3689results about "Diffraction gratings" patented technology

A metalens for focusing light is described. The metalens includes a library of elements for varying the propagating phase of the focusing light over at least a 2π radians range, where the library of elements is arranged in a sub-wavelength pattern that defines spacings between the elements. Each spacing exhibiting temperature-dependent spacing changes within a temperature range and each element in the library of elements includes: a refractive index exhibiting a temperature-dependency within the temperature range, a shape exhibiting a temperature-dependency within the temperature range, and a size exhibiting a temperature-dependency within the temperature range. The metalens also includes a phase profile defined by a combination of the refractive index, shape, and size of each element in the library, and the sub-wavelength pattern of the library of elements. The metalens also includes a focal length defined by the phase profile, the focal length exhibiting a temperature-dependency within the temperature range.

The invention belongs to the technical field of laser, and discloses a grating multiplexing spectrum synthesis system, which comprises a beamlet dense array, a diffraction grating and a turn-back mirror, each beamlet emitted by the beamlet dense array is diffracted by the diffraction grating and then is emitted in the form of convergent light, and the light is reflected twice by the turn-back mirror to form a light beam; each laser sub-beam is incident on the diffraction grating again along the opposite direction parallel to the original light, the sub-beams converge into one point on the diffraction grating by adjusting the distance between the turn-back mirror and the diffraction grating, and at the moment, the incident angle of each sub-beam is equal to the diffraction angle diffracted from the diffraction grating for the first time; and the diffraction angles of the sub-beams subjected to the second diffraction on the diffraction grating are equal and equal to the incident angle of the sub-beams subjected to the first diffraction, that is, the synthesized light beam is emitted along the direction parallel to and opposite to the direction of the light beam emitted from the sub-beam dense array. The invention provides a spectrum synthesis system which is simple in structure, easy in engineering implementation and compact in volume.

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.

According to the device and the method for synchronously locking the phase and the period of the holographic interference fringes, two sets of locking devices are adopted and are respectively arranged at two ends of a holographic interference exposure field in the same direction as the period of the interference fringes, one set is used for compensating the phase of the interference light field to lock the phase of the interference fringes, and the other set is used for locking the period of the interference fringes. And the other one is used for compensating the output laser frequency of the laser to lock the interference fringe period. According to the interference fringe phase and period synchronous locking method, the problem that the contrast ratio of interference fringes is degraded due to phase and period drift of the interference fringes in the exposure process of a large-aperture holographic grating is solved, and particularly an interference fringe period real-time locking module is used; the problem that the fringe contrast is gradually deteriorated in the periodic direction due to periodic change of interference fringes is effectively solved, and a reliable solution is provided for preparation of the meter-scale large-aperture, high-contrast and high-uniformity holographic grating.

Gradient encapsulation of waveguide outcoupler gratings for control of diffraction efficiency and directionality includes a first grating formed over a substrate, the first grating having a plurality of first structures extending away from the substrate, the first grating corresponding to an outcoupler. The device includes a first encapsulant disposed in one or more gaps formed between adjacent first structures, where a fill ratio of the first encapsulant decreases along the first grating. Also described herein are methods for fabricating the device.

Provided are an optical element capable of more easily detecting a change in refractive index of an object to be measured without sweeping a wavelength of incidence light, and an optical sensor using the optical element. An optical element includes a liquid crystal layer that is formed of a composition including a liquid crystal compound, in which the liquid crystal layer has a liquid crystal alignment pattern in which an orientation of an optical axis derived from the liquid crystal compound changes while continuously rotating toward at least one direction of in-plane directions, in a case where a length over which the orientation of the optical axis derived from the liquid crystal compound rotates by 180° in a plane is set as a single period, a length of the single period in the liquid crystal alignment pattern gradually changes in the one direction, and the liquid crystal layer has a resonance structure.

The invention discloses a far-field imaging system, a metasurface grating and an imaging terminal, and relates to the technical field of image generation. Dynamic environment compensation and imaging quality optimization are realized through cooperation of multiple modules of the system: the environment temperature is read in real time, the refractive index of the metasurface grating is corrected according to a pre-stored mapping relation, and a target wavefront function is constructed and dispersed to obtain an initial phase distribution matrix; dividing a focusing area in combination with a user sight line, and compensating and regulating a phase distribution matrix by voltage gradient; based on the divided buffer and background regions, a multi-region sampling rate is configured to generate a mask, and the collection efficiency of the key region is improved; monitoring far-field information change in real time, and selecting an interpolation or total variation strategy to update the image; by means of image definition feedback, a secondary phase correction term is superposed to optimize a phase distribution matrix; the problems of traditional far-field imaging in the aspects of environment adaptation, dynamic focusing, data acquisition and imaging quality are solved, and the method is suitable for augmented reality glasses and the like.

The invention provides a continuous depth gradually-changing grating structure based on a silicon carbide substrate and a preparation method thereof. The preparation method comprises the following steps: forming a sacrificial layer with gradually-changing thickness on the silicon carbide substrate; etching is carried out by adopting a two-step plasma etching process; and polishing the surface through a plasma polishing process. According to the invention, the gradient sacrificial layer is combined with two-step plasma etching, and a high-precision continuous depth gradient grating structure is realized on the silicon carbide substrate, so that the diffraction requirements of RGB three-color wavelengths are met; the micro-groove defect in the etching process is eliminated, the problem that the depth-to-width ratio and the surface quality cannot be considered in the traditional process is solved, and a key technical support is provided for mass production of the single-layer full-color optical waveguide; the transmission loss of the optical waveguide is reduced by controlling the surface roughness; and the product yield is improved, the production cost is reduced, and the method is suitable for large-scale production.

The invention provides a grating assembly and a manufacturing method of the grating assembly. The grating assembly comprises a substrate; the number of the optical cement auxiliary structures is multiple, and the multiple optical cement auxiliary structures are formed on the surface of one side of the substrate at intervals through nanoimprint; the functional layer covers the sides, away from the substrate, of the optical cement auxiliary structures in a shape follow-up mode so that the side faces and the top faces of the optical cement auxiliary structures can be wrapped by the functional layer, and gaps are reserved in the sides, away from the substrate, of the functional layer; the optical adhesive layer is arranged on the side, away from the substrate, of the optical adhesive auxiliary structure, and the projection of the optical adhesive layer on the substrate completely covers the optical adhesive auxiliary structure and the functional layer; the functional layer is a deposition layer, the grating assembly further comprises a plurality of diffraction gratings, and the diffraction gratings are filled in the gaps. The problem that the diffraction efficiency of a grating assembly in the prior art is difficult to improve is solved.

The invention discloses an external cavity tunable laser linewidth compression system for realizing wavelength phase locking based on mutual injection of gain chips. The external cavity tunable laser linewidth compression system comprises a red light semiconductor laser main gain chip, a first collimation optical system, a blazed grating, a tuning rotating mirror, a reflector, a power supply driving system and a double-path feedback amplification system, the double-path feedback amplification system comprises a first secondary gain chip, a second secondary gain chip, a second collimation optical system, a third collimation optical system and a polarization-free beam splitter prism; and the red light semiconductor laser main gain chip, the first secondary gain chip and the second secondary gain chip are all connected with the power supply driving system. Therefore, the technical problems of low output infrared light power, poor stability and narrow mode-hopping-free tuning range in the prior art are solved, and high-power, narrow-linewidth, high-stability and large-range mode-hopping-free continuous tuning red light output can be realized.

An optical system comprises a first lens group having positive refractive power, a second lens group having positive refractive power, and a third lens group having negative refractive power, arranged in order from an object side, wherein, when focusing, the second lens group moves along an optical axis, and the optical system satisfies the conditional expressions 0.100<BFa / f<0.500 and −5.000<(−G1R1) / f<500.000, where BFa is an air equivalent distance on the optical axis between a lens surface on an image side of a lens disposed closest to an image and the image, f is a focal length of the optical system, and G1R1 is a radius of curvature of a lens surface on the object side for a lens component disposed farthest on the object side in the first lens group.

The invention discloses a preparation method of a polymer dispersed liquid crystal holographic grating with s polarization high diffraction characteristics, and belongs to the technical field of holographic optics. Raw materials comprise 60-90% of a thiol-ene monomer, 10-40% of liquid crystals, a photoinitiator accounting for 1.25% of the mass of the monomer, and a coinitiator accounting for 1.56% of the mass of the monomer. Light with the wavelength of 532 nm and the light intensity of 5-30 mW / cm < 2 > is used for carrying out double-interference photoetching to generate photochemical reaction so as to generate the polymer grating film, and the light is s polarized light. Under the optimal recording condition, delta n under s polarization can reach 1.93 * 10, and delta n under p polarization can reach 1.21 * 10. In combination with morphology analysis, it is found that refractive index modulation strongly depends on the proportion of a liquid crystal-rich phase to a polymer-rich phase in the grating. It is proved that the size of liquid crystal microdroplets formed by holographic recording is larger due to low recording intensity, and therefore the threshold driving voltage of the HPDLC grating is reduced.

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.

To allow systems for manufacturing waveguide cells in accordance with various embodiments to be configured and implemented in many different ways.SOLUTION: In many embodiments, various deposition mechanisms are used to deposit a layer(s) of an optical recording material(s) onto a transparent substrate. A second transparent substrate can be provided, and the three layers can be laminated to form a waveguide cell. A suitable optical recording material can vary widely depending on a given application. In some embodiments, the optical recording material deposited has a similar composition throughout a layer. In a number of embodiments, the optical recording material spatially varies in composition, enabling formation of optical elements with varying characteristics. Regardless of the composition of the optical recording material, any method of placing or depositing the optical recording material onto a substrate can be utilized.SELECTED DRAWING: Figure 11

Optical device films and methods of forming optical device films having a RMS surface roughness less than about 2.2 μin and a refractive index greater than 2.0 are provided. In one embodiment, an optical device film is provided and includes a crystalline or nano-crystalline material having a refractive index greater than 2.0. A top surface of the optical device film has a root-mean-square (RMS) surface roughness less than about 2.2 microinches (μin).

The invention relates to an optical monomer and a preparation method and application thereof, the structural general formula of the optical monomer is as follows: R1, R2 and R3 are respectively selected from one of hydrogen and C1-C4 alkyl, A1 is selected from one of hydrogen and C1-C4 alkyl, and A2 is C1-C4 alkyl; r4 is selected from one of H, phenyl and C1-C4 alkyl, and A2 is C1-C4 alkyl; and R5 is hydrogen or methyl. The optical monomer provided by the invention contains a (methyl) acrylate group, and has the properties of high refractive index and low volume shrinkage; and a plurality of aromatic rings with high molar refractive index and low molar volume are contained, so that the whole molecule of the whole monomer is extremely high in refractive index. The monomer structure provided by the invention has a plurality of branched chains, the overall molecular weight is small, and the molecules are not easy to agglomerate.

The invention provides a four-port single-mode grating filter combined with a semi-symmetric fano resonance structure, and relates to the field of optical communication and optical sensing, and the filter comprises an F-P cavity and two bending coupling waveguides which are symmetrical up and down; the F-P cavity is arranged between the two bent coupling waveguides; the Bragg grating comprises a central waveguide, a conical grating and a Bragg grating; and two small circular holes are formed in each bent coupling waveguide. According to the technical scheme of the invention, two circular small holes are designed in each of the upper and lower bent waveguides to construct a semi-symmetric Fano resonant structure, and the two groups of circular small holes are in central symmetry. By constructing a semi-symmetric Fano resonant structure, the transmission efficiency of the drop end on the four-port single-mode grating filter is improved.

The invention discloses a photovoltaic ecological system based on a holographic frequency division technology. The photovoltaic ecological system comprises a frame body; the frequency-division concentrating photovoltaic unit comprises a substrate layer which is formed by connecting a heat conducting plate and a dodging plate and is connected with the frame body through a reciprocating motion mechanism, a concentrating layer and a holographic grating layer which are sequentially arranged above the heat conducting plate, and a photoelectric conversion battery arranged on the heat conducting plate; the light adjusting unit is arranged between the two adjacent frequency division concentrating photovoltaic units and comprises two frequency division plates connected through a rotating pair, and the ends, away from each other, of the two frequency division plates are connected with the corresponding frequency division concentrating photovoltaic units through rotating pairs; the reflective optical baffles are arranged on the two sides of the substrate layer, and side wall batteries are further arranged on the sides, close to the light adjusting units, of the reflective optical baffles. According to the invention, through a spectrum frequency division and space light energy distribution mechanism, multi-band efficient utilization of sunlight is realized, the light quality and the light quantity required by plant photosynthesis are guaranteed, and the photovoltaic power generation efficiency is improved.

The invention provides a display screen and electronic equipment, the display screen comprises a cover plate, a light source assembly and at least one light processing structure, the cover plate is provided with a first side and a second side which are opposite to each other, the cover plate can transmit light, and an anti-dazzle structure is formed on the second side; the light source assembly is arranged on the first side of the cover plate and used for emitting first light to the direction of the cover plate. The light processing structure is arranged between the light source assembly and the anti-dazzle structure and used for changing the propagation direction of part of the first light. According to the display screen, the light intensity of the first light used for displaying the picture is reduced by arranging the light processing structure, so that the intensity of the formed flash point is reduced, the flash point can be visually shown to be not obvious, optimization of the flash point is achieved, eye fatigue is reduced, and user experience is improved.

Systems for the manufacturing of waveguide cells in accordance with various embodiments can be configured and implemented in many different ways. In many embodiments, various deposition mechanisms are used to deposit layer(s) of optical recording material onto a transparent substrate. A second transparent substrate can be provided, and the three layers can be laminated to form a waveguide cell. Suitable optical recording material can vary widely depending on the given application. In some embodiments, the optical recording material deposited has a similar composition throughout the layer. In a number of embodiments, the optical recording material spatially varies in composition, allowing for the formation of optical elements with varying characteristics. Regardless of the composition of the optical recording material, any method of placing or depositing the optical recording material onto a substrate can be utilized.

Embodiments of the present disclosure provide methods for forming optical device structures. An exemplary method generally includes disposing a first material device layer on a substrate; patterning a portion of the first material device layer to form a first plurality of device structures in the first material device layer; disposing a second material device layer on an unpatterned portion of the first device material layer; performing a nanoimprint lithography process on the second material device layer to form a second plurality of device structures on the first material device layer; and disposing a metal coating on the second plurality of device structures.

The embodiment of the invention provides a projection lens module and micro projection equipment. The projection lens module sequentially comprises a first lens group, a diaphragm and a second lens group from an object side to an image side along an optical axis; the first lens group comprises a first doublet lens and a third lens which are arranged along the optical axis, the first doublet lens has positive focal power, the third lens has negative focal power, and the first doublet lens can move along the optical axis to adjust the focal length of the projection lens module; the second lens group comprises a second doublet lens, a third doublet lens and an eighth lens which are sequentially arranged along the optical axis, the second doublet lens, the third doublet lens and the eighth lens all have positive focal power, the third doublet lens can move along the optical axis, and the eighth lens can move along the optical axis. The third lens is used for compensating image plane displacement caused by movement of the third lens so as to keep clear imaging; the diaphragm is located between the third lens and the second doublet lens.

The invention provides a volume holographic grating exposure parameter determination method and a two-dimensional pupil expansion volume holographic optical waveguide, and the method comprises the steps: carrying out the multiple rotation of a vector of a first light beam, a vector of a second light beam and a holographic photosensitive material when the wavelengths of the first light beam and the second light beam are first recording wavelengths, the rotated vectors of the first light beam and the second light beam and the rotated material position of the holographic photosensitive material are obtained; converting the wavelengths of the first light beam and the second light beam into a second recording wavelength, and rotating the rotated vectors of the first light beam and the second light beam at least once to obtain in-material vectors of the first light beam and the second light beam; determining the in-air vectors of the first light beam and the second light beam according to the in-material vectors of the first light beam and the second light beam; and determining incident angles of the first light beam and the second light beam according to the in-air vectors of the first light beam and the second light beam. According to the method, the manufacturing efficiency of the two-dimensional pupil-expanding body holographic optical waveguide comprising the coupling-in, turning and coupling-out body holographic grating can be improved.

Architectures are provided for optical devices such as waveguides including structures that are configured to selectively in-couple one or more streams of light from a multiplexed light stream into the waveguide. The multiplexed light stream can include light with different characteristics (e.g., different wavelengths and / or different polarizations). The waveguide can comprise one or more in-coupling elements that can selectively couple one or more streams of light from the multiplexed light stream into the waveguide while transmitting, e.g., without in-coupling, one or more other streams of light from the multiplexed light stream.

The invention relates to a waveguide grating, in particular to a method for manufacturing a waveguide grating with continuous gradually-changing groove depth, which comprises the following steps of: accurately measuring and calibrating ion beam current density distribution of a used ion beam in a working plane; establishing a cooperative control model associated with a target groove depth curve, ion beam current density distribution and scanning speed, associating the etching depth with the ion beam total dose, and accurately controlling the ion beam total dose received by each point on the waveguide grating by dynamically regulating and controlling the scanning speed of the substrate relative to the ion beam, so as to realize accurate control of the etching depth. The accurate control on the groove depth distribution is realized; based on the cooperative control model, the scanning speed corresponding to the target groove depth curve is solved by combining the set target groove depth curve and the calibrated ion beam current density distribution; and performing ion beam etching based on the solved scanning speed, and finally forming a continuous gradual change groove depth accurately corresponding to the target groove depth curve on the waveguide grating. The method can effectively overcome the defect that the high-precision waveguide grating with the continuous gradually-changing groove depth is difficult to manufacture.

Methods, apparatus, devices, and systems for displaying three-dimensional objects by individually diffracting different colors of light are provided. In one aspect, an optical device includes: a first optically diffractive component including a first diffractive structure configured to diffract a first color of light having a first incident angle at a first diffracted angle, a second optically diffractive component including a second diffractive structure configured to diffract a second color of light having a second incident angle at a second diffracted angle, a first reflective layer configured to totally reflect the first color of light having the first incident angle and transmit the second color of light, and a second reflective layer configured to totally reflect the second color of light having the second incident angle. The first reflective layer is between the first and second diffractive structures, and the second diffractive structure is between the first and second reflective layers.

To provide a zoo lens which has a large aperture ratio and a minimized total length, offers less shift in the center of gravity while zooming and focusing and quiet autofocusing, and is suitable for video shooting.SOLUTION: A zoom lens of the present invention consists of a first lens group G1 having negative refractive power, an intermediate lens group GM having positive refractive power as a whole, a rear lens group GR, and a final lens group GN arranged in order from the object side, the intermediate lens group GM consisting of three or more lens groups including a focusing lens group configured to move along an optical axis while focusing from infinity to a short distance, and the rear lens group consisting of one or more lens groups. When zooming from the wide-angle end to the telephoto end, distances between the lens groups change as the intermediate lens group GM moves toward the object side, increasing the distance between the intermediate lens group GM and the rear lens group GR. The first lens group G1 and the final lens gup GN are stationary while zooming and focusing.SELECTED DRAWING: Figure 1

One embodiment provides an apparatus for displaying an image comprising: a first optical substrate comprising at least one waveguide layer configured to propagate light in a first direction, wherein the at least one waveguide layer of the first optical substrate comprises at least one grating lamina configured to extract the light from the first substrate along the first direction; and a second optical substrate comprising at least one waveguide layer configured to propagate the light in a second direction, wherein the at least one waveguide layer of the second optical substrate comprises at least one grating lamina configured to extract light from the second substrate along the second direction; wherein the at least one grating lamina of at least one of the first and second optical substrates comprises an SBG in a passive mode.

The invention discloses a nano-pillar array NaKSb photoelectric cathode for enhancing light absorption, which is characterized in that through the design of a double-layer TiOtwo-dimensional nano grating and a nano-pillar array structured NaKSb photoelectric cathode layer, the optical path of light with the wave band of 450-900 nm in the photoelectric cathode is increased under the condition that the thickness of the NaKSb photoelectric cathode is not increased, the reflectivity of the wave band of 400-600 nm is reduced, and the light absorption of the NaKSb photoelectric cathode is enhanced. The absorption rate at 400-1000 nm is improved by 32.28% compared with that of a traditional planar film type photoelectric cathode, the absorption rate at 800-1000 nm near-infrared band is improved by 40.27% compared with that of the traditional planar film type photoelectric cathode, the problem that the absorption of the traditional planar film type photoelectric cathode near-infrared band is insufficient is solved, and the photoelectric cathode is suitable for high-performance low-light night vision imaging devices.

A variable magnification optical system consists of, in order from an object side, a front group, an intermediate group, and a subsequent group. The front group consists of two or fewer lens groups having a positive refractive power. The intermediate group consists of two or fewer lens groups having a negative refractive power. The subsequent group consists of a plurality of lens groups. A lens group of the subsequent group closest to the object side is a first subsequent lens group having a positive refractive power. Two or fewer focusing groups that move along an optical axis during focusing are disposed in the subsequent group. During magnification change, a lens group of the front group closest to the object side is fixed with respect to an image plane.