32 results about "Polarization dependent" patented technology

The invention provides a metasurface structure and method for realizing transverse polarization focusing light splitting, and the metasurface structure comprises a substrate and a surface structure which is disposed on the substrate. The surface structure is composed of a plurality of sub-wavelength structure units which are arranged in a concentric circular ring mode. The sub-wavelength structure unit performs polarization-independent focusing of an incident beam through transmission phase regulation and control, and performs polarization-dependent light splitting of the incident beam through geometric phase regulation and control. The point diffraction plate can realize light beam splitting and focusing functions related to polarization, has the advantages of being simple in structure and high in integration level, solves the technical problems that an existing point diffraction plate does not support synchronous phase-shifting interference measurement and the contrast ratio of interference fringes is low, and enables the contrast ratio of the interference fringes of point diffraction interference measurement to be higher, the resolving precision to be higher and the resolving speed to be higher.

The invention discloses a parameter measuring device and method of an optical switch and optical communication equipment, and relates to the technical field of optical switch measurement, and the parameter measuring device of the optical switch comprises an optical path module, a signal conditioning circuit, a driving module, a signal acquisition module and an upper computer. The optical path module converts the optical signal into a current signal; the signal conditioning circuit conditions the signal into a voltage signal and amplifies the voltage signal; the driving module provides a driving signal and a synchronous triggering signal; the signal acquisition module acquires a voltage signal based on the trigger signal; the upper computer calculates performance parameters of the optical switch according to the voltage signals acquired for multiple times, wherein the performance parameters at least comprise two items of insertion loss, extinction ratio, switching time and the like; according to the technical scheme, one-key measurement of performance parameters such as insertion loss, extinction ratio, switching time, polarization-dependent loss, insertion-dependent loss and repeatability of the optical switch can be realized, meanwhile, the measurement cost of the optical switch is reduced, and the test efficiency and accuracy are improved.

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 application discloses a kind of parameter measuring device of optical switch and method, optical communication equipment, it is related to optical switch measurement technical field, the parameter measuring device of optical switch includes optical path module, signal conditioning circuit, drive module, signal acquisition module and host computer;Optical path module converts optical signal into current signal;Signal conditioning circuit is conditioned as voltage signal and amplifies;Drive module provides driving signal and synchronous trigger signal;Signal acquisition module is based on trigger signal and collects voltage signal;Host computer calculates the performance parameter of optical switch according to voltage signal collected multiple times, and performance parameter at least includes two items in insertion loss, extinction ratio, switching time etc.;The technical scheme of the application can realize the one-key type measurement of the performance parameter such as insertion loss, extinction ratio, switching time, polarization dependent loss, insertion dependent loss and repeatability of optical switch, while reducing the measurement cost of optical switch, improve test efficiency and accuracy.

The application provides a polarization-dependent reflective two-stage optical ring, which comprises a first collimator, a first beam splitting cube, a first optical rotation component, a second beam splitting cube, a third beam splitting cube of a second optical rotation component and a second collimator arranged along a first optical path, and three beam splitting cubes are respectively light splitting dielectric films; the application combines the characteristics of a transmission two-stage ring and a reflective ring, two optical rotation components are arranged on the first optical path from the first collimator to the second collimator, thereby realizing the series connection of two isolation systems, playing a double-stage isolation effect, meanwhile, the application realizes the optical path folding of a second optical path from the second collimator to the third collimator by using a reflective component, and optical components are multiplexed in one of the optical rotation components, thereby also achieving a double-stage isolation effect; while realizing the double-stage isolation effect, the application also reduces the product volume, is beneficial to the integration of equipment and is also beneficial to cost reduction.

An eyewear device includes a lightguide having a world-side surface and an eye-side surface, a display oriented to emit light toward the lightguide, and a beam steering element that includes a first polarization grating positioned along an optical path between the display. The first polarization grating diffracts light emitted by the display into orders having different polarizations and the orders are selectively conveyed into different eyeboxes. The eyewear device also includes a frame that supports the lightguide, the display, and the first polarization grating. In some cases, the different polarizations include a right circular polarization or a left circular polarization and the beam steering element includes a polarization dependent filter that filters right circularly polarized light in a first state and left circularly polarized light in a second state.

The disclosed systems and methods are for reducing polarization dependent loss in an optical link including: i) changing, by a state of polarization (SOP) controller, an SOP of an optical signal propagating in the optical link; ii) computing, by a link controller, a polarization dependent loss (PDL) in a portion of the optical link; iii) generating, by the link controller, a control signal according to the PDL; and iv) based on the control signal, changing, by the SOP controller, the SOP of the optical signal.

An optical property evaluation device 20 according to the present disclosure comprises: a test light generation unit 30 that generates test light; an input / output unit 40 that inputs the test light from one end of an optical fiber 10 under test in any polarization state, and acquires and outputs, from the one end, backscattered light from each point of the optical fiber 10 under test; a backscattered light complex electric field amplitude acquisition unit 50 that acquires, for each point of the optical fiber 10 under test, a complex electric field amplitude of the backscattered light output from the input / output unit 40; and an arithmetic processing unit 60 that converts the complex electric field amplitude into a matrix for each point of the optical fiber 10 under test, and evaluates polarization dependent loss using a singular value of the matrix.

A system and method for implementing a Variable Optical Attenuator (VOA) for high optical power handling. The VOA device may include an optical signal attenuation element with a fixed optical path to dump unwanted optical light to a light absorption material. The light absorption material may be thermally managed for reliability. The VOA device may support input light beams having any polarization state or composites of both P and S light. An embodiment of the present invention is directed to managing P light and S light through the VOA device to travel within a same optical path length to minimize Polarization Mode Dispersion (PMD). In addition, P and S polarization beams may be independently attenuated to minimizes Polarization Dependent Loss (PDL).

The invention relates to the technical field of optical communication devices, in particular to a multi-channel variable optical attenuator and a manufacturing method thereof, the multi-channel variable optical attenuator comprises a multi-channel variable optical attenuator photoelectric structure, and each variable optical attenuator photoelectric structure comprises an optical path structure and a heating circuit; wherein the optical path structure comprises an upper modulation optical waveguide and a lower modulation optical waveguide; one side of the upper modulation optical waveguide and one side of the lower modulation optical waveguide are jointly connected with an input bent optical waveguide, and the other side of the upper modulation optical waveguide and the other side of the lower modulation optical waveguide are jointly connected with an output bent optical waveguide. The heating circuit is arranged on the light path structure and comprises a heating electrode and electrode leads arranged at the two ends of the heating electrode. According to the invention, the optical crosstalk generated by stray light formed by light leakage at the input end to adjacent channels can be reduced, so that the performance of the device can be improved, such as polarization dependent loss and optical crosstalk reduction.

The invention discloses a digital domain distributed polarization dependent loss (PDL) measurement method in an optical network. The method comprises the following steps: obtaining an output optical signal of a section of link based on the polarization state (SOP) of an input optical signal of the section of link and the polarization dependent loss of the section of link; scanning the SOP to obtain a plurality of scanning polarization states, and respectively applying the obtained scanning polarization states to the input optical signal of the section of link; calculating a power side write value of the optical signal obtained after the scanning polarization state is applied each time by using a longitudinal power monitoring (LPM) technology based on a related method; calculating a polarization-dependent loss value, a corresponding azimuth angle and a phase angle of the section of link; calculating the SOP of the input optical signal of the section of link; and repeating the steps to measure the polarization dependent loss of the section of link until the polarization dependent loss is transmitted to the front of the receiving end. According to the invention, high-precision and high-stability monitoring of the distributed PDL is successfully realized, fitting of a large amount of data is not needed, and the method has the advantages of flexibility, real-time performance and low cost.

A bioreactor monitoring device and method configured for in-situ or ex-situ analysis is provided. The monitoring system (5) includes a tunable laser spectrometer (8) that generates a swept wavelength signal and transmits it through an optical fiber (110), a reference light detection means (158) that detects the swept wavelength signal after transmission from the tunable laser spectrometer (8) through the optical fiber (110), and a sample light detection means (132) that detects the swept wavelength signal after transmission through a sample detection region (12). The polarization means (152) and the reference light detection means (158) that detects the swept wavelength signal before transmission through the sample detection region (12) from the tunable laser spectrometer (8) through the optical fiber (110) address noise resulting from polarization dependent loss.

The utility model relates to the technical field of circulator bodies, in particular to a device for improving crosstalk of a polarization dependent circulator, which comprises a circulator body, the outer side of the circulator body is connected with three ports which are respectively a port I, a port II and a port III, an inner cavity is formed in the circulator body, the inner cavity is polygonal, and the outer side of the circulator body is connected with the port II. A first polarization beam splitter, a Faraday rotation piece, a half-wave plate and a second polarization beam splitter are sequentially arranged in the inner cavity in the direction from the first port to the second port, and an inclined face is arranged on the side wall in the inner cavity. According to the device for improving crosstalk of the polarization dependent circulator, the black coating opposite to the second polarization beam splitter and the first polarization beam splitter is arranged at the inclined plane in the inner cavity, so that fast-axis optical signal interference of an input signal can be effectively inhibited, and fast-axis light from the second polarization beam splitter can be prevented from returning to a port III again; by suppressing and isolating unnecessary optical signals, mutual interference between ports can be reduced, and the stability and reliability of the whole optical system can be improved.

The invention discloses a polarization dependent loss test method based on extruded optical fibers. The method comprises the following steps: connecting a polarization dependent loss test optical path of a to-be-tested piece; roughly searching an extreme point in a polarization state in a large-step manner; an extreme point is accurately found through curve fitting; and substituting an accurate extreme point searched by curve fitting into a formula to calculate a polarization dependent loss value. The invention provides a polarization dependent loss test method based on an extruded fiber, and the method comprises the steps: employing an extreme value searching and local fitting mode, and carrying out the testing of the polarization dependent loss; firstly, the approximate extreme point of the power curve corresponding to the polarization state is found, then the power point is selected near the extreme point for curve fitting, and the accurate extreme point is found through the fitted curve, so that the measurement accuracy is greatly improved, and the measurement speed of the polarization dependent loss is improved.

The utility model provides a double-ridge-shaped end face coupler based on a thick silicon platform. The double-ridge-shaped end face coupler comprises a substrate and a coupling waveguide structure. The substrate comprises a bottom silicon layer and a buried oxide layer, and a coupling waveguide structure is arranged on the buried oxide layer; the coupling waveguide structure comprises a double-ridge-shaped inverted-cone waveguide and a strip-shaped waveguide which are connected with each other. By adopting the thick silicon platform, the polarization dependent loss can be reduced; by adopting the double-ridge inverted-cone waveguide, the unification of low loss and high tolerance can be obtained; in addition, the coupler can be processed based on an SOI wafer, the device is of a single-layer silicon design, additional multi-layer manufacturing is not needed, the photoetching and etching cost can be saved, the process is simple, and the coupler is good in compatibility with a CMOS (Complementary Metal-Oxide-Semiconductor Transistor) platform.

Systems, apparatuses, and methods for an electronic display are disclosed. More specifically, the invention and disclosure relates to an electronic display that has a diffuse, paper-like reflectance characteristic for visible light, while being retroreflective and non-diffuse for infrared light, for easy image detection and analysis with infrared cameras, while preserving viewing properties of an electronic paper display for humans.

The application provides a kind of to realize transverse polarization focusing spectrometer super surface structure and method, including substrate, also include surface structure, the surface structure is arranged on the substrate;The surface structure is composed of multiple concentric ring arrangement subwavelength structure unit;The subwavelength structure unit carries out polarization independent focusing of incident light beam by transmission phase control, and the subwavelength structure unit carries out polarization dependent spectrometer of incident light beam by geometric phase control.The application can realize polarization dependent beam spectrometer and focusing function, with the advantages of simple structure, high integration, solve the technical problems that present point diffraction plate does not support simultaneous phase shift interferometry and interference fringe contrast is low, make the interference fringe contrast of point diffraction interferometry higher, higher, higher, faster.

Provided is a compact optical amplifier in which the polarization dependent gain of an SOA can be eliminated and the number of optical components is small. Specifically, provided is an SOA-integrated optical amplifier circuit (200) comprising a planar lightwave circuit (201) and a plurality of semiconductor amplifiers (SOAs) (203, 205) integrated on the same substrate, the SOA-integrated optical amplification circuit (200) characterized by comprising a plurality of SOAs (203, 205) that amplify light, a polarization separation unit (207) that separates incident light into independent first light in a first mode and second light in a second mode, a first polarization rotation unit (203a) that converts the first mode of first light separated by the polarization separation unit (207) to the second mode, a second polarization rotation unit (203b) that converts the second mode of the first light amplified by the first SOA (203) to the first mode, and a polarization multiplexing unit (209) that multiplexes the amplified light.

An optical device for polarization dependent loss compensation and a polarization controlling wavelength selective switch (PC-WSS). The device includes a polarization independent liquid crystal on silicon (PI-LCoS) structure, a first liquid crystal structure disposed on the PI-LCOS structure; and a second liquid crystal structure disposed on the first liquid crystal layer, the two liquid crystal structures having a common ground electrode. The PI-LCOS structure includes a metamaterial quarter-wave plate (QWP) disposed over a silicon substrate. The PC-WSS includes an optical assembly arranged to receive light from a fiber array unit; a polarization-insensitive grating structure optically aligned with the optical assembly; and the optical device for polarization dependent loss compensation optically aligned with the polarization-insensitive grating structure.

The invention discloses a visible light communication method and an underwater cleaning system. The method comprises the following steps: inserting a multi-orthogonal polarization pilot frequency in a frame starting region and adaptively setting pilot frequency energy according to the power of a previous frame; synchronously sampling the current of each light receiving surface, and obtaining a Stokes vector according to pilot frequency separation and normalization; calculating polarization dependent loss of each surface, weighting to obtain global loss, and comparing the depolarization degree with a statistical threshold to generate a compensation parameter; adjusting the polarization mapping of the uplink and verification channels according to the compensation parameters and redistributing the transmitting power; and carrying out trend prediction on global loss, sending out local heating and chemical cleaning instructions when maintenance conditions are met, and recording loss and configuration. According to the technical scheme, the polarization loss can be inhibited in the running process of the chlorine-containing swimming pool, the link symmetry is kept, and the continuous working time of the robot is prolonged.

The application provides a polarization-dependent device and an optical fiber laser, wherein self-made polyester transparent adhesive is used as a transmission tool, tantalum palladium sulfide is accurately placed in the center of the end face of an optical fiber jumper under a microscope, and the tantalum palladium sulfide is connected with another optical fiber jumper by using an optical fiber sleeve to form the polarization-dependent device. The tantalum palladium sulfide has excellent nonlinear polarization optical response, under the condition that the input pump power is constant, the polarization-dependent device based on the tantalum palladium sulfide can realize stable soliton and noise-like dual-mode controllable switching in a single superfast optical fiber laser. In a single superfast optical fiber laser system, the controllable stable switching of different superfast laser pulse modes has great expansion application potential. The polarization-dependent device based on the tantalum palladium sulfide in the application has simple structure, simple preparation and low cost, and has good nonlinear optical performance and long-term working stability.

The application provides a phase-sensitive optical time domain reflectometer, which comprises a polarization diversity receiving module, an amplification circuit and a signal acquisition and processing unit; a controller of the polarization diversity receiving module can adjust a first transimpedance amplifier, a second transimpedance amplifier and a gain multiple of the amplification circuit according to first photodetector information and the like sent by the signal acquisition and processing unit, so that the total gain of X-state electric polarization signals and Y-state electric polarization signals output by the amplification circuit is consistent, the problem of original output power imbalance is overcome from the perspective of ensuring responsivity and amplification multiple, then a polarization compensation coefficient is generated according to a preset rule to compensate for power imbalance caused by the polarization diversity receiving module manufacturing process. The application further discloses a method for eliminating polarization-dependent loss.

A method includes separating, by a polarization splitter rotator, an input light signal into a first light signal having a first insertion loss and a second light signal having a second insertion loss that is different than the first insertion loss; and attenuating, by an optical attenuator, the first light signal or the second light signal in order to compensate for a polarization dependent loss between the first light signal and the second light signal such that a total optical power of the first light signal and the second light signal is independent of a polarization state of the input light signal.

A near-eye display system is provided, comprising a light source configured to emit unpolarized light constituting a collimated image; a lightguide optical element configured to expand the optical aperture of a collimated image injected therein; and an optical device for receiving the collimated image prior to expansion by the lightguide optical element, and for increasing its polarity. The optical device comprises a substantially transparent substrate and a plurality of optical polarization elements, defining a polarization dependent optical multipath through the substrate between input and output interfaces thereof. The multipath comprises a rotating optical path configured to transmit and to cause a net rotation of the polarization of a first polarized component of input light, and a non-rotating optical path configured to transmit a second polarized component of the input light, having a polarization opposite that of the first polarized component, without causing a net rotation of its polarization.

Methods, devices and systems are described to eliminate or reduce unwanted polarization aberrations associated with interference filters. An example method for producing a polarization aberration compensator for a thin film interference filter includes obtaining a set of Mueller matrix values based on polarization measurements of the thin film interference filter over a spectral range, and generating a metric based on a difference between a compensated Mueller matrix and an identity matrix over the spectral range. The compensated matrix represents a cumulative Mueller matrix for a combination of the thin film interference filter and the polarization aberration compensator. A configuration of the polarization aberration compensator is determined based on evaluating the metric that eliminates or reduces the difference between the compensated Mueller matrix and the identity matrix over the spectral range. Configuration parameters, including thicknesses of birefringent layers, fast-axis angles and the number of birefringent layers in the compensator are obtained.

The invention discloses a dynamic polarization lock based on a multi-step simulated annealing algorithm, and belongs to the technical field of quantum communication and optical fiber communication. Aiming at the problem of polarization state drift caused by the influence of an external complex environment, the birefringence effect of an optical fiber, polarization mode dispersion and polarization dependent loss, energy of single pulse light is converted into peak voltage of output electric pulse in real time by utilizing an integral type optical signal detector based on a charge amplifier; and real-time measurement of the energy of a single optical pulse signal is realized. And a multi-step simulated annealing algorithm is rapidly operated by using the FPGA to search a target polarization state, so that high-speed polarization locking under the condition of pulsed light is realized. An extrusion type electric control polarization controller is utilized, piezoelectric ceramics are driven by applied voltage to extrude an optical fiber to change corresponding delay amount, and polarization state output of any target is controlled. The polarization state drift caused by the influence of an external complex environment, the birefringence effect of the optical fiber, polarization mode dispersion and polarization-dependent loss is effectively solved.

The application provides a polarization-related loss relieving method and system based on subcarrier polarization state control, comprising the following steps: S1, initializing a binary bit sequence to obtain a subcarrier polarization state parameter; S2, according to the subcarrier polarization state parameter, different polarization states are given to different subcarriers, and the system factor performance index is obtained through channel transmission; S3, the subcarrier polarization state parameter is iteratively optimized through a genetic algorithm, and the polarization-related loss effect is relieved through the optimization result. The application optimizes the subcarrier polarization state parameter based on the Q factor performance index of an optical communication system through a genetic algorithm, so that the polarization-related loss effect of the optical communication system is relieved and the system performance is optimized.

The invention belongs to the technical field of integrated optics, and discloses a polarization insensitive end face coupling device based on a silicon waveguide and a preparation method, and the polarization insensitive end face coupling device comprises a substrate layer, a lower cladding, a silicon waveguide layer and an upper cladding along a third direction; wherein the silicon waveguide layer sequentially comprises a mode field adiabatic evolution section, a first mode conversion section, a second adiabatic evolution section, a third adiabatic evolution section, a fourth mode conversion section and a convergence section along a first direction. The waveguide segments are deposited on the lower cladding and are connected with each other. According to the invention, the coupling loss is reduced, and low-loss transmission between the silicon waveguides with different thicknesses is realized; low polarization dependent loss is realized through mode field conversion; when the material of the silicon waveguide layer is deposited silicon, a bottom layer device can be effectively protected from being damaged as a back-end process; and potential simplification, expansion and optimization schemes can be provided for other devices.

The invention belongs to the technical field of spectral imaging and polarization optics, provides a polarization chromatic aberration compensation method for polarization multiplexing type acousto-optic tuned filtering (AOTF) spectral imaging, and designs a polarization chromatic aberration compensation module comprising a liquid crystal polarization grating according to the polarization dependence characteristic of an acousto-optic tuned filtering device. And chromatic aberration compensation of polarization multiplexing acousto-optic tuning is realized by matching the period of the liquid crystal polarization grating. Non-biased incident light enters an acousto-optic tuned filter through a front light path to generate two beams of polarization-state orthogonal narrow-band diffraction light, and the two beams of polarization-state orthogonal narrow-band diffraction light are collimated by a rear light path and screened by a shielding diaphragm, and then enter a liquid crystal polarization compensation module consisting of a liquid crystal wave plate and a liquid crystal polarization grating to be corrected; and finally, the image is focused to the detector through the imaging module to realize combined imaging. The method does not need mechanical movement or electric control adjustment, the structure is light and thin, and integration is easy.

We provide a general two dimensional grating coupler system that maximizes its coupling power, while simultaneously minimizing the polarization dependent loss ( PDL) for any linearly polarized input. This approach solves the long lasting problem of complete polarization insensitive fiber to chip grating coupler designs, using a passive device with no active control. In other embodiments, an arbitrary elliptical input state of polarization is dealt with using a passive scattering structure having two waveguide outputs into which the input free space beam is split according to its polarization components. A simple active control scheme is then used to combine these two waveguide outputs in phase to provide a single output with minimal PDL for arbitrary input state of polarization.