sub-channels, the system 100 of this application introduces the radial / angular polarization topology of CVBs of the same order as a pair of orthogonal sub-modes into the communication multiplexing dimension at the transmitter. Dynamic selection of the two topologies is achieved through polarity control of the FLC Q-plate, while simultaneously expanding the mode library using FLC Q-plates of different orders. The transmitter of the system 100 achieves two-dimensional multiplexing and dynamic configuration of "order × topology" without increasing the number of additional optical paths, improving the size of the mode library and the flexibility of channel scheduling, making the system 100 more closely aligned with the dynamic allocation needs of data center services. The transmitter of the system 100 in this application, through the coordinated operation of a multi-source light source and modulation module, a polarization setting module, a cylindrical vector beam generation and dynamic switching module, and a coaxial multiplexing and beam combining module, combined with the high-speed control characteristics of ferroelectric liquid crystals and modular and electronically controlled design, not only achieves efficient multiplexing of multiple optical signals with data, but also has significant technical advantages such as large transmission capacity, flexible control, high stability, simple structure, and low energy consumption. It provides core support for the stable and efficient operation of the system 100 based on ferroelectric liquid crystals for dynamic multiplexing and demultiplexing of cylindrical vector beams.

[0046] This application presents a dynamic multiplexing and demultiplexing system 100 based on ferroelectric liquid crystals for cylindrical vector beams. The system includes a transmission section, which carries the stable propagation of the multiplexed beam. As the core connection unit between the transmitter and the subsequent receiver, the transmission section ensures the stable propagation of the multiplexed beam output from the transmitter, guaranteeing that the order, polarization topology characteristics, and carried data information of the multiplexed beam are not destroyed during transmission. This achieves efficient and low-distortion transmission of the multiplexed beam from the transmitter to the receiver, laying the foundation for accurate separation of multiple data signals in the subsequent demultiplexing stage.

[0047] The transmission segment is designed to adapt to short-distance transmission scenarios, allowing for flexible selection of two link types: short-distance free-space links and space-fiber hybrid short-distance links, depending on actual application requirements. These two link types can be used individually or in combination. When the transmission scenario demands high flexibility in link deployment and requires a short transmission distance, the short-distance free-space link can be selected. When the transmission scenario demands high stability and anti-interference capabilities of the multiplexed beam, and there are short-distance cross-device and cross-regional transmission needs, the space-fiber hybrid short-distance link can be selected. Both link types in the transmission segment are compatible with the multiplexed beam characteristics output from the 100 transmitters of this system, ensuring the stability and integrity of the multiplexed beam during transmission. They also exhibit good optical path matching with the transmitter and receiver, eliminating the need for additional complex adaptation modules.

[0048] This application presents a dynamic multiplexing and demultiplexing system 100 based on ferroelectric liquid crystals for cylindrical vector beams. The system includes a receiver end, which performs dynamic selective demultiplexing, polarization separation, and coupled reception of the multiplexed beam. The receiver end interfaces with the multiplexed beam output from the transmission section, performing dynamic selective demultiplexing, polarization separation, and coupled reception. It separates, restores, and receives the target optical signals carrying multiple data streams from the multiplexed beam, ultimately achieving accurate data signal analysis and index measurement. Working in conjunction with the transmitter and transmission section, it forms a complete "transmission-reception" link, ensuring a closed-loop data transmission for the entire system 100. The receiver end adopts a modular architecture design, sequentially including a dynamic demultiplexing module, a polarization separation module, and a single-mode coupling and receiving module. These modules are connected sequentially via optical paths, and the electronically controlled drive control unit is electrically connected to the dynamic demultiplexing module to achieve electronic control and regulation of the demultiplexing process.

[0049] The receiving end includes a dynamic demultiplexing module. One end of the dynamic demultiplexing module is connected to the transmission section, and the other end is connected to the polarization separation module. The dynamic demultiplexing module is used to selectively inversely transform the target order cylindrical vector beam channel. When matched, it outputs a zero-order beam; when mismatched, it maintains a higher-order or non-zero-order beam. The electronically controlled drive control unit is electrically connected to the dynamic demultiplexing module to realize state switching and target channel addressing. The core function of the dynamic demultiplexing module is to selectively inversely transform the target order cylindrical vector beam channel in the multiplexed beam, realizing dynamic selective demultiplexing of multiple cylindrical vector beams, accurately locating and restoring the target data channel transmitted by the transmitter, and solving the technical pain points of traditional demultiplexing modules such as poor targeting and inflexible switching.

[0050] The dynamic demultiplexing module comprises a cascaded structure of multiple sets of ferroelectric liquid crystal Q-plates (FLC Q-plates) and liquid crystal variable retarders (LCVRs). The Q-plate is a birefringent device with a continuously rotating spatial optical axis distributed along its azimuth angle, used to generate / inverse transform structured light such as CVBs. The number of cascaded structures matches the number of optical paths in the transmitter's cylindrical vector beam generation and dynamic switching module, as well as the number of multiplexed beam channels transmitted in the transmission segment, ensuring that each target channel can achieve independent selective demultiplexing. The cascade relationship between the ferroelectric liquid crystal Q-plates and liquid crystal variable retarders in the dynamic demultiplexing module matches the polarization topology switching logic of the cylindrical vector beam generation and dynamic switching module—that is, the control logic of the cascaded structure corresponds one-to-one with the switching logic of the transmitter's beam polarization topology, ensuring that the demultiplexing process can accurately match the transmitter's multiplexing logic, achieving precise inverse transformation of the target beam. Specifically, the matching is achieved as follows: the order of the ferroelectric liquid crystal Q-wave plate is consistent with the order of the corresponding cylindrical vector beam at the transmitting end, and the phase compensation of the liquid crystal variable delay device cancels out the phase delay of the ferroelectric liquid crystal Q-wave plate at the transmitting end.

[0051] The LCVR provides a voltage-controllable phase delay δ, which is preferably configured in this invention as at least two switchable equivalent operating states: equivalent half-wave delay (δ=λ / 2) state / equivalent full-wave delay (δ=λ) state; and cascaded with a Q-plate to construct selective logic for "order transformation / cancellation", enabling the target order channel to be inversely transformed into a zero-order (Gaussian-like) output for subsequent single-mode fiber coupling. Please refer to... Figure 3a When there is no voltage, the liquid crystal molecules are constrained by the alignment layer and are oriented in a planar manner, resulting in a large effective birefringence and a large phase retardation in the device; please refer to Figure 3b When a voltage V=Vmax is applied, the molecules tilt / rearrange under the action of the electric field, the birefringence decreases, and the phase delay decreases accordingly, thus realizing the electronic control adjustment of the phase delay.

[0052] The working principle of the dynamic demultiplexing module is as follows: When the receiver receives the multiplexed beam, the electronically controlled drive control unit adjusts the cascaded structure in the dynamic demultiplexing module according to the preset target channel command, so as to achieve selective addressing and state switching of the target order cylindrical vector beam channel; when the cascaded structure matches a target order cylindrical vector beam in the multiplexed beam, the cylindrical vector beam will be selectively inversely transformed and restored to a zero-order beam; when the cascaded structure does not match a cylindrical vector beam in the multiplexed beam, the cylindrical vector beam will remain in a high-order or non-zero-order state and cannot enter the subsequent polarization separation and reception stage, thereby realizing the accurate selection and demultiplexing of the target order cylindrical vector beam channel.

[0053] The receiver includes a polarization separation module, which comprises a polarization-dependent beam splitter. This module separates the orthogonal polarization components corresponding to radial and angular polarizations and outputs them to different ports. Connected to the output of the dynamic demultiplexing module, the polarization separation module performs polarization separation on the target zero-order beam output from the dynamic demultiplexing module, separating the orthogonal polarization components corresponding to radial and angular polarizations. It then outputs these different polarization components to different ports, providing a precisely polarized beam for subsequent single-mode coupling and reception. This ensures that the target data signal corresponding to each polarization component can be received and analyzed independently, avoiding data analysis errors caused by polarization component mixing.

[0054] The core component of the polarization separation module is a polarization-dependent beam splitter. This beam splitter efficiently separates orthogonal polarization components in a beam, with no polarization distortion and low energy loss during the separation process, ensuring that the data information carried by the polarization components is not destroyed. The orthogonal polarization components separated by the polarization separation module correspond precisely to the orthogonal linear polarization input provided by the transmitter's polarization setting module. The linear polarization input directions provided by the polarization setting module are mutually orthogonal, ensuring that the polarization separation logic at the receiver and the polarization setting logic at the transmitter are completely matched, achieving accurate data signal reconstruction.

[0055] The specific working process of the polarization separation module is as follows: After the target zero-order beam output by the dynamic demultiplexing module enters the polarization-dependent beam splitter, the polarization-dependent beam splitter separates the orthogonal polarization components corresponding to radial polarization and angular polarization in the beam one by one, and transmits them to different output terminals of the polarization separation module. Each output terminal corresponds to one polarization component, ensuring that the subsequent single-mode coupling and receiving module can receive and process each polarization component individually.

[0056] The receiving end includes single-mode coupling and receiving modules, which are connected to each end of the polarization separation module. These modules couple the target beam to a single-mode fiber coupler and send it to the optical receiver, performing measurements of indicators such as bit error rate. The single-mode coupling and receiving modules are also connected to the outputs of the polarization separation module via optical paths. Each output of the polarization separation module is connected to a set of single-mode coupling and receiving modules, coupling each target beam output from the polarization separation module to a single-mode fiber coupler and sending it to the optical receiver. This completes the reception and reconstruction of the optical signal, as well as the measurement of key transmission indicators such as bit error rate, providing support for evaluating the system's data transmission performance.

[0057] The single-mode coupling and receiving module may include a single-mode fiber coupler and an optical receiver. The single-mode fiber coupler and the optical receiver are fixedly connected via an optical path. The single-mode fiber coupler can be a high-coupling-efficiency device; for example, its coupling efficiency can be no less than 90%, preferably 90%~98%. This configuration can effectively reduce energy loss during the coupling process of the target beam, ensuring that the optical signal can be transmitted to the optical receiver efficiently, and avoiding signal distortion or increased bit error rate due to coupling loss. The optical receiver can be a high-speed response receiving device, with a response speed matching the response speed of the electro-optic modulator at the transmitting end. It can quickly receive the optical signal transmitted by the single-mode fiber coupler and restore the optical signal to the electrical domain data signal. It also integrates a bit error rate measurement unit, which can measure key indicators such as the bit error rate and signal-to-noise ratio of data transmission in real time, providing real-time feedback on the system's transmission performance.

[0058] The working process of the single-mode coupling and receiving module is as follows: Each orthogonal polarization component output by the polarization separation module enters the corresponding single-mode fiber coupler. After the single-mode fiber coupler efficiently couples the light beam, it is transmitted to the optical receiver. After receiving the optical signal, the optical receiver completes the optical-to-electric conversion, restoring the optical signal to the original electrical domain data signal. At the same time, through the built-in measurement unit, it completes the real-time measurement of indicators such as bit error rate, realizes the evaluation of the data signal reception and transmission performance, and finally completes the data transmission closed loop of the entire system.

[0059] The receiver, through the coordinated operation of the dynamic demultiplexing module, polarization separation module, single-mode coupling and receiving module, combined with the precise control of the electronically controlled drive control unit, achieves dynamic selective demultiplexing, polarization separation and efficient coupling reception of the multiplexed beam. Furthermore, the design of each module is strictly matched with the technical logic of the transmitter and transmission segment, ensuring the overall coordination and stability of the system 100. This effectively solves the technical pain points of traditional receivers, such as poor demultiplexing targeting, low polarization separation accuracy, and insufficient coupling efficiency, providing core terminal support for the accuracy and efficiency of data transmission in the system 100. At the receiver, the system 100 of this application uses an "FLC Q-plate + LCVR group" to achieve rapid dynamic gating and switching of any CVB channel (without changing the optical path structure): when the LCVR is in a half-wave / full-wave equivalent state, it works with multi-level Q-plates to add / subtract the order and cancel selective modes, making the target channel output zero-order (Gaussian-like) for single-mode fiber coupling, and then the PBS separates the radial / angular polarization components.

[0060] This application presents a dynamic multiplexing and demultiplexing system 100 based on ferroelectric liquid crystal cylindrical vector beams. The system includes an electronically controlled drive control unit, a transmitter, a transmitter, a receiver, and the electronically controlled drive control unit collaboratively to achieve electronic reconstruction of multi-channel parallel communication and arbitrary channel switching. The electronically controlled drive control unit is electrically connected to the transmitter and receiver. It accurately outputs electrical signals, receives external control commands, and performs command parsing and execution. This collaboratively enables the transmitter, transmitter, and receiver to achieve electronic reconstruction of multi-channel parallel communication and arbitrary channel switching, ensuring coordinated operation and precise control of all modules within the entire system 100.

[0061] The electronically controlled drive control unit outputs electrical signals to synchronously control the polarization topology switching of the column vector beam generation and dynamic switching module, and the target channel addressing of the dynamic demultiplexing module. This synchronous control logic ensures that after the polarization topology switching of a certain column vector beam at the transmitting end, the corresponding dynamic demultiplexing module at the receiving end can synchronously complete the target channel addressing and state switching, realizing precise linkage between "transmit and receive" and ensuring the stability of multi-channel parallel communication.

[0062] The electronically controlled drive control unit outputs precise electrical signals to achieve synchronous and independent control of the core modules of the transmitter and receiver. The core control logic is divided into two dimensions to ensure the accuracy and synchronization of the control. The electronically controlled drive control unit supports the subdivided independent control of each module: based on programmable design, it can achieve precise control for different control requirements of the transmitter and receiver. (1) Independent control of the transmitter: The electronically controlled drive control unit can receive external control signals to achieve independent control of each ferroelectric liquid crystal Q-wave plate in the transmitter column vector beam generation and dynamic switching module. By outputting independent electrical control signals to each ferroelectric liquid crystal Q-wave plate, the polarization topology of the corresponding optical path column vector beam can be flexibly adjusted, thereby realizing synchronous or asynchronous switching of the polarization topology of multiple column vector beams. Synchronous switching can meet the requirement of simultaneous adjustment of polarization topology of multiple channels, while asynchronous switching can realize independent adjustment of a single path channel, which greatly improves the dynamic multiplexing flexibility of this system and adapts to the adjustment requirements of different transmission capacities and transmission rates. (2) Independent control of the receiving end: The electronically controlled drive control unit can receive external control commands to realize the state switching of the dynamic demultiplexing module of the receiving end and target channel addressing. According to the external command requirements, it can realize the individual demultiplexing of a single target channel to accurately restore a target data signal; it can also realize the synchronous demultiplexing of multiple target channels to restore multiple parallel data signals at the same time. Moreover, the switching response speed is consistent with the response speed of the ferroelectric liquid crystal Q wave plate of the transmitting end, ensuring the speed and flexibility of the demultiplexing process. It can flexibly adapt to different target channel selection requirements in short-distance transmission scenarios and improve the system's adaptability.

[0063] In summary, unlike traditional schemes that employ slow spatial modulators such as static Q-plates / static waveplates or LCOS / SLMs for structured light modulation, which suffer from slow response and complex driving, the System 100 of this application uses liquid crystal devices to construct a high-speed electrically controlled geometric phase structured light processing unit. It utilizes FLC bistable switching and LC tilt angle control to achieve polarization control and phase delay control, forming an integrable, electrically controllable, and reusable structured light system. The System 100 utilizes ferroelectric liquid crystal bistable switching for rapid switching, achieving low-voltage microsecond-level switching without mechanical movement, significantly improving switching speed and long-term stability, providing the hardware foundation for the System 100's reconfigurability. The System 100 uses a small number of adjustable devices to cover multi-order CVB selective demultiplexing, reducing the number of devices and the complexity of the System 100, achieving a combination of capacity advantages and switching flexibility. It can perform channel reallocation and congestion avoidance on demand, reducing resource waste and latency jitter caused by fixed channel configurations.

[0064] Please see Figure 1 In a specific embodiment of this application, the number of transmitters is four, namely the first transmitter 11 (corresponding to...) Figure 1 TX1 in the middle), the second transmitter 12 (corresponding to Figure 1 TX2 in the middle), the third transmitter 13 (corresponding to Figure 1 TX3 in the middle), the fourth transmitter 14 (corresponding to Figure 1 The four transmitters (TX4) have identical structures, operate independently, and together constitute the multi-signal transmission link of this system. There are seven ferroelectric liquid crystal Q-plates (FLC Q-plates), namely the first ferroelectric liquid crystal Q-plate 21 (corresponding to...). Figure 1 The FLC Q-plate 1 and the second ferroelectric liquid crystal Q-wave plate 22 (corresponding to) Figure 1 The FLC Q-plate 2 and the third ferroelectric liquid crystal Q-wave plate 23 (corresponding to) Figure 1 The FLC Q-plate3), the fourth ferroelectric liquid crystal Q-wave plate 24 (corresponding to) Figure 1 The FLC Q-plate4), the fifth ferroelectric liquid crystal Q-wave plate 25 (corresponding to) Figure 1 The FLC Q-plate5), the sixth ferroelectric liquid crystal Q-wave plate 26 (corresponding to) Figure 1 The FLC Q-plate 6 and the seventh ferroelectric liquid crystal Q-wave plate 27 (corresponding to) Figure 1 The FLC Q-plate 7 is used in the receiver. The first four FLC Q-plates (FLC Q-plate 1~4) are adapted to the four transmitters (TX1~TX4), and the last three FLC Q-plates (FLC Q-plate 5~7) are used for cascaded inverse transformation at the receiver. There are three beam combiners, namely the first beam combiner 31 (corresponding to...). Figure 1BS1), the second bundle combiner 32 (corresponding to) Figure 1 BS2 in the middle), the third bundle combiner 33 (corresponding to) Figure 1 In the above, BS1 to BS3 work together to achieve hierarchical coaxial beam combining of four transmitted signals. BS1 to BS3 all use polarization-dependent beam splitters / polarization-independent beam combiners to avoid polarization crosstalk during beam combining. There are two liquid crystal variable delay units, namely the first liquid crystal variable delay unit 41 (corresponding to...). Figure 1 LCVR1) and the second liquid crystal variable delay unit 42 (corresponding to Figure 1 LCVR1 and LCVR2 are used at the receiver to construct the matching inverse transform condition of the target channel; the number of beam splitters 51 is one, i.e. Figure 1 The PBS shown is used at the receiving end to separate the orthogonal polarization components corresponding to radial and angular polarization; there are two receiving ends, namely the first receiving end 61 (corresponding to...). Figure 1 RX1 in the middle), the second receiver 62 (corresponding to Figure 1 RX2), RX1 and RX2 are used to receive the target signal after polarization separation and complete the detection.

[0065] The specific signal transmission and device coordination workflow is as follows: The linearly polarized Gaussian optical signal output from TX1 is converted into a CVB of the target order by FLC Q-plate1, and its polarization topology can be switched by the electronically controlled drive control unit. Simultaneously, the optical signal output from TX2, after CVB conversion and topology switching by FLC Q-plate2, is input to BS1 along with the optical signal from TX1 processed by FLC Q-plate1, completing the initial beam combining of the two CVBs. At the same time, the optical signal output from TX3 is processed by FLC Q-plate3, and the optical signal output from TX4 is processed by FLC Q-plate4. The two processed CVB signals are then input to BS2, completing the initial beam combining of the other two CVBs. The two combined signals output from BS1 and BS2 are further input to BS3, where the four CVB signals are finally coaxially superimposed to form a single multiplexed beam, which is then output to the dynamic demultiplexing module at the receiving end. After the multiplexed beam is output from BS3, it passes through FLC Q-plate5, LCVR1, FLC Q-plate6, LCVR2, and FLC Q-plate7 in a preset cascade order to complete the selective inverse transformation of the target channel. The electronically controlled drive unit controls LCVR1 and LCVR2 to be in equivalent half-wave or equivalent full-wave states, respectively, based on the order and polarization state of the target CVB. This, combined with FLC Q-plate5, FLC Q-plate6, and FLC Q-plate7, achieves order addition / subtraction and selective mode cancellation, converting the target channel CVB into a zero-order Gaussian-like beam, while non-target channels remain in a higher-order or non-zero-order state. The beam processed by the dynamic demultiplexing module is input to the PBS, where the PBS separates the orthogonal polarization components corresponding to the radial and angular polarizations of the CVB. These two polarization components are output from RX1 and RX2, respectively. Finally, the single-mode coupling and receiving modules corresponding to RX1 and RX2 complete beam coupling and signal detection, measuring power, crosstalk, and bit error rate, thus completing the signal transmission closed loop of the multiplexing and demultiplexing process. The quantity, connection, and signal flow of the aforementioned devices not only meet the requirements of four-way parallel communication, but also achieve multi-channel dynamic control through a small number of adjustable devices, effectively reducing system complexity and improving channel scheduling flexibility.

[0066] Please see Figure 4 This application also proposes a method for using the ferroelectric liquid crystal-based cylindrical vector beam dynamic multiplexing / demultiplexing system 100. This method utilizes the transmitter, transmission section, receiver, and electronically controlled drive control unit of the ferroelectric liquid crystal-based cylindrical vector beam dynamic multiplexing / demultiplexing system 100 to achieve electronic reconstruction of multi-channel parallel communication and arbitrary channel switching, ensuring efficient, stable transmission and accurate resolution of multiple data signals. The method includes the steps of: S100 dynamic multiplexing at the transmitter and S200 dynamic demultiplexing at the receiver.

[0067] The core purpose of S100 transmitter dynamic multiplexing is to convert multiple original electrical domain data signals into multiple cylindrical vector beams with different orders and dynamically switchable polarization topologies through the collaborative processing of various modules at the transmitter, and then coaxially combine them into a multiplexed beam for output to the transmission section.

[0068] The S100 transmitter dynamic multiplexing process includes the following steps: S110 multi-channel optical signal generation and modulation. N optical carriers (N being a positive integer) are generated through a multi-channel light source and modulation module, and a digital modulation signal is loaded onto each optical carrier to output a multi-path polarized Gaussian beam. In S110, the transmitter's multi-channel light source and modulation module is activated, generating N optical carriers through a multi-channel independent light source array within the module. Simultaneously, the digital modulation signal to be transmitted is loaded onto each corresponding optical carrier via a high-speed electro-optic modulator corresponding to each optical carrier in the multi-channel light source and modulation module, completing the conversion from electrical signal to optical signal, and ultimately outputting an N-path polarized Gaussian beam. In S110, the wavelength of each path polarized Gaussian beam remains consistent (or meets the specific wavelength requirements of the transmission segment), and after loading the digital modulation signal, the polarization state stability of the optical signal must be ensured to avoid introducing polarization distortion during data loading. Furthermore, the power of each path polarized Gaussian beam can be independently adjusted through the optical power adjustment unit of the multi-channel light source and modulation module to ensure power balance across channels after subsequent beam combining.

[0069] The S100 transmitter dynamic multiplexing includes the following steps: S120 Input polarization setting: Through the polarization control or polarization holding device in the polarization setting module, each line-polarized Gaussian beam is set to a predetermined linear polarization direction, serving as the input condition for cylindrical vector beam generation and radial / angular polarization sub-state definition. The N-line-polarized Gaussian beam output from step S110 is synchronously input to the transmitter's polarization setting module. Through the polarization control or polarization holding device in the polarization setting module, the polarization state of each line-polarized Gaussian beam is calibrated and its direction is set, uniformly setting it to a predetermined linear polarization direction, serving as the input condition for subsequent cylindrical vector beam generation and radial / angular polarization sub-state definition. In S120, the predetermined linear polarization direction of each line-polarized Gaussian beam is precisely controllable. Each polarization adjustment unit in the polarization setting module operates independently, avoiding polarization interference between multiple beams and ensuring that each line-polarized Gaussian beam meets the polarization requirements for subsequent cylindrical vector beam conversion.

[0070] The S100 transmitter dynamic multiplexing includes the following steps: S130 cylindrical vector beam generation and topology dynamic switching, where each line-polarized Gaussian beam is converted into a target-order cylindrical vector beam by a ferroelectric liquid crystal Q-waveplate of the corresponding order in the cylindrical vector beam generation and dynamic switching module; the ferroelectric liquid crystal Q-waveplate is subjected to bipolar drive and the bipolar drive voltage polarity is switched by the electronically controlled drive control unit, realizing the rapid switching between radial and angular polarization of the cylindrical vector beam, forming a dynamically selectable channel with two sub-states of the same order. The line-polarized Gaussian beams after polarization setting in step S120 are input to the corresponding-order ferroelectric liquid crystal Q-waveplates in the transmitter's cylindrical vector beam generation and dynamic switching module, and the phase delay modulation effect of the ferroelectric liquid crystal Q-waveplate converts each line-polarized Gaussian beam into a preset target-order cylindrical vector beam. Subsequently, the electronically controlled drive control unit is activated. This unit applies a bipolar driving voltage to each ferroelectric liquid crystal Q-wave plate. By switching the polarity of the bipolar driving voltage, the corresponding column vector beam is rapidly switched between radial and angular polarization, thus forming a dynamically selectable channel with two sub-states of the same order (radial polarization sub-state and angular polarization sub-state). Each channel with two sub-states of the same order corresponds to an independent data channel, increasing the multiplexing capacity of the system by 100%. In S130, the dynamic switching speed of the two sub-states of the same order is determined by the switching speed of the bipolar driving voltage output by the electronically controlled drive control unit. Combined with the high-speed electro-optic response characteristics of the ferroelectric liquid crystal Q-wave plate, microsecond-level rapid switching can be achieved. Furthermore, the switching process does not affect the order of the column vector beam or the data carrying capacity, ensuring the continuity and stability of data transmission.

[0071] The S100 transmitter-side dynamic multiplexing process includes the following steps: S140 coaxial beam combining and multiplexing, where multiple cylindrical vector beams are coaxially superimposed using beam splitters and / or combiners in the coaxial multiplexing and combining module to form a multiplexed beam, which is then output to the transmission section. The N-way cylindrical vector beams, dynamically switchable in polarization topology and generated in step S130, are synchronously input to the transmitter-side coaxial multiplexing and combining module. Through beam splitters and / or combiners in this module, the multiple cylindrical vector beams undergo optical path distribution and coaxial superposition, ensuring that each cylindrical vector beam propagates along the same optical axis and maintains its order, polarization topology characteristics, and data information without being destroyed or interfering with each other. Finally, the beams are combined into a single multiplexed beam, which is then stably output to the transmission section, completing the entire transmitter-side dynamic multiplexing process. During the beam combining process of S140, the beam splitter and beam combiner angles can be finely adjusted through the beam combining accuracy adjustment unit of the coaxial multiplexing beam combining module to ensure the accuracy of coaxial superposition of multi-path vector beams, avoid increased transmission loss due to optical axis offset, and ensure the transmission quality of multiplexed beams.

[0072] The core purpose of S200 receiver dynamic demultiplexing is to connect with the multiplexed beam transmitted from the transmission segment. Through the coordinated processing of various modules at the receiver, the cylindrical vector beam of the target channel is accurately separated, restored to a zero-order optical signal, and received and detected. This enables accurate analysis of multiple data signals and measurement of transmission parameters. This step relies on the precise control of the electronically controlled drive control unit.

[0073] The S200 receiver-side dynamic demultiplexing process includes the following steps: S210 Multiplexed beam input: The receiver receives the coaxial multiplexed cylindrical vector beam transmitted from the transmission segment and inputs it into the dynamic demultiplexing module. In S210, the receiver is activated to receive the coaxial multiplexed cylindrical vector beam transmitted from the transmission segment. After ensuring that the multiplexed beam has no significant energy loss, polarization distortion, or optical axis misalignment during transmission, it is accurately input into the receiver's dynamic demultiplexing module to prepare for subsequent demultiplexing processing. When inputting the multiplexed beam into the dynamic demultiplexing module, it is necessary to ensure that the optical axis is aligned with the optical path centerline of the dynamic demultiplexing module to avoid subsequent demultiplexing accuracy degradation and signal distortion due to optical axis misalignment.

[0074] The S200 receiver-side dynamic demultiplexing includes the following steps: S220 Demultiplexing state setting: The electronically controlled drive control unit, based on the order and polarization state of the target cylindrical vector beam, controls the liquid crystal variable delay device in the dynamic demultiplexing module to be in an equivalent half-wave or equivalent full-wave state, thus constructing the matching inverse transformation condition for the target channel. In step S220, the state adjustment of the liquid crystal variable delay device is matched with the polarization topology switching logic of the cylindrical vector beam generation and the dynamic switching module. The electronically controlled drive control unit receives external control commands, obtains the preset order and polarization state of the target cylindrical vector beam, and outputs control signals to the liquid crystal variable delay device in the receiver-side dynamic demultiplexing module according to these target parameters, controlling the liquid crystal variable delay device to be in an equivalent half-wave or equivalent full-wave state, thereby constructing the matching inverse transformation condition for the target channel and ensuring that the optical signal of the target channel can be accurately restored subsequently. In S220, the state adjustment of the liquid crystal variable delay unit is strictly matched with the polarization topology switching logic of the transmitter column vector beam generation and dynamic switching module. This ensures that the inverse transformation conditions of demultiplexing correspond one-to-one with the multiplexing transformation conditions of the transmitter, avoiding demultiplexing failure or data errors caused by logic mismatch.

[0075] The S200 receiver dynamic demultiplexing includes the following steps: S230, Q-plate cascade inverse transformation and selective cancellation, the multiplexed beam passes through the cascaded component of the dynamic demultiplexing module consisting of a ferroelectric liquid crystal Q-waveplate and a liquid crystal variable delayer; when the target channel meets the order matching / cancellation condition, the target cylindrical vector beam is selectively converted into a zero-order Gaussian-like, spatially polarized uniform beam and output; non-target channels, because they do not meet the matching condition, maintain a higher-order or non-zero-order output, which is suppressed in subsequent single-mode coupling, thus achieving selective demultiplexing. The multiplexed beam input in step S210 is then passed into the cascaded component of the dynamic demultiplexing module consisting of a ferroelectric liquid crystal Q-waveplate and a liquid crystal variable delayer. When a target column vector beam in the multiplexed beam meets the order matching / cancellation condition, the target column vector beam is selectively inversely transformed back to a zero-order Gaussian-like, spatially polarized uniform beam and output to the subsequent polarization separation module. Meanwhile, non-target channel column vector beams in the multiplexed beam, not meeting the order matching / cancellation condition, will remain in a high-order or non-zero-order output state. These beams will be suppressed by the single-mode fiber coupler during subsequent single-mode coupling and cannot enter the optical receiver, thus achieving selective demultiplexing of the target channel. In S230, the order of each ferroelectric liquid crystal Q-wave plate in the dynamic demultiplexing module must be consistent with the order of the target column vector beam to be converted from the corresponding linearly polarized Gaussian beam at the transmitting end. Simultaneously, the number of cascaded structures in the dynamic demultiplexing module matches the number N of linearly polarized Gaussian beams output from step S110 at the transmitting end, ensuring that each transmitting channel corresponds to a receiving demultiplexing channel.

[0076] The S200 receiver-side dynamic demultiplexing includes the following steps: S240 polarization separation, where the beam after cascaded inverse transformation is input into the polarization separation module. A beam splitter separates the orthogonal polarization components corresponding to the radial and angular polarizations of the cylindrical vector beam, and outputs these two types of polarization components to different ports. The zero-order beam output from step S230 after cascaded inverse transformation is input into the receiver's polarization separation module. A high-precision polarization-dependent beam splitter in the polarization separation module separates the orthogonal polarization components corresponding to the radial and angular polarizations of the transmitting cylindrical vector beam, and outputs these two different types of polarization components to different output ports of the polarization separation module. This ensures that the target data signal corresponding to each type of polarization component can be received and analyzed independently, avoiding data analysis errors caused by polarization component mixing.

[0077] The S200 receiver-side dynamic demultiplexing process includes the following steps: S250 single-mode coupling and receiving detection. Through the single-mode coupling and receiving module, the zero-order beams output from each port of the polarization separation module are coupled into single-mode fiber couplers and sent to the optical receiver for detection, completing power, crosstalk, and bit error rate measurements. In S250, the receiver-side single-mode coupling and receiving module is activated. Through the single-mode fiber couplers corresponding one-to-one with each output port of the polarization separation module, the zero-order beams output from each port of the polarization separation module are efficiently coupled into the single-mode fiber couplers. Subsequently, the single-mode fiber sends the coupled signal to the optical receiver, which performs optical signal to electrical signal reconstruction. The optical receiver's built-in measurement unit performs real-time measurements of key indicators such as power, crosstalk, and bit error rate during data transmission, providing feedback on the system's transmission performance. This ultimately completes the entire dynamic multiplexing, transmission, and demultiplexing process of the system.

[0078] The usage of this system 100 strictly adheres to the structural design and functional characteristics of each module. Each step is logically clear and tightly connected. The S100 transmitter dynamic multiplexing step achieves efficient multiplexing of multiple data streams, and the S200 receiver dynamic demultiplexing step achieves accurate parsing of target data. Throughout the process, under the overall control of the electronically controlled drive control unit, the control of the transmitter and receiver is synchronized and logically matched, effectively leveraging the advantages of this system 100, such as large transmission capacity, flexible control, and high stability, making it suitable for various application scenarios of short-distance multi-channel parallel communication.

Claims

1. A dynamic multiplexing and demultiplexing system for cylindrical vector beams based on ferroelectric liquid crystals, characterized in that, It includes a transmitter, a transmission segment, a receiver, and an electronically controlled drive control unit. The transmitter, the transmission segment, the receiver, and the electronically controlled drive control unit work together to complete the electronic reconstruction of multi-channel parallel communication and arbitrary channel switching. The transmitter is used to convert multiple Gaussian light signals carrying data into cylindrical vector beams of different orders and polarization topologies, and coaxially combine them into a multiplexed beam. The transmitter includes a multi-source light source and modulation module, a polarization setting module, a cylindrical vector beam generation and dynamic switching module, and a coaxial multiplexing and beam combining module. The multi-source light source and modulation module outputs multi-path polarized Gaussian light and loads data signals; the polarization setting module provides stable orthogonal linear polarization input for each path polarized Gaussian light, serving as a reference for cylindrical vector beam generation and sub-state definition; the cylindrical vector beam generation... The beam generation and dynamic switching module includes multiple ferroelectric liquid crystal Q-wave plates. The cylindrical vector beam generation and dynamic switching module is used to convert linearly polarized Gaussian light with polarization set into a cylindrical vector beam of a specified order, and outputs the radial or angular polarization topology of the cylindrical vector beam through electronically controlled dynamic switching. The electronically controlled drive control unit is electrically connected to the cylindrical vector beam generation and dynamic switching module to realize electronically controlled switching control. The coaxial multiplexing and beam combining module includes a beam splitter and / or a beam combiner. The coaxial multiplexing and beam combining module is used to coaxially superimpose multiple cylindrical vector beams and send them into the transmission section. The transmission segment is used to carry the stable propagation of the multiplexed beam; The receiving end is used for dynamic selective demultiplexing, polarization separation, and coupled reception of the multiplexed beam. The receiving end includes a dynamic demultiplexing module, a polarization separation module, and a single-mode coupling and receiving module. The dynamic demultiplexing module includes a ferroelectric liquid crystal Q-wave plate and a liquid crystal variable delay unit arranged in a specific cascade relationship. One end of the dynamic demultiplexing module is connected to the transmission section, and the other end is connected to the polarization separation module. The dynamic demultiplexing module is used to perform selective inverse transformation on the target order cylindrical vector beam channel. When the target order cylindrical vector beam channel satisfies order matching / counteracting... When the condition is eliminated, a zero-order beam is output; when the non-target order cylindrical vector beam channel does not meet the order matching / cancellation condition, a higher-order or non-zero-order beam is maintained. The electronically controlled drive control unit is electrically connected to the dynamic demultiplexing module to realize state switching and target channel addressing. The polarization separation module includes a polarization beam splitter, which is used to separate the orthogonal polarization components corresponding to radial and angular polarization and output them to different ports. The single-mode coupling and receiving module is connected to each end of the polarization separation module and is used to couple the target beam to the single-mode fiber coupler and send it to the optical receiver to complete the index measurement.

2. The dynamic multiplexing and demultiplexing system for cylindrical vector beams based on ferroelectric liquid crystals according to claim 1, characterized in that, The linear polarization input directions provided by the polarization setting module are mutually orthogonal.

3. The dynamic multiplexing and demultiplexing system for cylindrical vector beams based on ferroelectric liquid crystal according to claim 1, characterized in that, The transmission segment is a short-range free-space link; and / or, the transmission segment is a space-fiber hybrid short-range link.

4. The dynamic multiplexing and demultiplexing system for cylindrical vector beams based on ferroelectric liquid crystal according to claim 1, characterized in that, The number of ferroelectric liquid crystal Q-wave plates in the cylindrical vector beam generation and dynamic switching module is the same as the number of linearly polarized Gaussian optical paths output by the multi-source light source and modulation module.

5. The dynamic multiplexing and demultiplexing system for cylindrical vector beams based on ferroelectric liquid crystal according to claim 1, characterized in that, The cascade relationship between the ferroelectric liquid crystal Q-wave plate and the liquid crystal variable delay unit in the dynamic demultiplexing module matches the polarization topology switching logic of the cylindrical vector beam generation and dynamic switching module.

6. The dynamic multiplexing and demultiplexing system for cylindrical vector beams based on ferroelectric liquid crystal according to claim 1, characterized in that, The beam splitter is a polarization-dependent beam splitter, and the beam combiner is a polarization-independent beam combiner.

7. The dynamic multiplexing and demultiplexing system for cylindrical vector beams based on ferroelectric liquid crystal according to claim 1, characterized in that, The single-mode coupling and receiving module includes the single-mode fiber coupler and the optical receiver.

8. The dynamic multiplexing and demultiplexing system for cylindrical vector beams based on ferroelectric liquid crystal according to claim 1, characterized in that, The electronically controlled drive control unit outputs electrical signals to synchronously control the polarization topology switching of the cylindrical vector beam generation and dynamic switching module and the target channel addressing of the dynamic demultiplexing module.

9. A method of using a dynamic multiplexing and demultiplexing system for cylindrical vector beams based on ferroelectric liquid crystals according to any one of claims 1 to 8, characterized in that, The steps include: dynamic multiplexing at the transmitting end and dynamic demultiplexing at the receiving end; The dynamic multiplexing of the transmitter includes the following steps: The system generates and modulates multiple optical signals, generating N optical carriers through the multiple light sources and modulation modules, and loading digital modulation signals onto each optical carrier to output a multi-path polarized Gaussian beam. The input polarization setting, through the polarization control or polarization holding device in the polarization setting module, sets each linearly polarized Gaussian beam to a predetermined linear polarization direction, which serves as the input condition for the generation of cylindrical vector beams and radial / angular nipple states; The cylindrical vector beam generation and topology dynamic switching module converts each path-polarized Gaussian beam into a target-order cylindrical vector beam by passing through a ferroelectric liquid crystal Q-waveplate of the corresponding order in the module. The electronically controlled drive control unit applies bipolar drive to the ferroelectric liquid crystal Q-waveplate and switches the bipolar drive voltage polarity to achieve rapid switching between radial and angular polarization of the cylindrical vector beam, forming a dynamically selectable channel with two sub-states of the same order. Coaxial beam combining and multiplexing involves coaxially superimposing multiple cylindrical vector beams through beam splitters and / or beam combiners in the coaxial multiplexing and multiplexing module to form a multiplexed beam, which is then output to the transmission segment. The dynamic demultiplexing at the receiving end includes the following steps: Multiplexed beam input: Receives the coaxial multiplexed cylindrical vector beam transmitted by the transmission segment and inputs it into the dynamic demultiplexing module; In the demultiplexing state setting, the electronically controlled drive control unit controls the liquid crystal variable delay device in the dynamic demultiplexing module to be in an equivalent half-wave or equivalent full-wave state according to the order and polarization state of the target column vector beam, thereby constructing the matching inverse transformation conditions of the target channel. The Q-plate cascaded inverse transformation and selective cancellation are performed, and the multiplexed beam passes through the cascaded component of the dynamic demultiplexing module, which consists of a ferroelectric liquid crystal Q-waveplate and a liquid crystal variable delayer. When the target channel meets the order matching / cancellation condition, the target cylindrical vector beam is selectively converted into a zero-order Gaussian-like, spatially polarized uniform beam and output. Non-target channels, because they do not meet the matching condition, maintain a high-order or non-zero-order output and are suppressed in the subsequent single-mode coupling process, thus achieving selective demultiplexing. Polarization separation involves inputting the beam after cascaded inverse transformation into the polarization separation module, where a beam splitter separates the orthogonal polarization components corresponding to the radial and angular polarizations of the cylindrical vector beam, and outputs the two types of polarization components to different ports. The single-mode coupling and receiving module couples the zero-order beams output from each port of the polarization separation module into the single-mode fiber coupler and sends them to the optical receiver for detection, thus completing the measurement of power, crosstalk, and bit error rate.

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