Abstract: Configurations for a tunable Echelle grating are disclosed. The tunable Echelle grating may include an output waveguide centered in a waveguide array, with input waveguides on both sides of the output waveguide. A metal tuning pad may be located over the slab waveguide and may be heated to induce a temperature change in the slab waveguide. By increasing the temperature of the propagation region of the slab waveguide, the index of refraction may shift, thus causing the peak wavelength of the channel to shift. This may result in an optical component capable of multiplexing multiple light sources in an energy efficient manner while maintaining a small form factor.

Abstract: The imaging lens consists of, in order from the object side, a front group, an aperture stop, and a rear group. The front group includes a diffractive optical element having a positive lens and a negative lens in order from the object side. A diffractive surface is provided between an object side surface of the positive lens and an image side surface of the negative lens. Assuming that a distance on an optical axis from the diffractive surface to the aperture stop in a state in which an object at infinity is in focus is Ddoe, and a focal length of the whole system in a state in which the object at infinity is in focus is f, the imaging lens satisfies Conditional Expression (1): 0.02<Ddoe/f<0.11.

Abstract: An optical device forming an outgoing electromagnetic wave from an incident electromagnetic wave comprises at least one unit cell (UC), comprising: at least two subwavelength optical elements (1, 2), each of them belonging to a different set (MSI, MS2) of subwavelength optical elements, a set of subwavelength optical elements being characterized by a type of optical response to an incident electromagnetic wave; means (21) enabling selective excitation of all subwavelength optical elements belonging to a given set, in response to an electromagnetic wave (20) incident on said unit cell.

Abstract: An ocular optical system configured to allow imaging rays from a display image to enter an observer's eye through the ocular optical system so as to form an image is provided. A direction toward the eye is an eye side, and a direction toward the display image is a display side. The ocular optical system includes a first lens element, a second lens element, and a third lens element arranged along an optical axis in sequence from the eye side to the display side. Each of the first to third lens elements has an eye-side surface and a display-side surface. The ocular optical system satisfies: 0<f/f1+f/f2+f/f3<0.35, where f is an effective focal length of the ocular optical system, f1 is a focal length of the first lens element, f2 is a focal length of the second lens element, and f3 is a focal length of the third lens element.

Abstract: A diffractive optical element includes a first lens having a convex surface, a second lens having a concave surface, disposed in such a manner that the concave surface of the second lens faces the convex surface of the first lens, and a diffraction grating section formed between the first and the second lenses and having positive optical power through diffraction. The diffraction grating section includes a first diffraction grating and a second diffraction grating disposed in this order from a side closer to the first lens; the second diffraction grating has a refractive index larger than that of the first diffraction grating, and an inner diameter of a grating wall surface of the diffraction grating section decreases as approaching to the second lens from the first lens.

Abstract: The present disclosure provides an ocular assembly. The ocular assembly including sequentially along an optical axis from an object side to an image side: a first lens with a positive refractive power has a convex object-side surface, and a second lens has a concave image-side surface, wherein at least one of the object-side surface of the first lens, an image-side surface of the first lens, an object-side surface of the second lens, and an image-side surface of the second lens is a Fresnel structure surface, wherein half of a maximal field-of-view HFOV of the ocular assembly satisfies: HFOV>40°, an axial distance TTL of the object-side surface of the first lens to the image plane and a total effective focal length f of the ocular assembly satisfy 1<TTL/f<1.5.

Abstract: Provided is an optical system including, in order from an object side to an image side, a front lens unit, an aperture stop, and a rear lens unit. The front lens unit consists of a positive lens and a diffractive optical element, which are arranged in order from the object side to the image side. The diffractive optical element consists of a plurality of lenses that are cemented to each other, and at least one of cemented surfaces of the plurality of lenses is a diffractive surface. An interval on an optical axis between the positive lens and the diffractive optical element is the largest among intervals on the optical axis between two lenses that are adjacent in the optical system.

Abstract: An image forming lens system includes a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, and a third lens unit. The first lens unit includes a front-side lens unit having a positive refractive power and a rear-side lens unit in order from the object side. The second lens unit moves at a time of focusing. The third lens unit includes a positive lens element. Each lens element in the front-side lens unit is a lens element that satisfies following Conditional Expression (a). The rear-side lens unit includes a negative lens element and a positive lens element. The front-side lens unit includes a diffractive lens component having a diffractive lens surface. The diffractive lens component has a positive refractive power. Following Conditional Expression (1) is satisfied: ?0.7?f/fLens??(a) 0.015??GFGR/f?0.25??(1).

Abstract: Mirrors, lenses, devices, apparatus, systems and methods for correcting temporal dispersion of laser pulses or other pulses of electromagnetic radiation in diffractive telescopes used in applications, such as but not limited to optical telescopes, transmitters, receivers, and transceivers for laser communication and imaging. Diffractive lenses and mirrors allow for producing large area telescopes and reducing or eliminating temporal dispersion of laser pulses and other pulses of electromagnetic radiation recorded by such telescopes. This can be achieved by utilizing high efficiency thin film diffractive optical films, particularly, diffractive waveplates, and having a secondary diffractive mirror of a shape selected to assure that the propagation time from the flat primary collecting lens or mirror is independent of the position on the flat primary collecting lens or mirror at which the radiation impinges.

Abstract: An optical system includes a diffractive surface and at least one aspherical surface, an aspherical surface of at least one aspherical surface closest to the diffractive surface is referred to as a first aspherical surface, a phase function ?(r) and an aspherical function X(r) of the first aspherical surface increase with different signs from each other in a height direction with increasing a distance from an optical axis, and a condition below is satisfied: - 0.10 ? ? i = 1 p ? ( Ci ? ( f / Fno ) 2 ? i - 1 ) / ? j = 1 q ? ( Aj ? ( f / Fno ) 2 ? j + 1 ) ? - 0.01 where f is a focal length of the optical system when focusing on an infinite object, and Fno is an F number of the optical system.

Abstract: A three-piece optical lens for capturing image and a three-piece optical module for capturing image, along the optical axis in order from an object side to an image side, include a first lens with positive refractive power, wherein an object-side surface thereof can be convex; a second lens with refractive power; and a third lens with refractive power, wherein both surfaces of each of the aforementioned lenses can be aspheric; the third lens can have positive refractive power, wherein an image-side surface thereof can be concave, and both surfaces thereof are aspheric; at least one surface of the third lens has an inflection point. The optical lens can increase aperture value and improve the imagining quality for use in compact cameras.

Abstract: A trenched-substrate based lens manufacturing method includes depositing lens material on a first side of a substrate, wherein the first side of the substrate has a plurality of trenches. The method further includes shaping a plurality of lens elements from the lens material. The method includes shaping the plurality of lens elements, on a respective plurality of surface portions of the first side, by contacting a mold to the first side. Each of the surface portions are adjacent a respective one of the trenches. Additionally, the method includes accommodating an excess portion of the lens material in the trenches. A lens system, manufactured using this method, includes a substrate with a planar surface and a trench embedded in the planar surface. The lens system further includes a lens element molded on the planar surface adjacent to the trench.

Abstract: The present disclosure relates to a lamp lens with a reduced chromatic aberration, and a lamp for a vehicle using the same. In the lamp lens with a reduced chromatic aberration, a thin film formed of a predetermined material is coated or deposited on a surface of the lamp lens and the thin film is formed within 30% of a diameter of the lamp lens above and below a center of the lamp lens, to increase a reflection of light in a specific wavelength band, thereby efficiently reducing a chromatic aberration.

Abstract: This optical system (100) comprises a prism (12) and a diffractive optical element (13). The prism (12) has a non-rotationally-symmetric aspheric surface for correcting eccentric aberration, and the diffractive optical element (13) includes a diffractive optical surface (DM) having a lattice structure that is as about an optical axis (Ax) of the optical system (100). The following condition is satisfied where ?Ne represents the refractive index difference of the diffractive optical surface (DM) in relation to the e-line (546.074 nm). 0.53>?Ne>0.

Abstract: Described are methods and apparatuses for manufacturing ultralong fiber Bragg gratings with arbitrary reflection wavelength. The method may include: generating two holographic beams entering a fiber with a certain intersection angle there-between from one side of the fiber and forming holographic interference fringes in the fiber, driving the two holographic beams to scan along the fiber by a motorized translation stage controlled by a computer; and adjusting the intersection angle between the two beams by motorized rotation stages or motorized mirror mounts controlled by the computer. The present disclosure can be applied in manufacturing ultralong fiber Bragg gratings with arbitrary reflection wavelength, such as narrow-reflection-band gratings, chirped gratings, and apodized gratings, etc.

Abstract: An optical system has a first relief-type diffraction grating fiducial, or alignment mark, on a transparent surface of a first optical wafer or plate, the grating arranged to deflect light away from an optical path and appear black. The first wafer may have lenses. The first fiducial is aligned to another fiducial on a second wafer having further optical devices as part of system assembly; or the fiducials are aligned to alignment marks or fiducials on an underlying photosensor. Once the optical devices are aligned and the wafers bonded, they are diced to provide aligned optical structures for a completed camera system. Alternatively, an optical wafer is made by aligning a second relief-type diffraction grating fiducial on a first master to a first relief-type diffraction grating fiducial on an optical wafer preform, pressing the first master into a blob to form optical shapes and adhere the blob to the optical wafer preform.

Abstract: A projection display 210 arranged to display an image to an observer 212 use waveguide techniques to generate a display defining a large exit pupil at the point of the observer 212 and a large field of view, while using a small image-providing light source device. The projection display 210 uses two parallel waveguides 214, 216 made from a light transmissive material. One waveguide 214 stretches the horizontal pupil of the final display and the other waveguide 216 stretches the vertical pupil of the final display and acts as a combiner through which the observer 212 views an outside world scene 220 and the image overlaid on the scene 220. In a color display, each primary color is transmitted within a separate channel R, G, B.

Abstract: The invention discloses a lens, which comprises an outer surface and an inner surface, wherein a pattern outline is printed on the outer surface; and an argon gas layer, a high refractive index layer, a lower refractive index layer and a waterproof layer are evaporated at an area, outside the pattern outline, of the outer surface from inside to outside in turn. By adoption of clear patterns formed on the outer surface by the manufacturing processes and a four-layer vacuum electroplating film evaporated at an area, outside the pattern outline, of the outer surface, the coating does not block the sight and the lens is more beautiful and has the functions of radiation resistance and ultraviolet resistance. The invention also discloses a pattern printing and vacuum electroplating method which has simple and efficient processes and realizes the functions of the coated lens.

Abstract: A microstructure manufacturing method includes: preparing a mold having on a front side thereof a plurality of fine structures, with conductivity being imparted to a bottom portion between the plurality of fine structures; forming a first plating layer between the plurality of fine structures by plating the bottom portion; and forming a second plating layer of larger stress than the first plating layer on the first plating layer between the plurality of fine structures, wherein the stress of the second plating layer is used to curve a back side surface of the mold.

Abstract: An extended depth of field three-dimensional nano-resolution imaging method includes: creating an optical module with a double helix point spread function and multi-stage imaging properties of a defocus optical grating; obtaining double helix image of a molecule by imaging a molecule using the optical module; determining a lateral position of the molecule according to a position of a midpoint of double helix sidelobes on the imaging plane in the double helix image; determining an axial position of the molecule according to a rotation angle of a line of centers of the double helix sidelobes on the imaging plane and the position of the midpoint of the double helix sidelobes on the imaging plane in the double helix image. The double helix point spread function and the defocus optical grating multi-stage imaging are combined to implement three-dimensional imaging to extended the depth of field and to improve the resolution.

Abstract: An optical de-multiplexer (de-MUX) that includes an optical device that images and diffracts an optical signal using a reflective geometry is described, where a free spectral range (FSR) of the optical device associated with a given diffraction order abuts FSRs associated with adjacent diffraction orders. Moreover, the channel spacings within diffraction orders and between adjacent diffraction orders are equal to the predefined channel spacing associated with the optical signal. As a consequence, the optical device has a comb-filter output spectrum, which reduces a tuning energy of the optical device by eliminating spectral gaps between diffraction orders of the optical device.

Abstract: A concave diffraction grating for integrated optics is constructed by replacing the reflective metallic part by either multiple thin elements of metal or multiple elements of dielectric material, each partially reflecting the light, and arranged on elliptical fashion in order to distribute the diffraction/reflection of light and provide aberration-free focusing, by combining diffraction condition and Bragg condition of these curved reflectors.

Abstract: A molded part prepared by a mold transfer method using a die, including a surface which includes a slope, wherein a direction of a normal line of the slope is different from a die releasing direction; and a pattern which is formed on the surface and which includes grooves located on a portion of the slope so as to extend along the slope in the slanting direction of the slope. An optical element, which has an anti reflection function, including the molded part mentioned above, wherein the interval between two adjacent grooves is not greater than the wavelength of light irradiating the optical element. An optical device including a light source configured to emit light; and the optical element mentioned above which processes the light emitted by the light source.

Abstract: Described herein are diffraction gratings and methods for the manufacture thereof. One method comprises applying a force to a substrate to strain the substrate, disposing a thin film on at least a portion of the substrate, and reducing the force applied to the substrate, thereby causing the thin film to buckle.

Abstract: Objects are to obtain a highly accurate diffraction element that may prevent an intensity decrease of a light beam entering a light receiving unit without a decrease in diffraction efficiency and without a problem of flare or the like, a manufacturing method for the diffraction element, and a spectrometer using the same. A diffraction element (2) includes a diffraction grating formed on a substrate having a curved surface. In the diffraction element (2), the curved surface (3) has an anamorphic shape formed by pivoting a curved line (I) in a plane about a straight line (II) in the same plane serving as a rotation axis, and gratings (10a) of the diffraction grating (10) exist in cross sections orthogonal to the rotation axis.

Abstract: An optical source uses feedback to maintain a substantially fixed spacing between adjacent wavelengths in a set of wavelengths in a wavelength comb output by the optical source. In particular, a set of light sources in the optical source provide optical signals having the set of wavelengths. Moreover, the optical signals are output at diffraction angles of an optical device in the optical source (such as an echelle grating), and optical detectors in the optical source determine optical metrics associated with the optical signals. Furthermore, control logic in the optical source provides control signals to the set of light sources based on the determined optical metrics.

Abstract: An optical system comprising an input member, a predetermined output plane and a reflection type diffraction grating is disclosed. The input member receives an optical signal. The reflection type diffraction grating comprises a grating profile curved surface and a plurality of diffraction structures. The diffraction structures, which separate the optical signal into a plurality of spectral components, are respectively disposed on the grating profile curved surface by a plurality of pitches. At least some pitches are different from each other, so that the spectral components are emitted to the predetermined output plane in a direction substantially perpendicular to the predetermined output plane. The grating profile curved surface is used for focusing the spectral components on the predetermined output plane.

Abstract: There is provided a spectrometric optical system, comprising a reflection member having a concave surface formed along a first circle, a diffraction grating having an edge part and a convex surface formed along a second circle disposed concentrically with the first circle, on which the light reflected at the concave surface of the reflection member is incident, and an input element disposed at a predetermined position to the reflection member and the diffraction grating such that a diffracted light, emitted from the diffraction grating, having a wavelength region of not less than 600 nm to not more than 1100 nm, and reflected at the concave surface, passes between the input light input to the spectrometric optical system and the edge part of the diffraction grating.

Abstract: An objective lens element having excellent compatibility with optical discs having different base material thicknesses is provided. The objective lens element has optically functional surfaces on an incident side and an exit side. At least either one of the optically functional surfaces on the incident side and the exit side includes a diffraction portion which satisfies at least either one of the following formulas (1) and (2): ?1×?2<0 (“×” represents multiplication)??(1), (sin ?2)/?2=?(sin ?1)/?1??(2), where ?1 is the diffraction angle of a light beam having a diffraction order providing the maximum diffraction efficiency at the wavelength ?1, and ?2 is the diffraction angle of a light beam having a diffraction order providing the maximum diffraction efficiency at the wavelength ?2.

Abstract: An optical arrangement includes a light source which emits coherent light of a wavelength ?, and a diffraction grating which has a multiplicity of diffraction structures which follow one another periodically at the spacing of a grating period d and are arranged along a base surface, the individual diffraction structures respectively having a blaze flank and an antiblaze flank, the blaze flanks being arranged at an angle ? and the antiblaze flanks being arranged at an angle ? to the base surface, and respectively neighbouring blaze and antiblaze flanks enclosing an apex angle ?, and an incident light beam being arranged at a Littrow angle ?L relative to a grating normal of the diffraction grating.

Abstract: A diffractive lens 11 that includes: a lens base 18, which has a second surface 13 with first and second groups of diffraction grating portions 20 and 21; and a protective coating 17, which is arranged on the first group of diffraction grating portions 20. The first group of diffraction grating portions 20 has a first group of diffraction steps and the second group of diffraction grating portions 21 has a second group of diffraction steps, which is lower in height than the first group of diffraction steps. One of the respective materials of the base 18 and the protective coating 17 has a higher refractive index and a greater Abbe number than the other material. And the second group of diffraction steps is not covered with the protective coating 17.

Abstract: An optical scanning apparatus includes a semiconductor laser and a first optical element that are fixed on a single continuous member. A second optical element, which is a diffraction optical element, has a diffracting surface in which a plurality of elliptical grooves is formed and which includes a diffracting portion power such that a change in the beam waist position in a main scan direction and a sub-scan direction due to temperature variation in the optical scanning apparatus becomes substantially zero. The member on which the semiconductor laser and the first optical element are fixed has a linear coefficient of expansion such that the change in the beam waist position becomes substantially zero even when there is temperature variation.

Abstract: An optical de-multiplexer (de-MUX) that includes an optical device that images and diffracts an optical signal using a reflective geometry is described, where a free spectral range (FSR) of the optical device associated with a given diffraction order abuts FSRs associated with adjacent diffraction orders. Moreover, the channel spacings within diffraction orders and between adjacent diffraction orders are equal to the predefined channel spacing associated with the optical signal. As a consequence, the optical device has a comb-filter output spectrum, which reduces a tuning energy of the optical device by eliminating spectral gaps between diffraction orders of the optical device.

Abstract: An element includes a first resin layer and a second resin layer disposed between a first glass lens substrate and a second glass lens substrate, a boundary surface between the first resin layer and the second resin layer having a diffraction grating shape including a plurality of inclined surfaces and wall surfaces. The second resin layer is composed of a fluororesin in which fine metal oxide particles are dispersed. Since a refractive index distribution easily occurs in this material during curing by application of ultraviolet light, by applying ultraviolet light substantially perpendicular to the inclined surfaces of the diffraction grating shape, a refractive index distribution is formed in the thickness direction perpendicularly to the inclined surfaces.

Abstract: A plastic lens includes a flange portion on an outer circumference of a lens effective-diameter portion and manufactured by injecting a resin into a mold via a gate portion. The plastic lens is characterized by having a shape satisfying conditions of s/t?0.61 and E.D/D?0.4 when s [mm] and t [mm] represent a peripheral thickness, a central thickness of the lens effective-diameter portion, E.D [mm] represents a lens effective diameter, and D [mm] represents a lens diameter.

Abstract: A light pipe that can be employed for a Concentrator Photo-Voltaic (CPV) system is provided. The light pipe homogenizes light by diffusion and/or refraction, and can be embodied in a structure that has a low aspect ratio. The diffusion and/or refraction can be effected by concave or convex surfaces of a transparent medium that forms a body of the light pipe, by light diffracting particles, and/or by a diffracting surface. Optionally, multiple transparent media can be employed with a refracting and/or diffracting interface therebetween. The reduced aspect ratio of the light pipe can improve reliability of mechanical alignment in the CPV system as well as reducing the cost of manufacturing and/or aligning the light pipe within the CPV system.

Abstract: A diffraction grating lens according to the present invention includes a lens body and a diffraction grating provided on the surface of the lens body, the diffraction grating including a plurality of annular zones having slopes inclined along a width direction and a plurality of step surfaces respectively located between the plurality of annular zones. At least one of the plurality of annular zones is light-transmissive across its entire area along the width direction, and in the at least one annular zone, a light transmittance near at least one of two ends along the width direction is smaller than a light transmittance near a central portion along the width direction.

Abstract: An optical system has a lens assembly for imaging an object. The lens assembly includes a lens wherein at least a portion of a peripheral part of the lens includes a diffraction grating arranged to divert light arriving on the peripheral part of the lens from an object. The diffraction grating diverts the light away from a focal region, where a central part of the lens focuses light arriving on the central part of the lens from the object, into an image of the object.

Abstract: A diffraction grating lens according to the present invention includes a lens body 171, and a diffraction grating which has been formed on the surface of the lens body 171 and which includes diffraction steps and concentric annular zones. Each annular zone is interposed between two adjacent ones of the diffraction steps. The lens body 171 is made of a first material that has a refractive index n1 (?) at an operating wavelength ?. The diffraction grating is in contact with the air. At least one of the annular zones has one of a recess 11 and a protrusion 12 provided for at least a part of the inner end portion thereof and the other provided for at least a part of the outer end portion thereof, respectively. The diffraction grating lens satisfies the relation 0.9 ? d ? m · ? n 1 ? ( ? ) - 1 ? 1.1 ? d where d represents a designed step length of the diffraction step 14 and m represents an order of diffraction.

Abstract: A telephoto lens TL having, in order from an object, a plurality of lenses L1, L2, . . . and a diffractive optical element DOE which has a diffraction grating having a rotationally symmetric shape with respect to the optical axis, wherein the diffractive optical element DOE is disposed on any one of lens surfaces of the plurality of lenses L1, L2, . . . , and conditional expression 0.50<fa/Rd<0.90 or 1.10<fa/Rd<2.00 is satisfied, where fa denotes a combined focal length of each lens from the lens L1, which is closest to the object, of the plurality of lenses L1, L2, . . . to the lens L2, on which the diffractive optical element DOE is disposed, and Rd is a radius of curvature of the lens surface on which the diffractive optical element DOE is disposed.

Abstract: A method for producing a fine structure includes: (a) forming a photosensitive film to cover a plurality of first convex portions formed in at least one surface of a substrate; (b) arranging liquid to cover the photosensitive film on the at least one surface of the substrate; (c) arranging a transparent parallel plate such that the parallel plate opposes the substrate via the liquid; (d) generating interference field by a laser beam to irradiate the interference field onto the photosensitive film via the parallel plate and the liquid; (e) removing the liquid and the parallel plate to develop the photosensitive film so as to form a photosensitive film pattern; and (f) etching the substrate using a mask of the photosensitive film pattern to form a plurality of fine convex portions smaller than the first convex portions on the at least one surface of the substrate.

Abstract: A multifocal lens device is disclosed. The device comprises a lens body being formed with a plurality of concentric annular zones separated by slanted steps. The concentric zones effect both diffraction and refraction of incident light, while the steps are substantially devoid of any diffractive or refractive power.

Abstract: A small shooting lens has high optical performance and is suitable for mass production. To attain this, the shooting lens includes at least three lens groups disposed in order from an object side, wherein an adhesion multiple-layer diffractive optical element is formed on one of surfaces disposed between an object surface and an imaging plane, and a maximum image height Y and an entire length L satisfy 0.1<Y/L<3.0 . . . (1). Thus using the multiple-layer diffractive optical element in the shooting lens makes it possible to improve diffraction efficiency over a wide range and reduce flare. Particularly, the multiple-layer diffractive optical element has a merit that its production and assembling are easy. Further, according to the conditional expression (1), it is possible to realize the downsizing of the shooting lens while also maintaining its imaging quality.

Abstract: A diffractive lens according to the present invention has the function of focusing light. The diffractive lens has a side on which a diffraction grating is arranged on either an aspheric surface or a spherical surface in its effective area. The diffraction grating has n0 phase steps, which are arranged concentrically around the optical axis of the diffractive lens. And the radius rn of the circle formed by an nth one (where n is an integer that falls within the range of 0 through n0) of the phase steps as counted from the optical axis of the diffractive lens satisfies rn=?{square root over (a{(n+c+dn)?b(n+c+dn)m})}{square root over (a{(n+c+dn)?b(n+c+dn)m})} where a, b, c and m are constants that satisfy a>0, 0?c<1, m>1, and 0.05 ? b 0 < b < b 0 b 0 = 1 mn 0 m - 1 and dn is an arbitrary value that satisfies ?0.25<dn<0.25.

Abstract: The optical system includes plural lens groups, a negative lens included in one lens group among the plural lens groups and formed of a first medium, a diffractive grating formed on at least one lens surface of the negative lens and being in contact with a second medium different from the first medium, and a positive lens included in the one lens group and formed of a third medium different from the first medium and the second medium. The first medium satisfies ndA?1.7 and 40??dA?55 where ndA represents a refractive index of the first medium for a d-line, and ?dA represents an Abbe number of the first medium for the d-line. The third medium satisfies ndC?1.55 and ?dC?60 where ndC represents a refractive index of the third medium for the d-line, and ?dC represents an Abbe number of the third medium for the d-line.

Abstract: [Problems] A higher forgery prevention effect is realized. [Means for Solving Problems] A display according to the present invention is characterized by includes a relief-structured region as an image-constituting element including recessed portions, protruding portions or both of them arranged two-dimensionally on one of main surfaces of a light-transmitting layer, and a reflection layer supported by the one of the main surfaces and covering at least a part of the relief-structured region, wherein a center-to-center distance of the recessed portions, protruding portions or both of them falls within a range of 200 nm to 500 nm. Further, it is characterized in that it comprises multiple relief-structured regions, and a shape, depth or height, the center-to-center distance and an arrangement pattern of the recessed portions, protruding portions or both of them in at least one of the relief-structured regions are different from those in other relief-structured region(s).

Abstract: A phase grating includes a substrate and a first dielectric layer. The first dielectric layer is disposed on the substrate and includes a column and a plurality of rings. The top sides of the column and the top sides of the rings align with one another to form a flat plane. The column and the rings are concentric.

Abstract: Provided is a lens having a high NA, wherein defects caused when the lens is molded can be eliminated and the laps exhibits a high mountability. A transition surface transferring surface (31b) is formed between a first optical surface transferring surface (31a) and an intermediate end surface transferring surface (31c) to form a transition surface. Consequently, if a lens (OE) has a large thickness deviation ratio, the occurrence of a flow mark, etc., is prevented in order to achieve a high precision molding of the lens.

Abstract: When a substrate is curved cylindrically, stress concentrates along a stress concentration line on the substrate. First to fourth sub-diffraction gratings are arranged on the substrate such that the stress concentration line overlaps one of the sub-diffraction gratings. This reinforces the substrate to improve its stiffness along the stress concentration line and thus prevents the damage to the substrate along the stress concentration line. Additionally, for example, the first to fourth sub-diffraction gratings are arranged on the substrate such that a gap between the first and second sub-diffraction gratings is out of alignment with a gap between the third and fourth sub-diffraction gratings in a direction of the stress concentration line. This also reinforces the substrate and prevents the damage to the substrate along a line or a portion other than the stress concentration line.

Abstract: The present invention reduces the angle dependence of diffraction efficiency by taking the diffraction pitch and diffraction step of an optical element with a diffraction grating such as a lens into account. Specifically, for that purpose, an optical element that has a first group of diffraction grating portions 20 around an optical axis 10 is covered with a protective coating 14, and a second group of diffraction grating portions 21 are arranged on the surface of the protective coating 14 far away from the optical axis 10.