18 results about "Polarization dependent" patented technology

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.

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.

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.

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.

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 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 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 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 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.

An Er: YAG composite optical fiber laser based on nonlinear polarization rotation mode locking comprises a pumping source and an optical fiber annular resonant cavity, and the optical fiber annular resonant cavity is formed by connecting a wavelength division multiplexer, an Er: YAG composite optical fiber, an extrusion type polarization controller, a polarization dependent optical fiber isolator, a three-ring rotation type polarization controller and an optical fiber coupler through single-mode optical fibers. The pumping source is connected with the pumping end of the wavelength division multiplexer, and stable mode-locked laser pulses are output through 20% of the output end of the optical fiber coupler; or the optical fiber annular resonant cavity is formed by sequentially connecting a wavelength division multiplexer, an Er: YAG composite optical fiber, an optical fiber coupler, an extrusion type polarization controller, an optical fiber polarizer, a three-ring rotary type polarization controller and a polarization independent optical fiber isolator through optical fibers; an extrusion type polarization controller, an optical fiber polarizer and a three-ring rotary type polarization controller jointly achieve an artificial saturable absorber equivalent to nonlinear polarization rotation, and passive mode locking is achieved. The antenna has the advantages of ultra-wide gain spectrum, strong anti-interference capability and the like.