361 results about "Diffraction efficiency" patented technology

The invention belongs to the technical field of optical materials, and discloses a holographic polymer dispersed liquid crystal composition, a holographic grating and a preparation method. The composition comprises the following components in parts by mass: 0.5-1.5 parts of a photoinitiator, 2-5 parts of a co-initiator, 15-20 parts of a first monomer, 15-20 parts of a second monomer, 10-15 parts of a third monomer, 10-15 parts of a solvent and 10-20 parts of mixed liquid crystal. Wherein the first monomer is a monofunctional acrylic monomer, the second monomer is a bifunctional acrylic monomer, the third monomer is a polyfunctional acrylic monomer, the mixed liquid crystal comprises 10-25 wt% of a monomer liquid crystal and 75-90 wt% of a nematic liquid crystal, and the monomer liquid crystal contains fluorine as a benzene ring substituent and contains cyano or isothiocyano as an end group. Through cooperation of the monomer liquid crystal and the nematic liquid crystal in the mixed liquid crystal and cooperation of fluorine atoms and cyano / isothiocyano groups in the monomer liquid crystal, the holographic grating prepared from the composition has the characteristics of low haze and high diffraction efficiency, and the grating can be thinner, so that the requirements of light weight and clearness of AR glasses can be met.

The invention provides an acrylate monomer with a high refractive index and a preparation method and application thereof, the acrylate monomer has a structure as shown in a formula G1, G2 or G3, the refractive index of the acrylate monomer is 1.75 or above, so that a holographic recording medium has higher sensitivity and higher diffraction efficiency, and the holographic recording medium can be applied to the field of holographic recording. The holographic recording medium is used for a holographic grating, so that the holographic grating has high diffraction efficiency and high refractive index modulation degree.

The invention discloses a thiophene monomer, a holographic recording medium, a preparation method and a related device, the structural general formula of the thiophene monomer is shown in the specification, the refractive index of the monomer is larger than 1.8 and smaller than 1.9, the diffraction efficiency can be remarkably improved, the thiophene monomer is applied to preparation of a photopolymer type holographic recording medium, and the photopolymer type holographic recording medium with the sensitivity larger than 100 cm / mJ can be obtained. According to the holographic recording medium, the diffraction efficiency of the recording grating is larger than 95%, the refractive index modulation degree is larger than 0.1, and the shrinkage rate is lower than 1%, and further, the holographic recording medium can be used for preparing a volume holographic grating, a holographic optical element and an optical device.

The invention discloses a (methyl) acrylate monomer, a holographic recording medium, a preparation method and a related device.The structural formula of the (methyl) acrylate monomer is as shown in G1-G19. The preparation method is easy to operate and high in synthesis yield, and further, the holographic recording medium can be applied to holographic recording. According to the photopolymer holographic recording medium, the (methyl) acrylate monomer with the structure is introduced into the photopolymer holographic recording medium, so that the holographic recording medium with high sensitivity, high diffraction efficiency and no yellowing is obtained, and the invention further provides a preparation method of the holographic recording medium. The invention also provides a volume holographic grating, a holographic optical element and an optical device comprising the holographic recording medium.

The invention discloses a thianthrene monomer, a holographic recording medium, a preparation method and a related device, the structural formula of the thianthrene monomer is shown as G1-G6, the refractive index of the thianthrene monomer is larger than 1.7 and smaller than 1.8, the diffraction efficiency can be remarkably improved, and further, the holographic recording medium can be applied to holographic recording. The thianthrene monomer with the structure is introduced into the photopolymer type holographic recording medium, so that the holographic recording medium with high sensitivity, high diffraction efficiency and high refractive index is obtained, and the invention further provides a preparation method of the holographic recording medium. The invention also provides a volume holographic grating, a holographic optical element and an optical device comprising the holographic recording medium.

The invention discloses a (methyl) acrylate monomer, a holographic recording medium, a preparation method and a related device.The structural formula of the (methyl) acrylate monomer is as shown in G1-G5. The preparation method is easy to operate and high in synthesis yield, and further, the holographic recording medium can be applied to holographic recording. The (methyl) acrylate monomer with the structure is introduced into the photopolymer type holographic recording medium, reverse migration of a short polymer chain can be effectively inhibited, and therefore the holographic recording medium with high sensitivity and high diffraction efficiency is obtained, and the invention further provides a preparation method of the holographic recording medium. The invention also provides a volume holographic grating, a holographic optical element and an optical device comprising the holographic recording medium.

The invention relates to a laser radar on-chip integrated chip based on acousto-optic modulation, an on-chip acousto-optic scanning method and a laser radar system. A plurality of groups of interdigital transducers are arranged on the lithium niobate film, two groups of chirp IDTs respectively work at a low-frequency band and a high-frequency band, and sound waves at the low-frequency band correspondingly generate a relatively large Bragg deflection angle; and the high-frequency-band sound waves correspondingly generate a relatively small Bragg deflection angle. The two groups of IDTs work cooperatively, so that two-dimensional vector scanning of a dual-frequency broadband can be realized in a chip plane; the pair of focusing IDTs can form a focusing sound field in an action area, so that the light beam subjected to two-dimensional deflection is controllably deflected in the Z direction, and the chip is endowed with the three-dimensional scanning capability. The device is high in diffraction efficiency and low in power consumption; unification of large-range search and high-precision scanning is realized; z-axis deflection is realized by integrating a special focusing type interdigital transducer, a three-dimensional scanning function is realized on a monolithic integrated acousto-optic chip, and the structure is extremely compact.

The present invention relates to a transmission grating and a preparation method therefor. The transmission grating comprises: a substrate, which has a first surface; a grating layer, which comprises trapezoidal grating teeth arranged in an array on the first surface, wherein the grating teeth extend in the direction of thickness of the substrate, and a gap is provided between two adjacent grating teeth; and a dielectric layer, which is arranged on a surface of the grating layer and fills the gaps, wherein the dielectric layer has a second surface on the side thereof away from the substrate; there is a difference between the height of the grating teeth and the distance between the second surface and the first surface, the difference being m; and incident light passes through the interior of the grating layer and is incident towards the second surface. By means of the design of a film layer structure and film layer dimensions of the transmission grating, the present invention can acquire transmission gratings having different diffraction efficiencies and polarization degrees, and can accurately control the dimensions of the film layer structure of the transmission grating during machining, thereby facilitating machining.

The invention discloses a dendritic (methyl) acrylate monomer, a holographic recording medium, a preparation method and a related device. Wherein the structural formula of the dendritic (methyl) acrylate monomer is shown as G1-G12, the preparation method of the dendritic (methyl) acrylate monomer is simple and easy to operate, and further, the dendritic (methyl) acrylate monomer with the structure is introduced into the photopolymer type holographic recording medium, so that the photopolymer type holographic recording medium is prepared. The invention further provides a preparation method of the holographic recording medium, a volume holographic grating containing the holographic recording medium, a holographic optical element containing the holographic recording medium and an optical device containing the holographic recording medium.

The invention provides a polymerizable monomer with the refractive index larger than 1.7 and a preparation method and application thereof.The polymerizable monomer has the structure shown in the formula G1 or G2 or G3 or G4 or G5 or G6, the refractive index of the polymerizable monomer is 1.7 or above, and therefore a holographic recording medium has various excellent characteristics such as high sensitivity, high diffraction efficiency and high refractive index modulation degree; the holographic recording medium is used for a holographic grating, so that the holographic grating has high diffraction efficiency and high refractive index modulation degree.

The invention discloses a 4, 4 '-bis (omega-alkenyl thioether) diphenyl sulfide monomer and a preparation method, the structural general formula of the 4, 4'-bis (omega-alkenyl thioether) diphenyl sulfide monomer is shown in the specification, n represents the number of methylene and is a positive integer, n = 1-10, the refractive index of a polymer obtained after the monomer and 4 '4-dimercapto diphenyl sulfide are polymerized is larger than 1.65 and smaller than 1.8, diffraction efficiency is remarkably improved, the preparation method is easy to operate, and the preparation method is suitable for industrial production. The invention further provides a photopolymer type holographic recording medium containing the monomer and a preparation method of the photopolymer type holographic recording medium, the sensitivity of the holographic recording medium is larger than 100 cm / mJ, the diffraction efficiency of a recording grating is larger than 95%, the refractive index modulation degree is larger than 0.1, the shrinkage rate is lower than 1%, and the preparation method is simple, controllable and suitable for industrial production. The invention also provides a volume holographic grating containing the holographic recording medium, a holographic optical element and an optical device.

The invention discloses a dithiocarbamate monomer, a holographic recording medium, a preparation method and a related device, the structural general formula of the monomer is as shown in G1 and G2, R1 represents any one of hydrogen, halogen and C1-C4 alkyl, R3 represents any one of hydrogen, halogen and C1-C4 alkyl, A1 represents C1-C4 alkyl, A2 represents hydrogen or methyl, n is a positive integer, and n = 1-10. The dithiocarbamate monomer provided by the invention has high refractive index, and the holographic recording medium with high sensitivity, high diffraction efficiency and high refractive index modulation degree can be obtained by applying the dithiocarbamate monomer to preparation of the photopolymer holographic recording medium; holographic recording media can be used to prepare volume holographic gratings, holographic optical elements, and optical devices.

The application relates to a kind of diffractive optical element beam shaping methods based on spatial frequency filtering, obtain incident light beam, based on the homogenization light beam of preset, obtain corresponding geometric analytical phase distribution;Adjust the homogenization light beam to rectangular flat-top light beam, the phase correction processing of obtained geometric analytical phase;Based on spatial frequency filtering method processing the geometric analytical phase after phase correction, get the light field regulation and control distribution requirement after processing, the light field regulation and control distribution requirement after processing has phase and amplitude regulation and control requirement simultaneously;Design diffractive optical element, make it realize the light field regulation and control distribution requirement required, and utilize the diffractive optical element to realize the incident light beam shaping as the rectangular flat-top light beam.The application can realize the light beam homogenization effect of high uniformity, edge sharp and high diffraction efficiency, and obtain wide application prospect in laser welding, photoetching and biomedical and other aspects.

A volume holographic grating, a method for formulating a grating vector distribution formulation thereof, and a method and apparatus for manufacturing the volume holographic grating. The grating vector distribution is estimated by sampling a position of an eye movement range effective region of a plurality of sub-fields of view and a grating vector, matching with Bragg diffraction conditions, of a ray thereof, without considering the diffraction of ineffective rays that ultimately enter beyond the eye movement range, such that most of the effective rays with different incident angles have higher diffraction efficiency on the volume holographic grating, which ensures the overall brightness uniformity of the output beams and extend the field of view.

The invention is suitable for the field of electrochemical luminescence detection equipment, and provides a dispersion device suitable for electrochemical luminescence detection, which comprises a monochromator body, the monochromator body is composed of a monochromator housing, a reflector assembly, a grating assembly, a collimating mirror assembly, a focus lens assembly, a slit, a flange snap ring and a flange; an M-shaped light path is arranged in the monochromator body, and a slit, a reflector assembly, a collimating mirror M1 in the collimating mirror assembly, a customized blazed grating G1 in the grating assembly and a focusing mirror M2 in the focusing mirror assembly are sequentially arranged in the light propagation direction. The customized blazed grating G1 is designed by adopting specific parameters including the scribed line density, the blazed wavelength, the notch groove depth and the groove width ratio, and primary light energy enhancement and secondary light intensity suppression can be realized; according to the invention, an optical filter is not needed, the diffraction efficiency of a monochromator is improved to 60-86%, the intensity ratio of luminol secondary light to primary light is less than or equal to 1.6%, the detection limit of ruthenium bipyridine is reduced from 100pmol / L to 50pmol / L, and the electrochemical luminescence detection device is suitable for various electrochemical luminescence detection scenes.

The invention relates to a broadband continuous testing device and method for diffraction efficiency of a medium-long wave infrared grating. The device comprises a broadband light source, a medium-long wave infrared monochromator, a collimation system, a polarization selection system, a broadband spectrum beam splitting system, a signal enhancement detection system, a sample clamping and multi-dimensional moving system and an automatic control system. According to the testing method, the absolute diffraction efficiency of the grating is tested through double optical paths, measurement errors caused by fluctuation of a light source can be avoided, the measurement errors are further reduced by deducting environmental noise and improving the signal-to-noise ratio through a signal enhancement detection system, an automatic control system is added, and continuous scanning testing in a specified wave band is achieved. The test speed is improved. By means of the device and the method, automatic and rapid measurement of the diffraction efficiency of the medium-long wave echelette grating under the conditions of at least 2.5-14 micron broadband, different wavelengths, any incident angle and dual polarization states can be achieved.

The invention relates to the technical field of metasurface gratings, and discloses a synchronous testing system and method for diffraction efficiency and field angle of metasurface grating waveguide, and the system comprises a light source module which responds to a preset target field angle range, encodes the phase and frequency of a light beam through a composite encoding method, and obtains an incident light beam; the diffraction module is used for dividing the metasurface grating waveguide into a plurality of sub-regions, respectively inputting an incident light beam into each sub-region for diffraction, and collecting a diffracted light beam diffracted by the metasurface grating waveguide in each sub-region; the parameter coupling module is used for performing coupling calculation on a plurality of parameters in the diffracted beams of each sub-region through a parameter coupling method to generate a coupling matrix; the decoupling analysis module decouples the coupling matrix through a preset parameter decoupling model to obtain the diffraction efficiency and the field angle of the metasurface grating waveguide; according to the invention, high-precision synchronous measurement of the diffraction efficiency and the field angle of the metasurface grating waveguide can be realized.

The invention discloses an optical monomer, a holographic recording medium, a preparation method and a related device, the structural general formula of the optical monomer is as shown in G1-G6, the monomer is high in refractive index, the preparation method is simple, and further, the optical monomer with the structure is introduced into the photopolymer type holographic recording medium, so that the photopolymer type holographic recording medium is prepared. The invention further provides a preparation method of the holographic recording medium, a volume holographic grating containing the holographic recording medium, a holographic optical element containing the holographic recording medium and an optical device containing the holographic recording medium.

The invention discloses an unsaturated phenyl ether monomer, a holographic recording medium, a preparation method and a related device, the structural general formula of the monomer is as shown in G1 and G2, R1 represents any one of R2, A1 and A2 independently represent any one of hydrogen and phenyl, A3 represents hydrogen or methyl, A4 represents C1-C4 alkyl or phenyl, n is a positive integer and n = 1-5. The unsaturated phenyl ether monomer provided by the invention has high refractive index and is in a liquid state, and the holographic recording medium with high sensitivity, high diffraction efficiency and high refractive index modulation degree can be obtained by applying the unsaturated phenyl ether monomer to preparation of the photopolymer type holographic recording medium.

The invention discloses a PVG optical waveguide diffraction efficiency uniformity detection method and system, and aims to provide a scheme for comprehensively evaluating optical waveguide diffraction efficiency uniformity and polarization characteristic evaluation, and the method comprises the following steps: constructing and configuring a light source; image acquisition and preprocessing; performing diffraction efficiency analysis and uniformity evaluation; identifying defects; fusing multi-view results; verifying polarization response consistency; and generating a detection report containing the diffraction efficiency heat map of the optical waveguide to be detected, defect distribution and a polarization response curve. On the premise that the structure of the optical waveguide is not damaged, diffraction efficiency uniformity quantification, polarization consistency evaluation and defect identification of the optical waveguide in the whole field of view are achieved, the diffraction performance of the optical waveguide is evaluated globally, the detection accuracy, stability and automation level of a waveguide device are remarkably improved, and the detection efficiency is improved. Efficient and standardized technical support is provided for design, manufacturing and quality control of the optical waveguide, and a key quality control means is further provided for industrialized mass production of AR near-to-eye display modules.

The application belongs to the field of spectral measurement and imaging, and specifically discloses a single-photon detection device and a rapid spectral and imaging system based on the same. According to the application, a transmission optical fiber spectrometer separates each waveband complex light according to wavelength in space, and couples the photons of different wavelengths into an optical fiber array for time delay, so that the different wavelengths are delayed to different time points and output to a single-photon detection device. The single-photon detection device converts the photons of different wavelengths arriving at the device in time sequence into electrical signals, and obtains the number of photons at different time points after amplification and signal processing, and converts the number of photons into a spectrum. Since the transmission spectrometer can provide higher diffraction efficiency, higher spectral resolution and signal strength, the single-photon detection device can provide a faster and more accurate photon discrimination and photon counting method, and compared with the prior art, the whole can measure the spectrum more quickly, and has higher spectral resolution and signal strength.

This application discloses a method and system for synchronous testing of metasurface grating waveguide performance, relating to the field of metasurface grating technology. The method includes polarization state modulation and spatial frequency encoding of multi-wavelength incident beams to obtain a modulated incident light field; coupling this modulated incident light field into the metasurface grating waveguide under test, which then undergoes total internal reflection to form the outgoing light field; acquiring a raw dataset of the entire light field, including Stokes polarization images and spatial spectrum images corresponding to each wavelength of the outgoing beam; calculating the total internal reflection hop count based on the Stokes polarization image; calculating the spatial step size offset based on the spatial spectrum image; and establishing a mapping relationship between the image pixel coordinates of the raw dataset and the internal physical regions of the metasurface grating waveguide under test to obtain local diffraction efficiency distribution data. This application solves the problem that traditional outgoing end intensity testing is difficult to trace to local defects inside the waveguide, achieving synchronous, high-precision quantitative characterization of local diffraction efficiency across multiple wavelengths.

A transparent wood surface imprinting optical device is provided. A preparation method for the device includes cleaning and drying surfaces of transparent wood, spin-coating polymethyl methacrylate (PMMA) on a substrate of the transparent wood to obtain a PMMA layer, and spin-coating an ultraviolet (UV) glue on the PMMA layer to obtain a UV glue layer; placing the transparent wood on a silicon wafer, attaching a transparent grating array imprinting template on the UV glue layer, exposing the UV glue layer, and removing the transparent grating array imprinting after the exposing, thereby to obtain a grating-structure-based transparent wood; and replacing the grating structure imprinting template by a lattice structure imprinting template to prepare lattice-structure-based transparent wood. The diffraction efficiency of the grating structure and the lattice structure on the transparent wood are greater and more stable than those of PMMA substrates.

The application relates to the technical field of micro-nano machining, and discloses a kind of optical waveguide manufacturing template and its processing method, working template and diffractive optical waveguide manufacturing method.The optical waveguide manufacturing template includes template base and etching layer arranged on the surface of the template base, at least two groups of optical waveguide microstructures are arranged on the etching layer, and the depth of each group of optical waveguide microstructures is different.The thickness of the etching layer is configured to be able to meet the maximum design depth of each group of optical waveguide microstructures.The bottoms of different groups of optical waveguide microstructures are flush, and the tops are not flush.After implementing the technical scheme of the application, the technical problems of the prior art, such as complicated processing technology of multi-depth optical waveguide microstructure template, high overlay precision requirement, high manufacturing cost, low yield, low diffraction efficiency of depth microstructure due to imprinting residual glue during processing and poor display effect, are solved.

The polarization diffraction spectrometer comprises a substrate and a plurality of rectangular nano-columns arranged on the substrate, the rectangular nano-columns are periodically stacked or arranged in the height direction to form a periodic superlattice unit, and the substrate layer is made of a nanoscale transparent medium material; according to a grating equation, the optimal diffraction series, the period length and the incident light wavelength of the super grating are selected through experimental simulation, and optimal structural parameters are determined by combining an electromagnetic simulation tool and an optimization algorithm; the heights, the widths and the intervals of the rectangular nanocolumns serve as parameters of a particle swarm optimization algorithm, a fitness function with target diffraction order energy concentration ratio and target order overall diffraction efficiency optimization serving as core indexes is constructed, full-wave optical simulation software is combined, and geometric distribution in periodic units of the rectangular nanocolumns is optimized and adjusted. According to the invention, under the incident condition of 45-degree linearly polarized light, the S polarization component and the P polarization component are respectively concentrated at the preset target diffraction order, and an efficient diffraction light splitting effect is achieved.

The invention discloses an optical fiber laser external cavity spectrum synthesis crosstalk elimination method, which relates to the technical field of laser, and comprises the following four steps of: firstly, designing and constructing a spectrum synthesis system model by taking a reflection-type volume Bragg grating (R-VBG) as a beam combiner, and blocking a crosstalk path through R-VBG wavelength selective transmission and diffraction and grid line vertical design; calculating an optimal grating parameter by combining R-VBG loss and diffraction efficiency correlation and multi-parameter internal relation; a steady-state rate equation is deduced based on a three-energy-level system, and a pumping threshold power change rule and an output characteristic expression are obtained; and finally analyzing the influence of light beam characteristics and thermal deformation on diffraction efficiency, determining a threshold value and controlling temperature, and verifying the system performance through experiments. The method can fundamentally eliminate crosstalk, guarantee the quality of the light beam, balance the cost and loss, adapt to a multi-channel scene, and have a remarkable application value in a multi-field high-power fiber laser.

This invention discloses an accelerated simulation method and related apparatus for a graded periodic polarizer holographic grating. The invention performs D(k) calculations on the predicted direction of the incident light after passing through the grating layer. in After calculation, the result is multiplied by the corresponding incident light amplitude to calculate the diffraction efficiency. Compared with the traditional simulation method that uses complete and rigorous coupled wave calculation, this method reduces the number of integrations, matrix multiplications and matrix inversions, which can greatly accelerate the simulation speed.

The invention discloses a liquid crystal composition which comprises at least one of compounds in a general formula I, at least one of compounds in a general formula II and at least one of compounds in a general formula III. According to the invention, the liquid crystal composition has a high refractive index. Specifically, the compound as shown in the general formula I can increase the intersolubility of the liquid crystal composition while providing a relatively high refractive index for the liquid crystal composition, and has good stability to both photoelectricity and thermoelectricity; the compound in the general formula II can keep good solubility with other compounds while providing a relatively high refractive index for the liquid crystal composition; and the compound in the general formula III is an ester liquid crystal monomer compound, so that the liquid crystal composition has more diversity, and the stability of the whole liquid crystal system is higher. The invention also discloses a holographic polymer dispersed liquid crystal grating which has higher diffraction efficiency and refractive index modulation degree.

The application discloses a grating coupler, an optical waveguide device and a display device. The grating coupler couples input light incident thereon into a waveguide substrate and makes it propagate in the waveguide by total reflection, and comprises a grating body and an optical coating. The grating body comprises a plurality of unit structures arranged according to a predetermined grating period, and the optical coating covers the grating body and comprises one or more film layers. The grating coupler has one or more grating vectors, and the average thickness of at least one film layer in the optical coating gradually decreases in the direction of the at least one grating vector within a single grating period. By adopting the optical film layer with the thickness gradually decreasing in the coupling-in direction / grating vector direction, the grating coupler has a higher positive first-order diffraction efficiency in the upstream area of the coupling-in direction / grating vector direction and a lower coupling-out loss in the downstream area, so that the overall coupling-in efficiency of the grating coupler is maximized.

A diffractive optical waveguide and a display device having the same are disclosed. The diffractive optical waveguide includes a grating structure formed on a surface of a waveguide substrate, the grating structure including a plurality of grating lines arranged in a plane, the grating lines each extending along a first direction in the plane and arranged at a predetermined interval in a second direction perpendicular to the first direction; at least one sidewall of each grating line having a periodic structure along the first direction; and the grating structure configured to diffract light incident thereon at a non-zero angle with respect to the plane out of the plane through a predetermined diffraction order. The grating structure employed in the above-described diffractive optical waveguide can be used to adjust the diffraction efficiency at different angles and / or different diffraction orders, thereby providing a new effective and flexible means for improving the angular uniformity and / or the out-coupling efficiency of the diffractive optical waveguide.