232 results about "Refractive index profile" patented technology

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.

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.

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.

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.

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.

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.

Disclosed are a method, a device, and an information processing program for determining, by using refractive index distribution data pertaining to an object to be observed, the region of a cell that has undergone programmed cell death in the object to be observed.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

The present invention discloses a semiconductor laser element, which comprises, from bottom to top, a substrate, a lower confinement layer, a lower waveguide layer, an active layer, an upper waveguide layer, and an upper confinement layer. A dark exciton resonance layer is provided between the lower confinement layer and the lower waveguide layer. The dark exciton resonance layer comprises a first dark exciton resonance layer, a second dark exciton resonance layer, and a third dark exciton resonance layer. The specific electron effective mass distribution and refractive index distribution of the dark exciton resonance layer of the present invention enhance the strong coupling effect between dark excitons and photons, reduce the effective mass of exciton polaritons and increase the group velocity, enhance the dipole resonance intensity and the nonlinear effect of exciton polaritons, enhance the coherence of dark exciton polaritons, reduce the laser mode number, increase the photon degeneracy, improve the output laser coherence, and improve the beam quality factor.

In order to provide a display device with variable viewing modes and that can be manufactured inexpensively with less technical cost, it is proposed in a display device (100) that a control unit (16) is designed to cause dynamic changes in the radiation characteristics of the display device (100) by manipulating liquid crystal optical units (12, 12a, 12b). The display device includes a backlight unit (10), a liquid crystal display panel (11), at least one liquid crystal optical unit (12, 12a, 12b) and a control unit (16), wherein the liquid crystal optical unit (12, 12a, 12b) includes liquid crystal (13) that changes its refractive index profile according to an applied voltage (22).

Methods and devices relating to volumetric meta-optic structures. A method involves computationally designing a three-dimensional refractive index profile using an adjoint-based optimization process. The process optimizes for sorting light based on wavelength or polarization at specific oblique incidence angles and accounts for source divergence using Gaussian beam simulations. A mode overlap figure of merit is employed, optionally including terms to minimize crosstalk. Fabrication constraints like material binarization and minimum feature size are handled via differentiable filters. Physical crosstalk barriers may optionally be modeled during optimization. The resulting optimized profile defines a manufacturable multi-layer structure comprising patterned dielectric materials configured to perform the target sorting function efficiently under the specified oblique angle conditions. An array of such devices, potentially comprising structurally distinct elements optimized for different angles, can be integrated with an image sensor.

A method for fabricating a nonlinear optical waveguide with gradient refractive index distribution, in which a nonlinear optical crystal is prepared; a type of first heavy ions, a type of second heavy ions and parameters related to an irradiation process are determined; the first heavy ions are accelerated to generate a first ion beam; the nonlinear optical crystal is bombarded with the first ion beam to obtain a primary processed crystal; the second heavy ions are accelerated to generate a second ion beam; the primary processed crystal is bombarded with the second ion beam to obtain a secondary processed crystal; and the secondary processed crystal is segmented to obtain the desired optical waveguide.

The utility model relates to the field of optical fiber interference sensors, and discloses an M-Z interference sensor with a small excitation group velocity dispersion difference mode structure. Comprising a light injection single-mode optical fiber, a small-core-diameter step multimode optical fiber, a wide annular core optical fiber, an annular core optical fiber, a gradient refractive index multimode optical fiber, a large-core-diameter step multimode optical fiber and a light receiving single-mode optical fiber which are connected in sequence. The wide annular core optical fiber comprises a third quartz cladding and a third quartz fiber core, and the third quartz fiber core annularly wraps a third quartz layer; the annular core optical fiber comprises a fourth quartz inner wrapping layer, a fourth quartz fiber core and a fourth quartz outer wrapping layer, the fourth quartz inner wrapping layer is annularly wrapped by the fourth quartz fiber core, the fourth quartz fiber core is annularly wrapped by the fourth quartz outer wrapping layer, and the optical fiber radial refractive index distribution index of the gradient refractive index multimode optical fiber is 1.95-2. According to the scheme, the annular core optical fiber is used for injecting light to the gradient refractive index multimode optical fiber, two modes with smaller group velocity dispersion difference can be excited to interfere, and the sensitivity of the sensor is improved.

An optical waveguide is provided for arrangement in the beam path of an optical arrangement with a device for output coupling and / or input coupling an imaging beam path. The optical waveguide includes a GRIN element having at least one curved surface. The GRIN element has a refractive index distribution designed to reduce the aberrations, arising due to the curvature of the GRIN element, in an imaging path of a virtual image created by light waves guided in the optical waveguide by total-internal reflection.

An image display device according to one embodiment of the present disclosure comprises: a plurality of display pixels which are arranged in a two-dimensional array form; active layers which are respectively provided to the plurality of display pixels or which are provided straddling the plurality of display pixels; and a photonic crystal layer which is provided to at least some of the plurality of display pixels, which includes a defect in a periodic refractive index distribution that disrupts said periodic refractive index distribution, and in which neither the outer shape of the region having the periodic refractive index distribution nor the structure in the vicinity of the defect has rotational symmetry with respect to rotations of less than 180°.

The application discloses a seawall protection structure design method and system based on a winding space metasurface technology, relates to the technical field of seawall protection engineering, and comprises the following steps: selecting a suitable winding space metasurface unit model according to frequency parameters and wave height parameters of sea waves; designing and optimizing the winding space metasurface unit model based on a preset refractive index distribution; arranging and installing the designed winding space metasurface unit model array outside a seawall and debugging; and adjusting the arrangement and refractive index of the winding space metasurface unit model to cope with different sea wave conditions by monitoring sea conditions in real time. The application modulates the energy distribution of water surface waves, realizes focusing, scattering or absorption of the waves, effectively reduces the direct impact of the sea waves on the seawall, enhances the protection effect, and reduces the long-term maintenance cost.

The present invention aims to provide a multi-core optical fiber and a design method thereof, which configures four cores of a single-peak type with a standard cladding diameter, satisfies a desired specification, and is excellent in mass productivity, quality, and yield. The multi-core optical fiber of the present invention has four cores of a single-peak type refractive index profile with a radius a arranged in a square lattice shape in a long side direction, and a cladding region with a diameter of 125 ± 1 μm, which has a lower refractive index than the cores, and an absolute value of a relative refractive index difference from the cores is Δ, on an outer peripheral portion of the cores, and the four cores are arranged in a manner that a relationship of a minimum distance (OCT) from a center of the core to an outer periphery of the cladding region, a minimum value Λ of a pitch of the cores, and an MFD at a wavelength of 1310 nm satisfy a number C1, and the relative refractive index difference Δ of the cores and the cladding region and the radius a of the cores are set. [Number C1] OCT ≥ 3.73 MFD + 3.43 Λ ≤ -5.28 MFD + 83.54.