Abstract: A photonic integrated circuit assembly generates light for use in a display system or a depth sensing system. The photonic integrated circuit assembly includes optical conditioning elements integrated into a photonic integrated circuit. The photonic integrated circuit includes one or more light sources on the photonic integrated circuit. The photonic integrated circuit includes a waveguide and one or more gratings located in a core of the photonic integrated circuit. The gratings may collimate and/or collocate light emitted by the light source. The photonic integrated circuit may include a beam shaping element integrated into the photonic integrated circuit. A MEMS scanner may use the collocated and/or collimated light emitted by the photonic integrated circuit to generate a display for a user or to generate a structured light pattern for use in a depth sensing system.

Abstract: An optical device for coupling light propagating between a waveguide and an optical transmission component is provided. The optical device including a taper portion and a grating portion. The grating portion is connected to the taper portion. The grating portion includes grating patterns. Ends of the grating patterns are separated from an outer edge of the optical device by a distance.

Abstract: A structure of a silicon photonics device for LIDAR includes a first insulating structure and a second insulating structure disposed above one or more etched silicon structures overlying a substrate member. A metal layer is disposed above the first insulating structure without a prior deposition of a diffusion barrier and adhesion layer. A thin insulating structure is disposed above the second insulating structure. A first configuration of the metal layer, the first insulating structure and the one or more etched silicon structures forms a free-space coupler. A second configuration of the thin insulating structure above the second insulating structure forms an edge coupler.

Abstract: Techniques for producing an overcoat layer on slanted surface-relief structures and devices obtained using the techniques are disclosed. In some embodiments, a method of planarizing an overcoat layer over a surface-relief structure includes removing a portion of the overcoat layer using an ion beam at a glancing angle. The overcoat layer includes planar surface portions and non-planar surface portions. Each of the non-planar surface portions includes a first sloped side and a second sloped side facing the first sloped side. The glancing angle is selected such that the first sloped side of each non-planar surface portion is shadowed from the ion beam by an adjacent planar surface portion such that the ion beam does not reach at least the first sloped side of each non-planar surface portion but reaches the second sloped side of each non-planar surface portion.

Abstract: A manufacturing system performs a deposition of an etch-compatible film over a substrate. The etch-compatible film includes a first surface and a second surface opposite to the first surface. The manufacturing system performs a partial removal of the etch-compatible film to create a surface profile on the first surface with a plurality of depths relative to the substrate. The manufacturing system performs a deposition of a second material over the profile created in the etch-compatible film. The manufacturing system performs a planarization of the second material to obtain a plurality of etch heights of the second material in accordance with the plurality of depths in the profile created in the etch-compatible film. The manufacturing system performs a lithographic patterning of a photoresist deposited over the planarized second material to obtain the plurality of etch heights and one or more duty cycles in the second material.

Abstract: A method, system, and computer program product for using photorefractive material for analog optic storage and other applications of optical neuromorphic systems. The method may include coupling electromagnetic radiation into a first optical input and a second optical input, where the first optical input and the second optical input are part of an integrated optical device, the integrated optical device including: a first optical mode coupler connected to a first pair of optical ports including a first optical input and output; a second optical mode coupler connected to a second pair of optical ports including a second optical input and output, and the first optical mode coupler connected to the second optical mode coupler using a pair of arms (including a photorefractive material). The method may also include obtaining an optical interference pattern in the photorefractive material of each arm of the integrated optical device.

Abstract: An optical grating component may include a substrate, and an optical grating, the optical grating being disposed on the substrate. The optical grating may include a plurality of angled structures, disposed at a non-zero angle of inclination with respect to a perpendicular to a plane of the substrate, wherein the plurality of angled structures are arranged to define a variable depth along a first direction, the first direction being parallel to the plane of the substrate.

Abstract: A surface-relief structure comprises a surface-relief grating including a first material characterized by a first refractive index, a first layer of a second material having a second refractive index conformally deposited on surfaces of the surface-relief grating, and a second layer of a third material having a third refractive index conformally deposited on the first layer. The effective refractive index of the combination of the first layer and the second layer is less than, equal to, or greater than the first refractive index, thereby increasing the duty cycle and/or modifying the overall refractive index of the surface-relief structure. The first layer and the second layer are deposited using, for example, atomic layer deposition techniques.

Abstract: A millimeter scale weak grating coupler comprising a silicon waveguide having bars of overlay material of length (a) disposed periodically at a period (?) adjacent the silicon waveguide whereby a uniform grating output is achieved.

Abstract: Structures including a grating coupler and methods of fabricating a structure including a grating coupler. The structure includes structure includes a dielectric layer on a substrate, a first waveguide core positioned in a first level over the dielectric layer, and a second waveguide core positioned in a second level over the dielectric layer. The second level differs in elevation above the dielectric layer from the first level. The first waveguide core includes a tapered section. The structure further includes a grating coupler having a plurality of segments positioned in the second level adjacent to the second waveguide core. The segments of the grating coupler and the tapered section of the first waveguide core are positioned in an overlapping arrangement.

Abstract: Embodiments of the invention describe apparatuses, optical systems, and methods for utilizing a dynamically reconfigurable optical transmitter. A laser array outputs a plurality of laser signals (which may further be modulated based on electrical signals), each of the plurality of laser signals having a wavelength, wherein the wavelength of each of the plurality of laser signals is tunable based on other electrical signals. An optical router receives the plurality of (modulated) laser signals at input ports and outputs the plurality of received (modulated) laser signals to one or more output ports based on the tuned wavelength of each of the plurality of received laser signals. This reconfigurable transmitter enables dynamic bandwidth allocation for multiple destinations via the tuning of the laser wavelengths.

Abstract: Optical communication modules, optical communication cables, and associated methods of manufacturing are provided. An example optical communication module includes a substrate supporting a first optical transceiver and a second optical transceiver. The first optical transceiver includes a first optical transmitter that generates optical signals having a first wavelength and a first optical receiver that receives optical signals having a second wavelength. The second optical transceiver includes a second optical transmitter that generates optical signals having the second wavelength and a second optical receiver that receives optical signals having the first wavelength. One or more lens assemblies coupled with the respective transceivers may be used to direct optical signal generated by and directed to the respective transceivers.

Abstract: 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.

Abstract: In accordance with an embodiment, a bandpass transmission filter having a center wavelength of transmission includes: a waveguide structure comprising a grating structure having changing grating pitch values configured to diffract radiation in the waveguide structure having a first wavelength lower than the center wavelength of transmission, and configured to reflect radiation in the waveguide structure having a second wavelength higher than the center wavelength of transmission; and a radiation absorbing structure configured to absorb radiation guided by the waveguide structure having a third wavelength higher than the second wavelength, wherein the radiation absorbing structure is an integrated part of the waveguide structure or comprises a layer arranged adjacent to the waveguide structure.

Abstract: Systems and embodiments for an integrated photonics mode splitter and converter are provided herein. In certain embodiments, a system includes a substrate having a first index of refraction. Additionally, the system includes a waveguide layer on the substrate, wherein the waveguide has a second index of refraction different from the first index of refraction. Also, the waveguide layer includes one or more mode splitters that receive at least one of a first photon in a first mode and a second photon in a second mode through an input port and provide one of the first photon through a first output port and the second photon through a second output port. The waveguide layer also includes a mode converter coupled to the second output of a mode splitter, wherein the mode converter receives the second photon through a port and outputs the second photon in the first mode through the port.

Abstract: Disclosed herein are multi-layer wavelength-division multiplexing (WDM) devices that include a first optical signal router to route first demultiplexed signals from a common layer to a first channel layer and a second optical signal router to route second demultiplexed signals from the common layer to a second channel layer.

Abstract: Embodiments of the present disclosure are directed to techniques for manufacturing an eyepiece (or eyepiece layer) by applying multiple, different diffraction gratings to a single side of an eyepiece substrate instead of applying different gratings to different sides (e.g., opposite surfaces) of the substrate. Embodiments are also directed to the eyepiece (or eyepiece layer) that is arranged to have multiple, different diffraction gratings on a single side of the eyepiece substrate. In some embodiments, two or more grating patterns are superimposed to create a combination pattern in a template (e.g., a master), which is then used to apply the combination pattern to a single side of the eyepiece substrate. In some embodiments, multiple layers of patterned material (e.g., with differing refraction indices) are applied to a single side of the substrate. In some examples, the combined grating patterns are orthogonal pupil expander and exit pupil expander grating patterns.

Abstract: An image capturing device (202) can include a sensor array (210), a lens (230) positioned at a first distance from an intermediate image (235), and apolychromat (220) positioned at a second distance from the lens (230). The polychromat (220) can diffract the intermediate image (235) according to a transform function (207) to produce a dispersed sensor image (215) onto the sensor array (210). The dispersed sensor image (215) can represent a spatial code of the intermediate image (235).

Abstract: An optical communications system includes a laser transmitter to generate an optical signal and a first optical fiber network coupled to transmit the optical signal from the laser transmitter system. A first latchable, asymmetric coupler is disposed along the first optical fiber network to receive the optical signal, and has a first tap output that receives a selected and alterable first fraction of the optical signal. A second latchable, asymmetric coupler is disposed along the first optical fiber network to receive the optical signal from the first latchable asymmetric coupler and has a second tap output that receives a selected and alterable second fraction of the optical signal incident at the second latchable. In certain embodiments the first and second couplers are capable of operating at any of at least three tapping fractions.

Abstract: A rendering device that renders a three-dimensional object displayed in a virtual reality space on a display includes a processor and a memory storing instructions that, when executed by the processor, cause the processor to render the 3D object as a 3D object of 3D displaying in a virtual reality space coordinate system, render the 3D object as a 3D object of 2D displaying in a plane coordinate system, and update displaying of the display based on a result of the 3D object being rendered as the 3D object of 3D displaying in the virtual reality space coordinate system and a result of the object being rendered as the 3D object of 2D displaying in the plane coordinate system. The rendering device enables intuitive drawing with high accuracy in the virtual reality space.

Abstract: A waveguide assembly is provided. The waveguide assembly includes a pair of pupil-replicating waveguides. The first pupil-replicating waveguide is configured for receiving an input beam of image light and providing an intermediate beam comprising multiple offset portions of the input beam. The second pupil-replicating waveguide is configured for receiving the intermediate beam from the first pupil-replicating waveguide and providing an output beam comprising multiple offset portions of the intermediate beam. The input beam may be expanded by the waveguide assembly in such a manner that pupil gaps are reduced or eliminated.

Abstract: A signal processing system includes a time domain processing module to receive samples of a range-dependent time domain baseband signal in a frequency modulated continuous wave (FMCW) LIDAR system, and to generate and select time domain subband signals based on time domain subband selection criteria, a time domain to frequency domain converter coupled with the time domain processing module, to generate range-dependent frequency outputs from the selected time domain subbands, and a frequency domain processing module coupled with the time domain to frequency domain converter, to generate and select frequency domain subbands based on frequency domain subband collection criteria, and to detect energy peaks corresponding to target ranges in the field of view of the LIDAR system.

Abstract: The invention relates to an optical fiber sensing device (1) for sensing the distribution of the compression/deformation of a compressible/deformable element (2), comprising: an incompressible/undeformable tubular element (3) with a recess (4) extending in a length direction (X) thereof, the recess being enclosed by the tubular element, an optical fiber (5) arranged in the recess, comprising one or more light distortion structures (6), and being expandable in the length direction of the recess, one or more expandable elements (8), having a higher compressibility/deformability than the tubular element in a transverse direction (Y), arranged at one or both ends (9) of the tubular element, the optical fiber being enclosed in the expandable elements, which are arranged for expanding/contracting in the length direction, along with the optical fiber, when the expandable elements are subjected to a transverse load (F).

Abstract: The present disclosure provides for two-dimensional mode matching by receiving an optical signal traveling in a first direction; and scattering the optical signal according to a scattering strength that progressively changes in the first direction. In various embodiments, the scattering strength progressively changes by increasing or decreasing in the first direction. A plurality of scatterers disposed in a path of the optical signal change in widths that progressively increase or decrease along the first direction. In various embodiments, a second optical signal is received in the grating coupler from a second direction; and is scattered into a surface of a photonic chip via a grating coupler. In some embodiments, the second direction is perpendicular to the first direction.

Abstract: An integrated optoelectronic or optical device is formed by a polarization-splitting grating coupler including two optical waveguides, a common optical coupler and flared optical transitions between the optical coupler and the optical waveguides. The optical coupler is configured for supporting input/output of optical waves. A first region of the optical coupler lies at a distance from the flared optical transitions. The first region includes a first recessed pattern. Second regions of the optical coupler lie between the first region and the flared optical transitions, respectively, in an adjoining relationship. The second regions include a second recessed pattern different from the first recessed pattern.

Abstract: Certain aspects of a novel weapon sight system combine a direct view, a visible light video view, and an infrared (IR) video view mode. Each of the view modes may be viewed individually or simultaneously with one or more of the other view modes through a single viewing aperture. Further, the one or more view-modes may be provided while providing a bore-sighted reticle superimposed on the selected view. Further, the reticle may be powered separately from the video view electronics enabling use of the reticle regardless of the power status video view electronics.

Abstract: A projection display device comprising a light source and an SBG device having a multiplicity of separate SBG elements sandwiched between transparent substrates to which transparent electrodes have been applied. The substrates function as a light guide. A least one transparent electrode comprises a plurality of independently switchable transparent electrode elements, each electrode element substantially overlaying a unique SBG element. Each SBG element encodes image information to be projected on an image surface. Light coupled into the light guide undergoes total internal reflection until diffracted out to the light guide by an activated SBG element. The SBG diffracts light out of the light guide to form an image region on an image surface when subjected to an applied voltage via said transparent electrodes.

Abstract: The present disclosure relates to a spectrometer arrangement for analyzing optical radiation from a light source comprising an echelle grating for dispersion of the radiation entering the spectrometer arrangement in a main dispersion direction, a dispersion element for dispersing the radiation in a cross-dispersion direction, the main dispersion direction and the cross-dispersion direction having a predeterminable angle to each other, and a detector unit for acquiring a first spectrum of a first part of the radiation comprising a first predeterminable wavelength range. According to the present disclosure, the spectrometer arrangement comprises a first optical element, which is arranged or configured in such a way that a second spectrum of a second part of the radiation comprising a second predeterminable wavelength range differing from the first can be acquired by means of the detector unit.

Abstract: Embodiments of the disclosure provide an integrated circuit (IC) structure, including an optical medium for light signals; and an optical grating coupler coupled to the optical medium. The optical grating coupler is configured to reorient light from the optical medium. A cladding material is over the optical grating coupler. An absorber layer is over the cladding material, and vertically above the optical grating coupler.

Abstract: Embodiments of the present disclosure provide a silicon-based optical antenna with a reflective layer and a preparation method therefor. The silicon-based optical antenna comprises: an SOI substrate, the SOI substrate at least comprises a bottom silicon layer, a buried oxide layer, and a top silicon layer, the buried oxide layer is located between the bottom silicon layer and the top silicon layer, the top silicon layer is etched to form a row of waveguides, spacings between the waveguides in the row of the waveguides are in an uneven distribution, each waveguide of the row of the waveguides is etched with gratings, the bottom silicon layer is formed with a groove directly reaching a surface of the buried oxide layer facing the bottom silicon layer, and the surface of the buried oxide layer in the groove is formed with a metal reflective layer.

Abstract: A Liquid Crystal Waveguide (LCW) system can provide sub-aperture incoupling or outcoupling of light having an input wavelength and input beamsize defining an aperture characteristic of the system. A Liquid Crystal Waveguide (LCW) can include a generally planar LCW core to receive light via a light input zone for communication toward a light output zone. Sub-aperture interfacial light couplers can be planarly arranged in or parallel to the planar LCW core in the light input zone or the light output zone. Sub-aperture interfacial light couplers can include teeth, prisms, or facets, a photonic crystal metasurface, or a geometric-phased holograph (GPH)). Overall LCW thickness can be reduced, which can be helpful in space-limited applications or for reducing material costs.

Abstract: A waveguide apparatus has in combination: a light pipe with an optical axis for guiding light therethrough; a light coupling element in optical contact with an elongate portion of the reflecting surface of the light guide; and an optical waveguide in optical contact with the coupling element.

Abstract: A plurality of tapered core waveguides which may be configured as a spectral component splitter, a spectral component combiner, and various combinations thereof, form a compact antenna array which may receive and/or transmit energy, act to form and steer a transmitted beam, act to discern received signals, and offer capability of multi frequency operation as well as controlled polarization.

Abstract: A grating coupler reflector (retro reflector) is formed within a photonics chip and includes a vertical scattering region, an optical waveguide, and a reflector. The optical waveguide is optically coupled to the vertical scattering region. The reflector is positioned at an end of the optical waveguide. The reflector is configured to reflect light that propagates through the optical waveguide from the vertical scattering region back toward the vertical scattering region. The location of the grating coupler reflector on the photonics chip is determinable by scanning a light emitting active optical fiber over the chip and detecting when light is reflected back into the active optical fiber from the grating coupler reflector. The determined location of the grating coupler reflector on the photonics chip is usable as a reference location for aligning optical fiber(s) to corresponding optical grating couplers on the photonics chip.

Abstract: A method of fabricating a waveguide device is disclosed. The method includes providing a substrate having an elector-interconnection region and a waveguide region and forming a patterned dielectric layer and a patterned redistribution layer (RDL) over the substrate in the electro-interconnection region. The method also includes bonding the patterned RDL to a vertical-cavity surface-emitting laser (VCSEL) through a bonding stack. A reflecting-mirror trench is formed in the substrate in the waveguide region, and a reflecting layer is formed over a reflecting-mirror region inside the waveguide region. The method further includes forming and patterning a bottom cladding layer in a wave-tunnel region inside the waveguide region and forming and patterning a core layer and a top cladding layer in the waveguide region.

Abstract: Disclosed are grating couplers having a high coupling efficiency for optical communications. In one embodiment, an apparatus for optical coupling is disclosed. The apparatus includes: a substrate; a grating coupler comprising a plurality of coupling gratings over the substrate, wherein each of the plurality of coupling gratings extends in a first lateral direction and has a cross-section having a middle-raised shape in a second lateral direction, wherein the first and second lateral directions are parallel to a surface of the substrate and perpendicular to each other in a grating plane; and a cladding layer comprising an optical medium, wherein the cladding layer is filled in over the grating coupler.

Abstract: A head-mounted display system is configured to project light to an eye of a user wearing the head-mounted display system to display content in a vision field of said user. The head-mounted display system comprises at least one diffusive optical element, at least one out-coupling optical element, at least one mask comprising at least one mask opening, at least one illumination in-coupling optical element configured to in-couple light from at least one illumination source into a light-guiding component, an image projector configured to in-couple an image and an at least one illumination source is configured to in-couple light into at least one illumination in-coupling optical element, an eyepiece, a curved light-guiding component, a light-guiding component comprising a portion of a frame, and/or two light-guiding components disposed on opposite sides of at least one out-coupling optical element.

Abstract: A temperature compensation module mounted in an arrayed waveguide grating (AWG) comprises a base attached to the AWG and a moving member attached to the base, wherein the base comprises: a first fixing part attached to a first sub chip of the AWG; a second fixing part attached to a second sub chip of the AWG; a hole which is a gap between the first fixing part and the second fixing part, and is disposed to include, within the gap, a cut surface for dividing the AWG into the first sub chip and the second sub chip; and a ‘’-shaped elastic part, wherein the moving member is attached to the first fixing part so as to horizontally move the first sub chip of the AWG in the direction of decreasing central wavelength changes caused by temperature changes.

Abstract: An image display apparatus includes a first waveguide, a second waveguide positioned at one side of the first waveguide, a first diffraction grating positioned at an other side of the first waveguide, a second diffraction grating positioned between the first waveguide and the second waveguide and a display engine configured to control a shape of the second diffraction grating according to a quantity of light diffracted from the first diffraction grating, wherein at least a portion of light incident on the first waveguide is diffracted from the first diffraction grating, and at least a portion of light incident on the second waveguide, is diffracted from the second diffraction grating.

Abstract: An optical wavelength dispersion device is disclosed, which includes a waveguide unit and an adjustable reflecting unit, wherein the waveguide unit has a first substrate, an input unit, a grating, a reflector and a second substrate. The input unit is formed on the first substrate and having a slit for receiving an optical signal, a grating is formed on the first substrate for producing an output beam once the optical signal is dispersed, the reflector is formed on the first substrate for reflecting the output beam, the second substrate is located on the input unit, the grating and the reflector, and forms a waveguide space with the first substrate; the adjustable reflecting unit is located outside of the waveguide unit, and is used for changing emitting angle and adjusting focus of the output beam.

Abstract: An apparatus is provided which comprises pressure pass-thru means, which includes: an optic fiber having a first end and a second end; a first connector coupled to the first end; a second connector coupled to the second end; a housing between the first and second ends, wherein the housing covers a portion of the optic fiber, wherein a portion of the optic fiber in the housing is bare; a filing material inside the housing; and a swaged gland fitting on the housing to secure the apparatus to a pressure boundary.

Abstract: An illumination device includes a solid waveguide; a plurality of light emitting diodes emitting light of different colors and arranged to project light into at least one of the surfaces of the waveguide; and one or more phosphor materials for converting light emitted by one of the LEDs from one color to another, such that an out-coupling region of the waveguide outputs a mixture of light from at least some of the LEDs and light converted by the phosphors materials.

Abstract: Planar waveguide junctions are described with a waggled transition section connecting input waveguide sections with output waveguides sections, in which the waggled transitions have alternating segments matching the input waveguide and output waveguides to efficiently transition the optical signal. The planar waveguide junctions can be used to form efficient optical splitters, mixers, or taps.

Abstract: Apparatus for generating a dynamic structured light pattern for optical tracking in three-dimensional space, comprises an array of lasers, such as a VCSEL laser array, to project light in a pattern into a three-dimensional space; and an optical element or elements arranged in cells. The cells are aligned with subsets of the laser array, and each cell individually applies a modulation, in particular an intensity modulation, to light from the laser or lasers of the subset, to provide a distinguishable and separately controllable part of the dynamic structured light pattern. A method of generating a structured light pattern is disclosed, in which light is provided from an array of lasers, and light is individually projected from subsets of the array of lasers to provide differentiated parts of the structured light pattern.

Abstract: A near-field light generator includes a plasmon generator including a plasmon exciting portion on which a surface plasmon is excited, and a near-field transducer including a front end face that generates near-field light from the surface plasmon. The near-field transducer is formed of a first metal material. The plasmon generator includes a first portion formed of the first metal material and a second portion formed of a second metal material. The first portion is in contact with the near-field transducer. The second portion includes at least part of the plasmon exciting portion.

Abstract: Examples of light projector systems for directing input light from a light source to a spatial light modulator are provided. For example, an optical device is disclosed which includes a first surface having a diffractive optical element, a second surface normal to the first surface, and a third surface arranged at an angle to the second surface. The third surface may be a beam splitting surface that is reflective to light of a first state and transmissive to light of a second state. The diffractive optical element may receive an input beam made up of light having the first state, and may convert the input beam into at least a first diffracted beam at a first diffraction angle such that the first diffracted beam is directed toward the second surface, is reflected by the second surface toward the third surface via total internal reflection, and is reflected by the third surface in a direction substantially parallel to the first surface.

Abstract: A photonic testing device includes a substrate, an optical device under test (DUT) disposed over the substrate, and an optical input circuit disposed over the substrate. The optical input circuit includes a first plurality of inputs each configured to transmit a respective optical test signal of a plurality of optical test signals. Each of the plurality of optical test signals includes a respective dominant wavelength of a plurality of dominant wavelengths. The optical input circuit further includes an output coupled to an input waveguide of the optical DUT. The output is configured to transmit a combined optical test signal comprising the plurality of optical test signals.

Abstract: A measurement device includes a sensing portion and a measuring portion. The sensing portion contains at least a fluorescent material whose emitting of fluorescent light ceases due to an action of a radioactive beam. The measuring portion measures a radiation quantity of the radioactive beam, with which the sensing portion is irradiated, based on an amount of decrease in the intensity of the fluorescent light emitted by the fluorescent material contained in the sensing portion when the radioactive beam acts on at least a portion of the fluorescent material. The fluorescent light is emitted due to irradiation of the fluorescent material by an excitation source.

Abstract: Devices, systems, reagents, and methods for the performance of multi-spectrum super resolution microscopy are disclosed.

Abstract: A transmission grating includes: first light-transmissive regions having a refractive index of n1; and second light-transmissive regions having a refractive index of n2 that is smaller than n1. Light-reflecting interfaces on which light transmitted through the first light-transmissive regions is incident are in parallel with one another and are inclined such that a line normal to each of light-reflecting interfaces is at an inclination angle ? with respect to the flat light-incident surface and to the flat light-emitting surface, wherein 0°<?<90°. When a thickness of the first light-transmissive regions in a direction perpendicular to the light-reflecting surfaces is t1 and a thickness of the second light-transmissive regions in a direction perpendicular to the light-reflecting surfaces is t2, the thickness t2, in ?m, is in a range of 0.1/?(n12?n22)1/2 to t1.