177 results about "Birefraction" patented technology

The invention relates to an ultralow-loss hollow-core anti-resonance optical fiber with a birefringence structure, which comprises an outer cladding and an inner cladding, the inner cladding is composed of anti-resonance structure units, the anti-resonance structure units are arranged along the circumferential direction of the inner wall of the outer cladding and are connected with the inner wall of the outer cladding, the inner cladding comprises four anti-resonance structure units, and the anti-resonance structure units are arranged along the circumferential direction of the inner wall of the outer cladding and are connected with the inner wall of the outer cladding. The four anti-resonance structure units are evenly distributed at intervals in the circumferential direction and comprise two long-axis anti-resonance structure units and two short-axis anti-resonance structure units, the two long-axis anti-resonance structure units are symmetrically arranged on the two sides of the inner wall of the outer cladding layer, and the two short-axis anti-resonance structure units are symmetrically arranged on the other two sides of the inner wall of the outer cladding layer. A central cavity wrapped by an inner wrapping layer formed by the four anti-resonance structure units forms an elliptical fiber core with a long axis and a short axis. According to the invention, the transmission loss can be reduced while the high birefringence performance is maintained, the shape of each part of the microstructure cladding is regular, and the preparation is convenient.

The invention relates to the technical field of optical fiber device manufacturing, and discloses a femtosecond laser inscribing low-polarization-dependent-loss optical fiber grating method and system, and the method comprises the steps: firstly, synthesizing an initial phase comprising a flat-topped beam phase, an astigmatism correction phase and a defocus phase, and loading the initial phase to a spatial light phase modulator; therefore, a preset circular flat-top focusing light spot is generated. Secondly, collecting a three-dimensional light field image sequence of a focusing light spot in a low-power detection mode, reconstructing light intensity distribution, extracting effective focal depth and ovality characteristic parameters, dynamically optimizing a phase through a closed-loop feedback mechanism until light field characteristics reach a preset target, and obtaining an optimized phase; and finally, loading an optimized phase in a high-power inscribing mode, and controlling the axial scanning of the optical fiber to inscribe the grating. Accurate active regulation and control of the three-dimensional shape of the focused light field and closed-loop self-optimization of process parameters are realized, birefringence caused by anisotropy of a refractive index modulation area is inhibited from a physical mechanism, and polarization dependent loss of the fiber bragg grating is fundamentally reduced.

The invention discloses a broadband nonlinear frequency converter which comprises a silicon dioxide coating layer, an x-cut lithium niobate film layer, a silicon dioxide buffer layer and a silicon substrate layer from top to bottom, the x-cut lithium niobate film layer is provided with a weak bending ridge waveguide, and the bending angle of the weak bending ridge waveguide is not larger than 5 degrees. According to the invention, birefringence phase matching is realized on the lithium niobate film in a weak bending waveguide form, so that broadband second harmonic generation, birefringence phase matching wavelength and matching angle correlation are realized, and an included angle between a wave vector of transmitted fundamental frequency light and a crystal optical axis is continuously and slightly changed through the weak bending film, so that the broadband second harmonic generation is realized. Therefore, birefringence phase matching of different wavelengths can be realized at different matching angles, and the purpose of broadband matching is achieved.

This disclosure provides an optically active nanocomposite material having a textured substrate and a multilayer optical stack comprising multiple nanosheets. The nanosheets may be chiral and composed of materials such as transition metal chalcogenides, MXenes, or nanocarbon. The optically active nanocomposite material exhibits linear birefringence (LB) and linear dichroism (LD), and optionally circular dichroism (CD). The nanocomposite material also exhibits optical asymmetry. g The factor may be greater than or equal to 1. Furthermore, the nanocomposite material exhibits thermal stability, for example, remaining stable at temperatures above or equal to about 250 °C. This disclosure also provides different methods for preparing such nanocomposite materials using a layer-by-layer self-assembly (LBL) process.

This invention relates to an interferometric measurement method and apparatus for large warp wafers, belonging to the field of optical detection and semiconductor measurement technology. The detection light is polarized and birefringently split to form P-beams and S-beams, which are then further divided into P-reference beams, S-silicon beams, S-reference beams, and P-silicon beams, respectively. By adjusting the spatial orientation of the reference mirror and the wafer under test, and using an aperture for spatial filtering, the P-reference beam and S-silicon beam are allowed to enter the subsequent optical path, while the S-reference beam and P-silicon beam are blocked. The S-silicon beam forms a measurement wavefront carrying information about the surface shape of the wafer under test. The P-reference beam is modulated by a deformable mirror to form a modulated reference wavefront similar to the measurement wavefront. The two form a resolvable interference fringe pattern at the camera. A wavefront sensor measures the surface shape information of the deformable mirror, and a calculation system obtains the surface shape information of the wafer under test based on the deformable mirror surface shape information and the relative surface shape change. This invention can reduce the interference fringe density in the detection of large warp wafers, reduce splicing measurement errors, and improve detection efficiency and accuracy.

The invention relates to the technical field of optical fiber sensing and optical fiber device manufacturing, and discloses a femtosecond laser-inscribing polarization-maintaining fiber grating method and system for vector sensing, and the method comprises the following steps: obtaining a stress region image of a polarization-maintaining fiber through a CCD camera, recognizing the slow axis direction of the fiber through image processing, rotating the fiber, and obtaining the stress region image of the polarization-maintaining fiber; an included angle of 45 degrees is formed between the slow axis direction and a preset incident plane of the femtosecond laser; calculating a conjugate phase of wavefront aberration generated when femtosecond laser penetrates through a fiber coating layer and a cladding and is focused to a fiber core, and generating a phase diagram for loading a spatial light modulator; after being modulated by the spatial light modulator, a light beam emitted by the femtosecond laser enters and is focused on the fiber core along the direction of an included angle of 45 degrees, and a grating structure is formed by combining axial scanning and inscribing. Accurate automatic alignment in the fast and slow axis direction and active compensation of transmission aberration are achieved, refractive index modulation birefringence forming a specific included angle with the inherent birefringence axis of the optical fiber can be effectively induced, and therefore the polarization-maintaining fiber grating with the highly controllable reflection spectrum and the asymmetric double-peak characteristic is engraved.

A kind of ultra-short pulse synchronization testing device and method based on optical Kerr effect. After the high-power density ultra-short pulse of multiple beams to be synchronized passes through optical Kerr medium, induced birefringence effect occurs, which instantaneously changes the polarization characteristics of the reference light beam, and the synchronization between multiple beams of ultra-short pulses is measured by the amplitude or phase change of the reference signal pulse. This method can realize the synchronization measurement of ultra-short pulses with large angle at the target point, and has the advantages of high measurement accuracy, good repeatability and high stability.

A method and system for measuring physical parameters using sensors of the birefringent Fiber Bragg Grating type is provided. In some embodiments, a method and a system for querying a sensor of the birefringent Fiber Bragg Grating (FBG) type (e.g., in birefringent fiber), employing heterodyne optical detection and integrated photonic technology is provided.

The disclosure relates to an optical fiber having multiple light-conducting core regions which extend, mutually spaced, along the longitudinal extension of the optical fiber. In a cross-sectional view, each light-conducting core region is located inside a contiguous signal region which is completely enclosed by a cladding region. Outside the signal region, stress elements of the optical fiber are designed to generate a mechanical stress field in the optical fiber. The stress elements subject each core region to a mechanical stress causing birefringence, and thus polarization-maintaining behavior. One main polarization axis is assigned with each of the core regions. The stress elements may be distributed in groups of two or more stress elements across the cross-section of the optical fiber. In a cross-sectional view, the stress elements have an asymmetrical, namely non-rotationally symmetrical arrangement, which causes the main polarization axes to point in the same direction in all core regions.

Liquid crystal (LC) beam control devices utilize dispersion-shaping (DS) half-wave plates (HWPs) with specific physical properties to allow broadened beams to maintain significantly better color cohesion. This paper describes the advantages of using HWPs with appropriate thickness and birefringence, which makes them inefficient in the blue wavelength spectrum, thus reducing blue photon loss at the center of the broadened beam. This paper also describes combinations of vertically aligned LC cells and DS HWP structures for reducing color separation, accelerating relaxation time, and reducing ground-state scattering.

Three-dimensional reconfigurable vector holographic double-layer cascade super device, design method and equipment belong to the field of holographic technology, solve the problem that reconfiguration of incident wave front often involves changing light source or polarizer operation, which is not only inconvenient but also cannot realize fast switching. The device includes: a hybrid cascade of radiative super surface and birefringent super surface, the intensity and polarization response of hologram in three-dimensional space is reconfigurable and highly customized. The rotatable radiative super surface can be used as an incident wave front modulator to excite the non-rotatable birefringent super surface. By introducing a gradient descent optimization inverse design method, numerical analysis and experimental verification of three-dimensional reconfigurable vector holography are demonstrated in the microwave region. The present application is suitable for integrated encryption devices and holographic display super devices.

The invention discloses an all-optical microwave oscillator based on a non-polarized radial mode LN-PM birefringence effect, which is used for solving the technical problem that an electronic bottleneck of high frequency and low stability is difficult to break through due to the fact that additional noise is extremely easy to generate due to introduction of an electric signal in a traditional photoelectric oscillator, and belongs to the technical field of optical fiber communication and microwave photonics. The birefringence effect of LN-PM is introduced into the microwave photonic oscillator based on forward Brillouin scattering, the gain and loss coefficient of forward Brillouin are controlled by adjusting a polarization controller, and when the gain coefficient is equal to the loss coefficient and greater than a coupling coefficient, the space time is symmetrically broken to obtain single longitudinal mode microwave photon output. Compared with the prior art, the self-excited pumping source is adopted, electric signal modulation is not needed, a single-frequency microwave photon signal which is high in frequency stability, low in phase noise and high in side-mode rejection ratio can be generated, and the system has the advantages of being simple in structure and higher in adaptability and reliability.

Various exemplary embodiments relate to active optical fibers and devices using active optical fibers. An active optical fiber can include a central portion surrounded by a ring-shaped active core. The optical fiber can have a tapered longitudinal profile such that the optical fiber includes a single-mode portion and a multi-mode portion. The ring-shaped core can have a low birefringence, for example, obtained by rotating (fast-rotating) the optical fiber preform during the optical fiber manufacturing. The refractive index of the ring-shaped core can be higher than the refractive index of the central portion and the cladding(s) surrounding the ring-shaped core. The active optical fiber is capable of selectively generating or amplifying an optical mode field having orbital angular momentum (OAM). Furthermore, the optical fiber has a large mode field diameter (MFD) and is insensitive to internal heating or environmental influences.

To provide a laser oscillator capable of obtaining a desired beam profile by continuously changing the beam profile of a laser beam emitted from an optical fiber.SOLUTION: The laser oscillator 90 includes a laser module 10, a condenser lens 42, an optical fiber 80, a polarization adjustment mechanism 30, and a birefringent plate 43. The laser module 10 emits a linearly polarized laser beam LB. The condenser lens 42 condenses the laser beam LB on the optical fiber 80. The optical fiber 80 has a center core 81 and a ring core 83. The polarization adjustment mechanism 30 has a half-wave plate 31 and changes the polarization direction of the laser beam LB. The birefringent plate 43 branches the laser beam LB into the first laser beam LB1 and the second laser beam LB2, and changes the ratio of the light amounts of the first laser beam LA and the second laser beam LA.SELECTED DRAWING: Figure 2A

An image light guide system for conveying a virtual image that includes a first waveguide having a first refractive index and a second waveguide having a second refractive index. The first waveguide includes diffractive optics arranged to in-couple and out-couple image-bearing light beams of a first wavelength range. The second waveguide includes diffractive optics arranged to in-couple and out-couple image-bearing light beams of at least a second wavelength range. An image light guide system for conveying a virtual image that includes a first waveguide having a first refractive index and a second waveguide having a second refractive index. The first waveguide includes diffractive optics arranged to in-couple and out-couple image-bearing light beams of a first wavelength range. The second waveguide includes diffractive optics arranged to in-couple and out-couple image-bearing light beams of at least a second wavelength range.

This invention relates to a germanium-based chiral perovskite second-order nonlinear optical crystalline material, its preparation and application, wherein the chemical formula of the material is ( R -C7H 10 NO)GeI3 and ( S -C7H 10 NO)GeI3, where R -C7H 10 NO is a (R)-2-(1-hydroxyethyl)pyridine cation. S -C7H 10 NO is a (S)-2-(1-hydroxyethyl)pyridine cation. This crystal belongs to the hexagonal crystal system, space group [space group number missing]. P 63, cell parameters a =17.0~18.0 Å, b =17.0~18.0 Å, c =7.0~8.0 Å, unit cell volume V =2000~2200 Å 3 , α = β =90°, gamma =120° Z= 2. Under 1200 nm laser irradiation, the nonlinear optical crystal of the present invention ( R -C7H 10 NO)GeI3 and ( S -C7H 10 The frequency doubling effect of GeI3 powder is 15 times that of KH2PO4; under 2000 nm laser irradiation, the frequency doubling effect of the crystalline material powder is 1.0 times that of KTiOPO4, and both can achieve phase matching. The crystalline material also has a large birefringence, wherein ( R -C7H 10 NO)GeI3 is 0.518 @ 546 nm, ( S -C7H 10 The NO)GeI3 has a wavelength of 0.529 nm at 546 nm and a moderate optical band gap (2.68 eV). The crystalline material of this invention shows significant engineering application value in nonlinear optical applications such as near-infrared laser frequency conversion, optical parametric amplification, and electro-optic signal processing.

This application discloses a method for enhancing the quality of bare fiber sensing signals in vehicle-mounted vibration environments. It relates to the field of fiber optic sensing signal quality enhancement, and utilizes a multi-axis inertial measurement unit and a vibration sensing network to construct a spatiotemporal feature tensor, enabling three-dimensional dynamic perception of the vibration environment. Filtering parameters and gain are dynamically configured based on vibration characteristics to ensure stable signal acquisition under strong vibration conditions. A deep feature decoupling network, combined with vibration environment information, effectively separates noise from the target signal, improving the signal-to-noise ratio. A dynamic compensation module, based on a physical heuristic model, corrects vibration-induced transmission distortion from three dimensions: polarization state, birefringence, and microbending loss, ensuring the physical integrity of the signal. A closed-loop collaborative control mechanism dynamically optimizes the parameters of each module through real-time signal quality feedback, forming an adaptive optimization closed loop. Through spatiotemporal multi-dimensional collaborative processing, high-quality and robust enhancement of bare fiber sensing signals in vehicle-mounted vibration environments is achieved.

A method of accounting for signal noise in a hybrid laser system is described. The hybrid laser system includes a high reflectivity mirror, a nitrogen-vacancy center diamond, a microwave antenna, a dichroic mirror, a half-vertical cavity surface emitting laser (VCSEL), a birefringent filter, an etalon, an output coupler, and a photodiode. The method includes: measuring a shift in a left-hand side frequency as related to an optically detected magnetic resonance (ODMR) frequency peak of an ODMR signal; measuring a shift in a right-hand side frequency as related to the ODMR frequency peak; normalizing the shift in the left-hand side frequency; normalizing the shift in the right-hand side frequency; and comparing the shift in the left-hand side frequency to the shift in the right-hand side frequency to determine a technical noise associated with the ODMR signal.

A method and system for inspecting polarization in a fibered optical path. The method being executed by a computer-implemented system comprising a controller and at least one detector communicatively coupled to the controller, the computer-implemented system being operatively connected to the fibered optical path, including: causing a laser to emit at least one optical pulse into the fibered optical path; detecting a plurality of reflected optical signals from the fibered optical path; determining a plurality of experimental correlation values based on the plurality of reflected optical signals and a reference signal function; and in response to a given experimental correlation value of the plurality of experimental correlation values being less than a threshold, identifying a mechanical disturbance caused by birefringence in the fibered optical path, the mechanical disturbance being located at a location of the plurality of locations corresponding to the given experimental correlation value.

An optical fiber (10) for measuring pressure includes a core (12) for guiding an optical signal along a length of the core (12) and a cladding (14) including a plurality of stress-applying members (16) disposed about the core (12). The plurality of stress-applying members (16) are disposed symmetrically about the core (12) and parallel to the core (12) to induce enhanced symmetric shear stress upon application of an external pressure while preventing birefringence. The optical fiber (10) provides improved strain sensitivity compared to standard single-mode optical fibers.

The invention discloses a polarization-maintaining hollow-core anti-resonance optical fiber with an arc-shaped cladding. The polarization-maintaining hollow-core anti-resonance optical fiber comprises a fiber core region and a cladding region, the fiber core area is formed by surrounding of the cladding area and is in a long strip shape. The cladding area comprises a cladding tube, a half-tube structure and an outermost sleeve; the cladding tube comprises two nested circular tubes; the two nested circular pipes are tangent to each other, and the outer circular pipe is in contact with the outermost sleeve; the whole optical fiber structure meets central symmetry. The hollow-core anti-resonance optical fiber has the unique advantages of low loss, low nonlinearity, high temperature stability and the like, and optical signals can be well limited in the fiber core for transmission. The effective mode refractive index of the polarization state is modulated through the y-pol reverse cross coupling of the quartz wall of the half-tube structure to the fundamental mode, and meanwhile the fundamental mode of the air fiber core is effectively limited through the nested tube in the cladding area, so that the low-loss performance is considered while high birefringence is achieved. And support is provided for application in the fields of signal transmission, precision sensing, optical fiber gyroscopes and the like.

The invention relates to the technical field of optical fiber communication, in particular to a crescent-shaped asymmetric polarization-maintaining hollow-core anti-resonance optical fiber, which comprises a cladding region, a polarization-maintaining layer and a polarization-maintaining layer, the crescent-shaped anti-resonance unit and the circular anti-resonance unit are located on the slow axis of the optical fiber, the inferior arc-shaped anti-resonance unit and the major arc-shaped anti-resonance unit are symmetric about the x axis, and the shapes of all the anti-resonance units are different from each other; the fiber core area is an air fiber core area defined by the outermost cladding tube and the adjacent cladding tube of the crescent-shaped anti-resonance unit. At least one of the anti-resonance units is provided with a multi-layer nested structure, and the multi-layer nested structure comprises nested cladding tubes or circular rings; the circular cladding tube is fixed with the outer supporting tube in an internally tangent manner, the fan-shaped cladding tube is connected with the outer supporting tube, the embedded structure in the circular cladding tube is fixed with the corresponding cladding tube in an internally tangent manner, and the thickness of the cladding tube adjacent to the fiber core area in the crescent anti-resonance unit is greater than that of the other cladding tubes. According to the invention, low-loss transmission and high birefringence can be realized.

The present invention concerns a system for generating quantum keys between two nodes of an optical communication network. The system comprises a transmitting node and a receiving node, operationally connected to each other by at least one birefringent optical communication channel. The transmitting node comprises a photon source, an optical port adapted to transmit and receive photons on the optical communication channel, a detector assembly adapted to detect and count photons received from the receiving node. The receiving node comprises an optical port for receiving and transmitting photons on the optical communication channel, and a photon emitter adapted to emit at least one photon in response to the at least one photon transmitted by the transmitting node. The photon emitter comprises at least one birefringent element. Advantageously, the receiving node comprises control means of the photon emitter. The control means are adapted to adjust a birefringence of the at least one birefringent element as a function of polarization information associated with the at least one photon transmitted by the transmitting node. In particular, the polarization information is extracted from the at least one photon transmitted by the transmitting node or is provided by the transmitting node. Advantageously, the photon emitter comprises an emulator device of a Faraday rotator mirror or comprises a retroreflector consisting of three mirrors orthogonal to each other and rotated by 45° around respective orthogonal axes. The Faraday rotator mirror and the retroreflector are orientable in space to reflect the at least one photon transmitted by the transmitting node uniquely and determined when oriented appropriately.

The invention belongs to the technical field of optical fiber sensing, and discloses a distributed single detection method and device for group birefringence and phase birefringence of an optical fiber, which is based on clear distinguishing and complete modeling of physical mechanisms of phase birefringence and group birefringence. Noise and various interferences are effectively suppressed, so that the accuracy and reliability of parameter measurement are remarkably improved. Through efficient cross-correlation operation in an optical frequency domain and a distance domain, two types of birefringence distribution information are synchronously obtained in single measurement, the data processing and feature extraction efficiency is greatly improved, and the method is particularly suitable for high-resolution and long-distance distributed sensing analysis. The theoretical model and the solving method provided by the invention have universal applicability, so that the robustness and the stability of the system in different application environments are improved.

System and method for determining distributed birefringence variations in a polarization-maintaining optical fiber (PM fiber). The method includes causing a pump signal to be sent into the PM fiber to generate a Brillouin dynamic grating (BDG) therein, causing a first chirped probe optical pulse to be sent into the PM fiber, receiving a first reflected signal, the first reflected signal being a first portion of the first chirped probe optical pulse reflected by the BDG, receiving a second reflected signal, the second reflected signal being a second portion of the first chirped probe optical pulse reflected by the BDG, and determining a variation of birefringence of the PM fiber indicative of a variation of physical disturbance of the PM fiber between times of reflections on the BDG of the first and second reflected signals.

Method for laser material processing using a processing laser beam (3), wherein a first laser beam (8a), which is coupled into at least a first fiber core (9a) of an optical multicore fiber (9), and a second laser beam (8b), which is coupled into at least a second fiber core (9b) of the multicore fiber (9), are generated from a polarized input laser beam (5) using a birefringent crystal (7), wherein by influencing the polarization of the input laser beam (5) the ratio in which the power of the input laser beam (5) is divided between the first and the second laser beam (8a, 8b) is changed with a modulation frequency (f) between 1 Hz and 100 kHz, in particular between 100 Hz and 100 kHz, and thereby the first and the second laser beam (8a, 8b) can be coupled out of the multi-core fiber (9) alone or together as a processing laser beam (3). characterized by that the polarization is influenced by switching between linearly, circularly or elliptically polarized polarization by means of an electro-optic polarization modulator (6), in particular a Pockels cell or Faraday rotator, which can be controlled with the modulation frequency (f) to change the polarization of the input laser beam (5).

The invention relates to a high-birefringence multi-core elliptical polarization-maintaining optical fiber and a preparation method thereof, the high-birefringence multi-core elliptical polarization-maintaining optical fiber comprises a common cladding and at least three stress areas and polarization-maintaining core areas which are distributed in the common cladding, the stress areas are uniformly distributed along the circumferential direction at equal intervals, and the center connecting lines of the adjacent stress areas form a regular polygon. One elliptical polarization-maintaining core is arranged at the middle point of each side of the regular polygon, the long axis of each elliptical polarization-maintaining core is flush with each corresponding side of the regular polygon, and each elliptical polarization-maintaining core and two adjacent stress areas are configured to form a polarization-maintaining core area. According to the invention, by designing the plurality of elliptical fiber cores and adding the stress rods, more transmission channels are provided, the birefringence performance is stronger, and the process requirement of manufacturing is reduced. The arrangement of the shared stress area forms multiple independent channels, the structure is compact, crosstalk is small, higher density and larger capacity of the multi-core polarization maintaining optical fiber are achieved, and the multi-core polarization maintaining optical fiber has wide application prospects in the aspect of miniaturization of optical fiber gyroscopes and devices.

The application relates to the field of high-speed optical communication devices, in particular to a high-bandwidth double-slow-wave-electrode thin-film lithium tantalate electro-optic modulator. The lithium tantalate electro-optic modulator comprises, from bottom to top, a substrate layer, a bonding layer, a thin-film lithium tantalate layer, a cladding layer and an electrode layer. The electrode layer comprises a signal electrode, a first ground electrode, a second ground electrode and a plurality of periodically arranged double-slow-wave-electrode structures combined by sawtooth and T-shaped structures. The application solves the problem that the thin-film lithium niobate modulator is difficult to realize stable work in high-speed and high-power applications due to the inherent strong birefringence and photorefractive effect of the material, realizes the speed matching between the radio frequency signal and the optical carrier, solves the speed mismatching problem in the electro-optic modulator, and improves the electro-optic bandwidth of the modulator.

This invention relates to the field of image recognition technology, specifically a method for identifying transparent foreign fibers in cotton using polarization detection combined with image processing. The method includes the following steps: acquiring images using a polarization sensor and extracting temporal and angular information; calculating pixel phase delay; performing frequency domain analysis to determine the principal direction and generating a birefringence response; screening skeleton points based on grayscale and constructing fiber paths; combining phase gradients for extreme value analysis and intensity reconstruction to obtain global coordinates; and then weighted filtering based on directional differences to eliminate redundancy and obtain fiber position coordinates. In this invention, by combining image acquisition and feature expression paths, polarization response and texture information are fused to form multi-dimensional discriminative features, reducing noise and uneven illumination interference. Combining fiber continuity and optical response analysis enhances the ability to identify weak responses, making boundaries clearer and more stable. Furthermore, redundant points are compressed under directional classification and spatial constraints, improving positioning consistency and recognition accuracy, and achieving stable identification of transparent foreign fibers in complex scenarios.