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309 results about "Refractive index profile" patented technology

A refractive index profile is the distribution of refractive indices of materials within an optical fiber. Some optical fiber has a step-index profile, in which the core has one uniformly-distributed index and the cladding has a lower uniformly-distributed index. Other optical fiber has a graded-index profile, in which the refractive index varies gradually as a function of radial distance from the fiber center. Graded-index profiles include power-law index profiles and parabolic index profiles.

Naked eye 3D display optimization method based on real-time eyeball tracking

The invention discloses a naked-eye 3D display optimization method based on real-time eyeball tracking, and particularly relates to the technical field of naked-eye 3D display, and the method comprises the steps: capturing eyeball movement data in real time through a visual angle tracking sensor, and collecting illumination information in combination with an ambient light sensor; depth perception parameters are calculated based on pupil diameter variation and frequency, and a time sequence prediction type dynamic compensation coefficient is generated in combination with eyeball movement acceleration; acquiring an initial fixation point coordinate by using an improved spherical projection mapping model, and performing compensation coefficient correction to obtain a real-time coordinate; and finally, according to the real-time coordinates, dynamically adjusting the refractive index distribution of the nanostructure layer, the rotation angle of the polarizer, the focal length of the optical lens and other optical modulation parameters. The real-time distance is calculated through the binocular parallax algorithm, the depth mapping value is generated by combining the focal length of the camera and the baseline distance, the method can adapt to the illumination change and the user view angle, and the 3D display effect is optimized.
Owner:SHENZHEN EASYQUICK TECH CO LTD

Mach-Zehnder interferometer optical fiber sensor based on arc-shaped concave cavity single-mode optical fiber

The invention provides a Mach-Zehnder interferometer optical fiber sensor based on an arc-shaped concave cavity single-mode optical fiber. The device is characterized by comprising an incident optical fiber 1, a beam splitter 2, an interference arm 3, a beam combiner 4 and an emergent optical fiber 5 which are connected in sequence. The incident optical fiber 1 is used for transmitting an input optical signal, the beam splitter 2 couples the optical signal in the incident optical fiber 1 into the interference arm 3, the interference arm 3 is used as a transmission waveguide, three arc-shaped concave cavities with different depths and curvature radiuses are arranged in the interference arm 3, and when a solution to be detected is immersed in the concave cavities, the refractive index change modulates an interference spectrum through an optical path difference and a phase difference; according to the design of the three concave cavities, refractive index distribution of three independent positions in the reaction process can be measured at the same time, the beam combiner 4 recombines optical signals in the interference arm 3 and couples the optical signals into the emergent optical fiber 5, and the emergent optical fiber 5 is responsible for outputting the optical signals and transmitting the optical signals to detection equipment for analysis. According to the invention, multi-position synchronous detection is realized through the multi-cavity gradient sensitive characteristic and in combination with the femtosecond laser micromachining technology, the problem of accidental errors of a traditional single-position sensor is solved, and the sensor is suitable for scenes such as microfluidic reaction requiring dynamic monitoring of refractive index change.
Owner:GUILIN UNIV OF ELECTRONIC TECH

Wavelength-scanning-based lensless fourier ptychographic diffraction tomography microscopy method

The invention presents a lensless Fourier ptychographic diffraction tomography microscopy imaging method based on wavelength scanning. The technique uses only a wavelength-tunable light source for illumination on a lensless microscope experimental system to collect a series of coaxial holograms. Then, the three-dimensional scattering potential spectrum is filled using an iterative Fourier ptychographic method to restore the three-dimensional refractive index distribution of the sample directly. The present invention does not require complex modifications to traditional lensless on-chip microscopes. It can endow lensless on-chip microscopes with the ability of pixel super-resolution three-dimensional tomographic imaging.
Owner:NANJING UNIV OF SCI & TECH

Evaporation waveguide height determination method based on domestic numerical weather forecast mode

The invention relates to the technical field of aerospace meteorology, and particularly discloses a domestic numerical weather forecast mode-based evaporation waveguide height determination method, which comprises the following steps of: obtaining meteorological coupling data output by a domestic numerical weather forecast mode CMA-MESO; determining parameters according to the meteorological coupling data and a turbulent flux algorithm COARE; constructing a temperature vertical profile and a specific humidity vertical profile according to the parameters, the Monin-Obchhoff similarity theory and an NPS model; constructing a modified refractive index profile according to the temperature vertical profile and the specific humidity vertical profile; and determining the height of the evaporation waveguide according to the height corresponding to the lowest point of the corrected refractive index profile. The method is suitable for determining the evaporation waveguide height in a domestic business meteorological mode.
Owner:EARTH SYST NUMERICAL PREDICTION CENT OF CHINA METEOROLOGICAL ADMINISTRATION

Acoustic black hole lens based on three-dimensional radial gradient refractive index photonic crystal structure and design method

The invention relates to the technical field of acoustic functional devices, and discloses an acoustic black hole lens based on a three-dimensional radial gradient refractive index phonon crystal structure and a design method, a three-dimensional radial gradient refractive index distribution function n (r) with a center convergence characteristic is constructed, and incident sound waves are continuously guided and efficiently focused to the center of the lens in the propagation process; combining the feasibility constraint of an additive manufacturing process, designing a few-negative micro-lattice structure unit for realizing the gradient refractive index distribution, and determining key geometric parameters of the few-negative micro-lattice structure unit; according to the refractive index distribution function n (r), radially arranging the micro-lattice units in a three-dimensional space, and constructing an initial lens model; the sound field distribution, focusing performance and energy convergence efficiency of the model are verified and iteratively optimized in a mode of combining analytical modeling and finite element method simulation, and a three-dimensional radial gradient refractive index photonic crystal acoustic black hole lens design model with wide-angle incidence compatibility and broadband response capability is obtained.
Owner:NAT UNIV OF DEFENSE TECH

Distributed ground-based radar atmospheric refraction error calculation method for celestial body observation

PendingCN120802198AWave based measurement systemsICT adaptationEarth surfaceCelestial observation
The invention discloses a distributed ground-based radar atmospheric refraction error calculation method for celestial body observation. According to the method, a local numerical weather forecast model is corrected by using real-time surface meteorological parameters, atmospheric refractive index profile data containing elevation meteorological information is obtained, a geometric elevation angle of a celestial body target is taken as a standard, and a neutral atmospheric refractive index error is searched in combination with a corrected data source and a ray tracing method, so that the atmospheric refractive index is obtained. And finally, neutral atmospheric refraction error calculation and correction are realized. The effectiveness of the algorithm is verified through simulation.
Owner:BEIJING INST OF TECH

Vortex ultrasonic transducer, acousto-optic coaxial modulation method and analogue simulation method

The invention discloses a vortex ultrasonic transducer, an acousto-optic coaxial modulation method and an analogue simulation method, and relates to the technical field of acousto-optic modulation.The method comprises the steps that a focused vortex sound field is generated through the vortex ultrasonic transducer with a center perforated hole, sound beams and light beams are coaxially propagated in the same direction, the sound field is used for regulating and controlling medium refractive index distribution, and the sound field is used for generating a focused vortex sound field; and light beam focusing spiral propagation and scattering suppression are realized. A model is constructed through analogue simulation, and the regulation and control effect of the sound field on the light beams is analyzed. According to the invention, coaxial modulation of the vortex sound fields with different topological charges on the light beams is realized, and a new path is provided for research of an acousto-optic regulation and control technology.
Owner:XIDIAN UNIV

Offshore floating type low-altitude waveguide all-weather detection method and system

The invention discloses an offshore floating type low-altitude waveguide all-weather detection method and system, and relates to the technical field of marine environment monitoring and electronic information engineering.The method comprises the steps that the current weather condition is judged according to a rain intensity sensor, a miniature weather station, a visibility sensor and an infrared cloud measurement sensor; obtaining a temperature and humidity value range according to the current weather condition, and adding liquid water for correction according to the weather condition; a simulated brightness temperature is obtained according to a MonoRTM model by combining an air pressure profile constructed by sea surface air pressure and a pressure height formula; designing a multi-objective genetic inversion algorithm, constructing an objective function, and when the objective function obtains a minimum value, obtaining an inverted atmospheric parameter profile group; and according to the atmospheric parameter profile group, calculating an atmospheric refractive index profile, judging whether a low-altitude waveguide occurs or not, and uploading a result to a shore station data management center. According to the invention, the atmospheric absorption coefficient is corrected according to different weathers, and all-weather and high-precision monitoring of the low-altitude waveguide on the offshore floating platform is realized.
Owner:OCEANOGRAPHIC INSTR RES INST SHANDONG ACAD OF SCI

Inversion method for obtaining N2O gas volume mixing ratio profile based on short wave infrared laser occultation detection technology

The invention discloses an inversion method for obtaining an N2O gas volume mixing ratio profile based on a short-wave infrared laser occultation detection technology. The inversion method comprises the following steps: calculating a short-wave infrared atmospheric refractive index profile at the center position of an N2O gas absorption spectral line; calculating a collision parameter profile according to the short-wave infrared atmospheric refractive index profile, respectively calculating atmospheric transmittance profiles of an N2O gas absorption spectral line and a reference spectral line based on normalized energy data of infrared laser occultation detection, and executing Abel integral inverse transformation on a difference value between the atmospheric transmittance profiles to obtain an N2O gas absorption coefficient profile; converting the N2O gas absorption coefficient profile into an N2O gas initial volume mixing ratio profile; and by taking the N2O gas initial volume mixing ratio profile as an initial value, carrying out analog calculation on an atmospheric transmittance profile after N2O gas absorption, constructing a cost function, carrying out iterative optimization, outputting an N2O gas volume mixing ratio profile, and obtaining a final inversion result. According to the method, the inversion precision is improved.
Owner:INST OF ATMOSPHERIC PHYSICS CHINESE ACADEMY SCI

Optical diffraction tomography resolving method, device and equipment

The invention provides an optical diffraction tomography resolving method, device and equipment, and belongs to the technical field of optical diffraction tomography. The method comprises the following steps: acquiring an off-axis interference image of a target sample; preprocessing the off-axis interference image to obtain a target refractive index distribution diagram; and taking the target refractive index distribution diagram as input, carrying out iterative reconstruction on the refractive index distribution condition of the target sample through a preset algorithm until the difference between a theoretical scattered field calculated based on the refractive index distribution condition and an actual scattered field measured by an experiment meets a preset condition, and obtaining a resolving result diagram, the preset algorithm is generated by combining total variation regularization and a beam propagation method, and is realized by using a GPU (Graphics Processing Unit) under CUDA (Compute Unified Device Architecture). High-precision and high-efficiency recovery of the three-dimensional refractive index of a sample is realized, and the resolving efficiency and accuracy of optical diffraction tomography are improved.
Owner:CHENGGUAN OPTICAL TECHNOLOGY (NANTONG) CO LTD

Deep ultraviolet laser epitaxial structure and epitaxial growth method thereof

According to the deep ultraviolet laser epitaxial structure and the epitaxial growth method thereof provided by the invention, the Al component of the first waveguide layer is linearly and progressively increased from the side close to the electron injection layer to the side close to the quantum well active layer; or the Al component of the second waveguide layer is linearly and progressively decreased from the side close to the quantum well active layer to the side close to the hole injection layer to form refractive index distribution which takes the barrier layer of the quantum well active layer as the highest refractive index point and gradually decreases towards one side (the n-type side or the p-type side), so that the light field is firmly bound near the quantum well active layer, and the light limiting capability is remarkably enhanced; meanwhile, high-low Al components of the p-type side (the second waveguide layer) gradually change to generate a strong polarization electric field, ionization of a p-type doped acceptor (such as Mg) can be promoted, two-dimensional hole gas (2DHG) can be induced, and the hole concentration is improved; the low-high Al components of the n-type side (the first waveguide layer) are gradually changed, so that two-dimensional electron gas can be induced, and the electron concentration is improved.
Owner:WUHAN YOUWEIXIN TECH CO LTD

COB process circuit board manufacturing process for photoelectric display

PendingCN120435139ANanosecondDisplay device
The invention discloses a manufacturing process of a COB (Chip On Board) process circuit board for photoelectric display. The manufacturing process comprises the following steps: performing constant-amplitude direct-current driving on a light-emitting chip array before injection of packaging glue to obtain full-board light field baseline data; the refractive index distribution of the packaging adhesive is regulated and controlled through multi-phase current pulses after the packaging adhesive is injected; forming a composite structure of a high-refractive-index chip interconnection interface and a low-refractive-index packaging surface by using Joule heat in a packaging adhesive crosslinking stage; the metal surface roughness is adjusted through nanosecond cosine pulses so as to control the plasma resonance characteristic; and finally, carrying out fine adjustment on the local refractive index by utilizing the interaction of the moving ions and the polar side chain. According to the technical scheme, stable refractive index distribution can be formed in the chip packaging structure through multi-physics field coupling regulation and control, formation of sub-wavelength stray light waveguides is effectively restrained, the problems of dynamic color cast and brightness flicker in an ultra-small pixel pitch COB display device are solved, and the optical performance consistency of the device is improved.
Owner:JIAN MANKUN TECH

Over-the-horizon communication parameter dynamic adjustment method based on evaporation waveguide

The invention relates to the field of radio transmission, and discloses an evaporation waveguide-based beyond-visual-range communication parameter dynamic adjustment method, which comprises the following steps of: installing a meteorological sensor and a hydrological sensor at a specified height of an offshore launching platform, and obtaining meteorological and hydrological data at the specified height; calculating to obtain an evaporation waveguide height diagnostic value and an atmospheric correction refractive index profile by using the obtained meteorological and hydrological data; according to the obtained atmosphere correction refractive index profile, the lowest trapping frequency and the critical incident angle in the current environment are obtained through calculation; determining a communication frequency range and antenna parameter ranges of the transmitting end and the receiving end; and searching in a communication frequency range and an antenna parameter range by adopting a particle swarm optimization algorithm to obtain the communication frequency with the minimum propagation loss and the optimal antenna parameter configuration. According to the method disclosed by the invention, the optimal frequency capable of carrying out beyond visual range communication in the evaporation waveguide environment can be output in real time, and the antenna parameters of the system are dynamically adjusted through the antenna servo system according to the meteorological and hydrological environment.
Owner:OCEANOGRAPHIC INSTR RES INST SHANDONG ACAD OF SCI

Intraocular lens that improves overall vision where there is a local loss of retinal function

PendingUS20260144629A1RefractometersSkiascopesOptical propertyPeripheral retina
Systems and methods are provided for improving overall vision in patients suffering from a loss of vision in a portion of the retina (e.g., loss of central vision) by providing symmetric or asymmetric optic with aspheric surface which redirects and / or focuses light incident on the eye at oblique angles onto a peripheral retinal location. The intraocular lens can include a redirection element (e.g., a prism, a diffractive element, or an optical component with a decentered GRIN profile) configured to direct incident light along a deflected optical axis and to focus an image at a location on the peripheral retina. Optical properties of the intraocular lens can be configured to improve or reduce peripheral errors at the location on the peripheral retina. One or more surfaces of the intraocular lens can be a toric surface, a higher order aspheric surface, an aspheric Zernike surface or a Biconic Zernike surface to reduce optical errors in an image produced at a peripheral retinal location by light incident at oblique angles.
Owner:AMO GRONINGEN

In-situ harmful gas monitoring method for sewage treatment plant structure

The invention discloses an in-situ harmful gas monitoring method for sewage treatment plant structures, and particularly relates to the field of in-situ harmful gas monitoring, and the in-situ harmful gas monitoring method comprises the following steps: collecting refractive index disturbance data of a local gas-liquid-gas interface caused by bubble release in a sludge tank or an anaerobic tank, and forming a refractive index distribution field changing along with time; and modeling an infrared light propagation path based on the refractive index distribution field, executing infrared absorption inversion operation, solving a first concentration result of the harmful gas, and establishing a mapping relationship between the first concentration result and the refractive index distribution field. Through coupling calculation of a refractive index distribution field caused by bubble disturbance and an infrared absorption inversion process, a reciprocating iteration and time sequence prediction chain is constructed so as to correct dynamic optical distortion and stably solve the real release intensity of harmful gas.
Owner:NISHIHARA ENVIRONMENT ENG SHANGHAI CO LTD

Communication optimization method, device and system for optical fiber splitter

The invention discloses a communication optimization method, device and system for an optical fiber optical splitter, and belongs to the field of optical fiber optical splitter communication, and the method comprises the steps: optimizing the refractive index distribution of the optical fiber optical splitter and a connection end face structure, and obtaining an adjusted optical splitter; calculating a coupling coefficient between different modes according to the geometric parameters and the real-time signal parameters of the adjusted optical splitter; according to the method, the asymmetric refractive index distribution and the structure of the optical fiber port can be adjusted, and then the coupling coefficients of different modes of the adjusted optical fiber splitter are calculated; the optical fiber splitter is optimized according to the coupling coefficient and the real-time communication parameter of the optical fiber splitter, so that the coupling coefficients of different modes of the optical fiber splitter meet actual requirements, the influence of signal distortion and attenuation during coupling is reduced, and the signal precision is improved.
Owner:GUANGZHOU POWER SUPPLY BUREAU GUANGDONG POWER GRID CO LTD

Photocuring printing scattering suppression method and system based on acousto-optic modulation

The invention relates to the technical field of additive manufacturing, in particular to a photocuring printing scattering suppression method and system based on acousto-optic modulation. According to the method, in the photocuring printing process, an acousto-optic modulation device is used for generating a focused ultrasonic field in a printing material, specific refractive index distribution is formed in the material based on the photoelastic effect, and therefore a refractive index regulation and control area used for restraining and guiding scattered light propagation is constructed in a local space; therefore, the scattering effect is suppressed, and the forming precision and the structural fidelity are improved. The system comprises a photocuring device, a light source, a printing platform and an acousto-optic modulation device used for achieving the method, the acousto-optic modulation device is composed of an ultrasonic transducer and an acoustic lens, and the acousto-optic modulation device forms a focusing sound field under external excitation and works in cooperation with the light source. The method is suitable for photocuring printing of various high-scattering light-sensitive composite materials, comprises material systems containing particles, cells or components with remarkable refractive index difference, and has good material adaptability.
Owner:CENT SOUTH UNIV

Lens manufacturing method and system, progressive lens and repairing method

The invention provides a lens manufacturing method and system, a progressive lens and a repairing method. The repairing method comprises the following steps: coating photoresist on a lens substrate; and photoetching a preset micro-nano structure on the lens substrate through a photopolymerization reaction between laser emitted by a laser system and the photoresist to obtain the lens with the micro-nano structure in a preset layout mode, and realizing the required refractive index distribution of the lens through the micro-nano structure in the preset layout mode. The invention provides higher-precision processing capability, smoother refractive index transition and higher design and manufacturing flexibility, thereby meeting the requirements of the market for high-quality progressive lenses. The high-precision progressive lens manufacturing method provided by the invention is a solution provided aiming at the limitation of a traditional process, and aims to improve the optical performance of the progressive lens and the visual experience of a user.
Owner:南通诺瞳奕目医疗科技有限公司 +1

Temperature measurement device, temperature measurement method, and program

PCT designated stageWO2025258574A1Thermometers using physical/chemical changesContinuous measurementOptical coefficient
A temperature measurement device (1) comprises: a light emission unit (10) that generates coherent, continuous measurement-light; a light detection unit (30) that detects reflected light or transmitted light of the continuous measurement-light which is projected onto a sample (50) to be measured; and an analysis unit (42) that calculates a temperature distribution of the sample (50) to be measured on the basis of the intensity of the reflected light or the transmitted light detected by the light detection unit (30). The analysis unit (42) calculates the optical thickness of the sample (50) to be measured from a temporal change in the intensity of the reflected light or the transmitted light and, by using a refractive index distribution model representing the relationship between the optical thickness and a refractive index distribution in the thickness direction of the sample (50) to be measured at the time of a temperature change, calculates the refractive index distribution from the optical thickness, and calculates the temperature distribution of the sample (50) to be measured by converting the refractive index distribution into the temperature distribution on the basis of the thermo-optical coefficient of the sample (50) to be measured.
Owner:HIROSHIMA UNIVERSITY

High-speed silicon light engine method and device for silicon light module

The invention relates to the related technical field of silicon photon chips, in particular to a high-speed silicon optical engine method and device for a silicon optical module, and the method comprises the steps: obtaining basic technical parameters of an optical fiber connection product with the silicon optical module; the refractive index distribution and the waveguide section size of the silicon optical waveguide are configured, and a multi-mode waveguide array is constructed; an electro-optical modulator array is integrated in a multi-mode waveguide array, and the coupling efficiency of waveguides and optical fibers is adjusted in real time through dynamic impedance matching; meanwhile, the high-speed electric drive circuit is used for driving the electro-optical modulator array and optimizing rising edge characteristics / falling edge characteristics of signals, and power consumption adjustment is carried out on the high-speed electric drive circuit. The technical problem that the optical signal quality is reduced due to the fact that the silicon optical waveguide design mostly adopts fixed parameters and mode crosstalk is prone to occurring in a high-speed transmission scene is solved, and the technical effects that the waveguide refractive index is dynamically configured, the multi-mode waveguide array is constructed, the mode crosstalk is effectively reduced, the transmission loss is reduced, and the optical signal transmission quality is improved are achieved.
Owner:WUHAN YILUT TECH CO LTD

Broadband anti-bending multimode optical fiber and preparation method thereof

The invention relates to a broadband bending-resistant multimode optical fiber and a preparation method thereof, the refractive index profile of a core layer is in a gradually-changed parabola shape, the distribution index alpha is 1.95-2.65, the radius R1 of the core layer is 12-35 microns, the delta 1max is 0.9%-1.4%, the relative refractive index difference delta 1min at the R1 position of the edge of the core layer is-0.16%--0.06%, cladding layers comprise an inner cladding layer, a first sunken cladding layer, a second sunken cladding layer and an outer cladding layer from inside to outside in sequence, the inner cladding layer is sequentially provided with a first inner cladding layer and a second inner cladding layer from inside to outside, the single-side width (R4-R3) of the first sunken cladding layer is 1.5-9.0 [mu] m, delta 4 is-1.1%--0.60%, the single-side width (R5-R4) of the second sunken cladding layer is 1.0-3.0 [mu] m, delta 5 is-1.0%--0.55%, the radius R6 of the outer cladding layer is 60-65 [mu] m, and delta 6 is-0.12-0.12%. The core cladding is reasonable in structural design, has the excellent characteristics of high bandwidth, strong bending resistance and low attenuation, and is high in transmission efficiency and excellent in long-term stability and reliability.
Owner:YANGTZE OPTICAL FIBRE & CABLE CO LTD

Axial lens water-jet guided laser automatic coupling system

The utility model belongs to the technical field of water-jet guided laser, and relates to a shaft lens water-jet guided laser automatic coupling system, which comprises a laser, a beam expander, a wave plate, a detection light source, a focusing module, a light focusing plate, a control system and a sample piece, the emitted light of the laser is expanded and shaped into parallel light, then the parallel light is converted into a circularly polarized light beam state, the parallel light is turned to enter the gradient refraction lens, and the gradient variable refractive index distribution is gradually reduced along the radial direction, so that the light transmitted along the axial direction can be continuously refracted, and the emergent light can be smoothly and continuously converged to one point; by adopting the gradient refraction module and the adjustable reflecting mirror, the laser beam can be more effectively coupled into the beam column, the energy loss is reduced, and the laser water jet coupling efficiency of water-jet guided laser processing is effectively improved.
Owner:SHAANXI WOTE RADIUM CESIUM MASCH MFG CO LTD

Direct modulation distributed feedback semiconductor laser and preparation method thereof

The invention discloses a direct modulation distributed feedback semiconductor laser and a preparation method thereof. An epitaxial layer structure of the direct modulation distributed feedback semiconductor laser sequentially comprises a substrate, a buffer layer, a first limiting layer, an active layer, a second limiting layer, an upper cladding and a top contact layer from bottom to top, the epitaxial layer structure also comprises a variable period grating layer which changes periodically along the cavity length direction. The period of the variable-period grating layer corresponds to refractive index distribution in a laser cavity, the grating period corresponding to a region with a relatively large refractive index is relatively small, and the grating period corresponding to a region with a relatively small refractive index is relatively large; and the variable-period grating layer can realize chirp control of the output signal. The chirp effect formed by the material when the device is modulated is reduced or compensated through the chirp effect of the variable-period grating layer structure, so that the limitation of parasitic chirp of the device on the transmission performance is solved.
Owner:RIZHAO AI RUI OPTOELECTRONICS TECH CO LTD

Rainy day troposphere refractive index profile inversion method based on buoy platform

The invention discloses a rainy day troposphere refractive index profile inversion method based on a buoy platform, and relates to the technical field of marine atmosphere exploration, and the method comprises the steps: obtaining a priori knowledge base based on sounding data statistical learning, setting a threshold value, and searching and constructing an initial parameter profile in the priori knowledge base; decomposing the population into a plurality of sub-populations, distributing each sub-population to different CPU / GPU nodes, and calculating a target function for each individual; obtaining sea surface temperature and sea surface humidity from the buoy platform as boundary constraint conditions, performing inversion by using a multi-target genetic immune algorithm, and obtaining an inversion result when a target function value is less than or equal to a threshold value; and calculating an atmospheric refractive index profile based on an inversion result. According to the method, attitude shaking of the offshore floating platform is considered and corrected; the accuracy of inversion of the troposphere refractive index profile in rainy days is effectively improved, the offshore troposphere refractive index profile is detected in real time, and the calculation efficiency is effectively improved.
Owner:QILU UNIVERSITY OF TECHNOLOGY (SHANDONG ACADEMY OF SCIENCES)

Flow velocity measurement method and flow velocity measurement device

This flow velocity measurement method comprises: a heating step (S102) for heating a part of a medium; a first optical measurement step (S101) for acquiring a first image of observation illumination light that has passed through the medium, at a first timing; a second optical measurement step (S103) for acquiring a second image of observation illumination light that has passed through the medium, at a second timing which is after the first timing and which is during or after execution of the heating step; a first refractive index distribution change calculation step (S104) for calculating first information pertaining to a change in refractive index distribution based on the heat distribution of the medium on the basis of the first image and the second image; and a flow velocity calculation step (S105) for calculating the flow velocity of the medium on the basis of the first information pertaining to the change in the refractive index distribution.
Owner:KOWA CO LTD

Micro-nano grating and photocathode collaborative design method

The application discloses a micro-nano grating and photocathode collaborative design method. The method breaks the traditional isolated design, and considers the micro-nano grating and the photocathode as an organic whole, and takes the spectral response or integral quantum efficiency of the system as a whole as a target function. Specifically, the method comprises the following steps: establishing a system structure model and clearly defining an optimization target and process constraints; establishing a complex refractive index-wavelength correlation model of the photocathode to accurately obtain a complex refractive index distribution; determining a set of parameters to be optimized and setting initial values; calculating the system electric field distribution under the current parameters based on an electromagnetic simulation model; combining the electric field distribution and the photoelectric emission mechanism to calculate the spectral response of the system in the target waveband; and using a parameter optimization algorithm to iteratively search the parameter space, and outputting an optimal parameter combination. The application fully considers the electromagnetic and photoelectric coupling between the two and the actual process constraints, has the advantages of high design accuracy, strong pertinence, good implementability and the like, and can significantly improve the detection sensitivity of a weak light detection device.
Owner:NO 55 INST CHINA ELECTRONIC SCI & TECHNOLOGYGROUP CO LTD

Bend insensitive high bandwidth multimode optical fiber

The application discloses a bending-insensitive high-bandwidth multi-mode optical fiber, which comprises a core layer, an extension layer, an inner cladding layer, a sunken cladding layer and an outer cladding layer arranged in sequence from inside to outside, the refractive index profile of the core layer is parabolic, the distribution index is 1.9-2.2, the maximum relative refractive index difference of the core layer center position is 0.9%-1.2%, the relative refractive index difference of the extension layer is -0.03% to -0.02%, the difference between the highest relative refractive index difference and the lowest relative refractive index difference of the inner cladding layer is 0.005%-0.03%, the single-side radial width of the inner cladding layer is 0.5-4 mu m, the single-side radial width of the sunken cladding layer is 3-9 mu m, and the relative refractive index difference of the sunken cladding layer is -0.7% to -0.4%. In the application, the optical fiber viscosity is optimized, the sensitivity of the optical fiber bandwidth to wavelength is reduced, the optical fiber has good bending resistance and super high bandwidth performance by reasonably designing the waveguide structure and the doping system.
Owner:JIANGSU HENGTONG OPTICAL FIBER TECH +2

A wavelength locking system for a silicon oxide microring resonator

This invention discloses a wavelength locking system for a silicon oxide microring resonator, comprising a photoelectric conversion module, a feedback control module, a radio frequency drive module, an interdigital transducer, a zinc oxide film, a lock-in amplifier module, two analog-to-digital conversion modules, and a digital-to-analog conversion module. The radio frequency drive module generates an alternating electrical signal and applies it to the interdigital transducer, causing the zinc oxide film to vibrate mechanically and generate surface acoustic waves that propagate to the vicinity of the silicon oxide microring resonator, inducing mechanical stress and strain, changing the refractive index distribution of the silicon oxide microring resonator, and modulating the frequency, phase, and intensity of the internal optical signal. The feedback control module adjusts the thermal power of the microring heater based on the voltage signals output by the lock-in amplifier module and the photoelectric conversion module, thereby adjusting the resonant wavelength of the silicon oxide microring resonator and locking the wavelength of the optical signal output by the silicon oxide microring resonator to the target wavelength. The advantage is that it can accurately lock the wavelength of the silicon oxide microring resonator, resulting in a high wavelength locking effect.
Owner:ZHEJIANG UNIV

Optical Waveguide

Provided is an optical waveguide capable of suppressing optical loss in a groove portion into which a wavelength plate is inserted while eliminating polarization dependence. An optical waveguide according to the present disclosure is an embedded optical waveguide formed on a substrate, including a lower cladding; a core; an upper cladding; and a groove formed on one side of a side surface of the core with respect to a light propagation direction and extending in a direction parallel to the core, wherein a refractive index distribution in a plane perpendicular to the light propagation direction is a distribution in which a principal axis of a refractive index ellipse has a rotation amount with respect to a horizontal direction of the substrate.
Owner:NT T INC