Abstract: A surface pattern (18) is in the form of a visually visible mosaic comprising a number of surface portions (8; 9; 15; 16; 17) and is embedded in a laminate (1) comprising at least a transparent cover layer (2) and a protective layer (5). The surface portions (8; 9; 15; 16; 17) are transparent, scatter or reflect incident light (10) or diffract the incident light (10) at microscopic relief structures (4). The surface portions (8; 9; 15; 16; 17) are at least partially covered with a reflection layer (3). At least one of the surface portions occupied by a microscopic relief structure (4), an area (16), is a ZOM-structure (4?) with a predeterminedly slowly varying profile height h and a spatial frequency f, wherein the product of a predetermined limit wavelength ?G of the visible spectrum and the spatial frequency f is greater than or equal to one.

Abstract: A diffraction grating for optical communication is disclosed. The diffraction grating includes a substrate and a reflective material adjacent the substrate, wherein one or more input optical signals incident the reflective material is diffracted into one or more output optical signals over a wavelength range of at least approximately 30 nm, within which the diffraction grating is substantially polarization insensitive.

Abstract: Method and apparatus are contemplated for receiving from an input, an optical signal in a volume hologram comprising a transfer function that may comprise temporal or spectral information, and spatial transformation information; diffracting the optical signal; and transmitting the diffracted optical signal to an output. A plurality of inputs and outputs may be coupled to the volume hologram. The transformation may be a linear superposition of transforms, with each transform acting on an input signal or on a component of an input signal. Each transform may act to focus one or more input signals to one or more output ports. A volume hologram may be made by various techniques, and from various materials. A transform function may be calculated by simulating the collision of a design input signal with a design output signal.

Abstract: A diffractive optical element having a design wavelength ?, includes a diffractive surface for diffracting predetermined light corresponding to the design wavelength, and a mark shaped so that, with regard to the predetermined light, a phase difference corresponding to a multiple, by an integer, of the design wavelength ? is produced between (i) a light ray, of the predetermined light, as transmitted through or reflected by the mark and (ii) a light ray, of the predetermined light, as transmitted through or reflected by a portion adjacent to the mark, and that, with regard to second light of a second wavelength ?? different from the design wavelength ?, no phase difference corresponding to a multiple, by an integer, of the second wavelength ? is produced between (a) a light ray, of the second light, as transmitted through or reflected by the mark and (b) a light ray, of the second light, as transmitted through or reflected by a portion adjacent to the mark.

Abstract: A tunable optical device for adding or dropping one or more channels in a wavelength division multiplexing communication system is disclosed. The tunable optical device comprises one or more filters, wherein at least one filter comprises (a) one or more elastimers and (b) one or more gratings. An elastimer is a polymer that expands and contracts with a change in a voltage applied across the polymer or when a certain wavelength of light is diffracted from or transmitted through the polymer.

Abstract: A plane diffraction grating based on surface normal rotation according to the present invention is designed so that the profile of the grooves at a radial area is determined depending on a rotational position of the area about a rotational center defined as a foot of the rotational axis on the surface of the plane diffraction grating. An optical system such as a spectrometer or a monochromator according to the present invention uses such a plane diffraction grating, and requires a special arrangement. The optical system includes: a plane diffraction grating as described above; a mechanism for rotating the plane diffraction grating about the rotational axis; an incidence optical system for casting a converging beam of light on a point of the surface of the plane diffraction grating, where the point is set apart from the rotational center.

Abstract: Optical articles, including light management films, prepared from brominated polycarbonate material are disclosed. The brominated polycarbonate provides a film exhibiting good light transmittance, high refractive index, good flame resistance, and good mechanical properties.

Abstract: A reflection type diffraction grating according to the present invention has a structure in which a metal film as a first layer with reflectance not lower than 30% with respect to the wavelength of incident light and a transparent dielectric film as a second layer are laminated successively on the surface of the reflection type diffraction grating. With respect to the wavelength of incident light, the metal film has a refractive index selected to be not higher than 1.5 and an extinction coefficient selected to be not smaller than 6.0. The transparent dielectric film has a refractive index selected to be in a range of from 1.30 to 1.46, both inclusively, with respect to the wavelength of incident light and has an optical film thickness selected to be in a range of from 0.20? to 0.38?, both inclusively, when ? is the wavelength of incident light.

Abstract: A relief type diffraction optical element including a substrate made of an optical material, said substrate having formed on its surface a non-even width relief pattern which include a first zone group consisting of at least one zone whose cross sectional configuration is formed by a curvilinear portion which follows a phase shift function or at least two rectilinear portions which approximates the phase shift function, and a second zone group consisting of a plurality of zones each having a single rectilinear portion approximating the phase shift function.

Abstract: A diffractive optical element including a stack of first, second and third optical regions or a stack of first, second, third and fourth optical regions, a first relief pattern formed between the first and second optical regions, and a second relief patterns formed between the second and third or between the third and fourth optical regions. The first and second relief patterns have substantially identical pitch distributions and are substantially aligned in a direction of an optical axis. Depths of the first and second relief patterns are set such that a wavelength dependency of diffraction efficiency can be decreased over a wavelength range to be used. It is possible to manufacture in a simple manner at a low cost a diffractive optical element in which undesired flare and ghost are suppressed.

Abstract: A method of simultaneously reading out squared components of a vector represented by a plurality of holographic gratings comprising the steps of generating a reference wave of known amplitude and diffracting the reference wave from each holographic grating to produce a plurality of diffracted waves each of which has an intensity proportional to the square of a component of the vector. The method allows squared components of the vector to be read out in parallel increasing the speed at which they may be processed compared to standard electronic techniques.

Abstract: A diffractive optical element includes a substrate having a surface relief pattern formed on a first side thereof. The diffractive optical element includes an anti-reflection coating formed on the surface relief pattern, thereby forming a coated surface relief pattern with substantially the same dimensions as the surface relief pattern formed on the substrate.

Abstract: A diffractive optical element efficiently converts an input light beam into an output light beam having a specified cross-sectional shape. The diffractive optical element includes a plurality of partial optical elements. The plurality of partial optical elements convert the input light beam to respective partial light beams, each of which has a shape that does not correspond to the specified cross-sectional shape. The sum of the partial light beams matches the shape of the output light beam (i.e., having the specified cross-sectional shape).

Abstract: A diffractive optical element includes a first layer having a relief-type grating, a second layer having a relief-type grating, and a third layer having a relief-type grating. The first, second and third layers are formed of different materials. The diffractive optical element has at least three diffraction optical parts in the boundary areas of the respective layers. The diffractive optical element is set so that at least wavelengths, the diffraction efficiency thereof for diffracted light of a predetermined order may be maximum. The three wavelengths are substantially coincident with the main wavelengths of the three primary colors.

Abstract: A projection optical system includes at least one lens, at least one concave mirror, at least one diffractive optical element, a first imaging optical system that includes the at least one lens and the at least one concave mirror, for imaging an intermediate image of an object, a second imaging optical system, having the at least one lens and the at least one diffractive optical element, for projecting the intermediate image onto an image plane, and a field optical system disposed between the first and second imaging optical systems.

Abstract: An optical system for forming an image of an object. The optical system includes an optical element, which is deformed by the weight thereof, and at least one optical member for preventing a change in optical performance of the optical system due to deformation of the optical element, when the optical element is provided in the optical system.

Abstract: A distributed optical structure comprises a set of diffractive elements. Individual diffractive element transfer functions collectively yield an overall transfer function between entrance and exit ports. Diffractive elements are defined relative to virtual contours and include diffracting region(s) altered to diffract, reflect, and/or scatter incident optical fields (altered index, surface, etc). Element and/or overall set transfer functions (amplitude and/or phase) are determined by: longitudinal and/or angular displacement of diffracting region(s) relative to a virtual contour (facet-displacement grayscale); longitudinal displacement of diffractive elements relative to a virtual contour (element-displacement grayscale); and/or virtual contour(s) lacking a diffractive element (proportional-line-density gray scale).

Abstract: A label (1) comprising a layer composite (15) includes at least one machine-readable diffractive bar code (3) consisting of narrow rectangular fields (4) occupied by the optically active structures and intermediate surfaces (5). The optically active structures which are covered by a reflection layer are embedded between layers of the layer composite (15). The diffractive relief structure used in the diffractive bar code (3) for the fields (4) diffracts and polarizes incident light and scatters the diffracted light into a half-space above the diffractive relief structure. A second diffractive relief structure differs at least in respect of the polarization of the polarizedly backscattered light with respect to the first diffractive relief structure. The second diffractive relief structure can be used for example for field surfaces of a second bar code in the bar code field (9) on the label (1) or for the intermediate surfaces (5).

Abstract: An optical system includes a diffractive optical element having a diffraction grating provided, on a lens surface having a curvature, in a concentric-circles shape rotationally-symmetrical with respect to an optical axis. The sign of the curvature of the lens surface having the diffraction grating provided thereon is the same as the sign of a focal length, at a design wavelength, of a system composed of, in the optical system, a surface disposed nearest to an object side to a surface disposed immediately before the lens surface having the diffraction grating provided thereon, and is different from the sign of the distance from the optical axis to a position where the center ray of an off-axial light flux enters the lens surface having the diffraction grating provided thereon. Further, the apex of an imaginary cone formed by extending a non-effective surface of the diffraction grating is located adjacent to the center of curvature of the lens surface having the diffraction grating provided thereon.

Abstract: Novel methods are disclosed for designing and constructing miniature optical systems and devices employing light diffractive optical elements (DOEs) for modifying the size and shape of laser beams produced from a commercial-grade laser diodes, over an extended range hitherto unachievable using conventional techniques. The systems and devices of the present invention have uses in a wide range of applications, including laser scanning, optical-based information storage, medical and analytical instrumentation, and the like. In the illustrative embodiments, various techniques are disclosed for implementing the DOEs as holographic optical elements (HOEs), computer-generated holograms (CGHs), as well as other diffractive optical elements.

Abstract: An optical identification element 8 includes an optical substrate 10 having at least one diffraction grating 12 disposed therein. The grating 12 has a one or more of colocated pitches A which represent a unique identification N bit digital code that is detected when illuminated by incident light 24. The incident light 24 may be directed transversely onto the side or onto an end of the substrate 10 with a narrow band (single wavelength) or multiple wavelength source, in which case the code is represented by a spatial distribution of light or a wavelength spectrum, respectively. The element 8 can provide a large number of unique codes, e.g., greater than 67 million codes, and can withstand harsh environments. The element 8 can be used in any application that requires sorting, tagging, tracking or identification, and can be made on a micron scale “microbeads” if desired, or larger “macro-elements” for larger applications. The code may be digital binary or may be other numerical bases.

Abstract: A diffraction element includes a light-transmittable member and a diffraction grating formed on at least one face of the light-transmittable member. When a first laser beam having a first wavelength &lgr;1 and a second laser beam having a second wavelength &lgr;2 are transmitted through the diffraction element at first and second diffraction efficiencies, respectively, the diffraction element functions to equalize the first and second diffraction efficiencies to each other by only the one face of the diffraction element. The diffraction grating has a first phase modulation amount ø1 for the first laser beam and a second phase modulation amount ø2 for the second laser beam and the first and second phase modulation amounts ø1 and ø2 are, respectively, approximate to (2&pgr;N1±&Dgr;ø) and (2&pgr;N2±&Dgr;ø) in which “N1” and “N2” are natural numbers and “&Dgr;ø” is a phase variation amount.

Abstract: An optical system provides high-contrast operation by collecting zero order light. The optical system comprises a light modulator and a collector. The light modulator is preferably a grating light valve™ light modulator including a plurality of elements selectively operable in a first mode and a second mode, wherein a gap between adjacent elements is equal to or less than a wavelength of an incident light beam. The plurality of elements in the first mode reflect light along a return path, where the plurality of elements in the second mode direct light away from the return path. The collector is coupled to the light modulator to collect zero order light along the return path while the plurality of elements are in the first mode and to collect zero order light along the return path while the plurality of elements are in the second mode.

Abstract: A diffractive optical element has a diffraction grating formed by periodic depressions and projections on the surface of a substrate and a dielectric multilayer film on the diffraction grating. The materials of the respective layers of the film are chosen such that the depth of the depressions is an integral multiple of the sum of the thickness of the layers in one period of the film. As a result, individual layers of the film are continuous across multiple depressions and projections, to provide improved first-order reflectance.

Abstract: Integrated semiconductor waveguide gratings, methods of manufacture thereof and methods of apodizing thereof are described. A semiconductor waveguide grating includes a substrate, a cladding layer disposed on the substrate, a guide structure that includes a plurality of discrete transverse sections implanted with ions disposed between adjacent transverse sections substantially free of implanted ions.

Abstract: A pitch averaging Bragg grating includes a plurality of grating peaks spaced by different pitch values. By selecting the different pitch values to have an average pitch value equal to a target pitch value, the pitch averaging Bragg grating can be made to perform like a constant pitch Bragg grating having a fixed pitch at the target pitch value. The different pitch values can be multiples of the minimum placement resolution of a production tool to be used to produce the Bragg grating. The pitch averaging Bragg grating can be used in place of constant pitch Bragg gratings in optical devices and systems, such as DFB lasers, DBR lasers, optical spectral filters, multi-wavelength laser arrays, and WDM systems.

Abstract: The invention is directed to metal-free grating for use in wavelength optical communications, and in particular to metal-free, reflective immersed diffraction gratings. The gratings of the invention area made of at least a first material 1 of refractive index n1 and a second material of refractive index n2. Materials 1 and 2 must obey the Expressions: (I) n1>n2, (II) n1>&lgr;/2L>n2 for single diffracted order at Littrow, and (III) n2/n1<Sin|&thgr;j|<1; wherein &lgr; is the wavelength of the light incident on the grating, &thgr;j represents any and all propagation angles of incident and diffracted light, and L is the grating period. The grating profile is located at the interface of material 1 and to material 2. In one embodiment, the grating profile is made from additional material 3 and 4 of refractive index n3 and n4, respectively, and is placed between materials 1 and 2. In another embodiment the grating is made from silicon.

Abstract: A diffractive element used in conjunction with a grating to move a desired order beam off-axis, thereby reducing interference by undesired orders. Use of the off-axis grating allows a more uniform beam in the presence of manufacturing defects, such as etch depth errors. The diffractive element used with the off-axis grating may include a beam shaper, a one-dimensional beam splitter, or a two-dimensional beam splitter.

Abstract: A diffraction grating and devices employing same are disclosed. In one particular exemplary embodiment, the present invention may be realized as a diffraction grating comprising a reflective material having a blazed surface with a blaze angle between about 33 degrees and about 41 degrees, and an optically transmissive material disposed adjacent the reflective material having an index of refraction (n), wherein the blazed surface of the reflective material has approximately (350±30)*n number of grooves per millimeter.

Abstract: A 2D diffraction grating light valve modulates an incident beam of light. A plurality of elements each have a reflective surface with their respective reflective surfaces substantially coplanar. Alternatively, the reflective surfaces of the plurality of elements lie within one or more parallel planes. The elements are supported in relation to one another. Preferably, a planar member includes a plurality of holes arranged in a symmetrical two-dimensional array and configured such that the holes substantially optically extend the elements. Alternatively, one or more elements substantially optically extends the plurality of holes. The planar member includes a light reflective planar surface that is parallel to the plane of the elements within a functional area of the device. The planar member is supported in relation to the elements. By applying an appropriate biasing voltage to the planar member, the planar member can be moved in a direction normal to the plane of the elements.

Abstract: The present invention relates to a prism diffuser for diffracting and spreading light, and in particular to a prism diffuser for diffracting and spreading light which is capable of spreading light in a certain direction at a wider angle based on a structure combined with a prism capable of diffracting light on a surface of a medium formed of a glass which transmits or reflect light, a film formed of a transparent synthetic resin material or a metallic plate and a diffuser capable of spreading light and diffracting, spreading and transmitting light into two directions or diffracting, spreading and reflecting light in one direction.

Abstract: A method of producing an antireflection structure for use on a display or a window surface or both in an electronic device, such as a mobile phone. The display can be an LCD with a top polarizer and a bottom polarizer. The antireflection structure is imparted on the top polarizer by a roller embossing process. In particular, the embossing is carried out in the same manufacturing process when the polarizer is produced. The antireflection structure has a plurality of sub-wavelength periodic grooves. The antireflection structure on the window surface can be imparted using an embossing process or an injection molding process.

Abstract: An aberration compensating optical element includes: a diffractive structure having a plurality of ring-shaped zone steps formed into substantially concentric circles on at least one surface of the aberration compensating optical element; wherein the aberration compensating optical element is adapted for being disposed on an optical path between a light source for emitting a light having a wavelength of not more than 550 nm, and an objective lens made of a material having an Abbe constant of not more than 95.

Abstract: An optical system includes a diffractive optical element having a diffraction grating provided, on a lens surface having a curvature, in a concentric-circles shape rotationally-symmetrical with respect to an optical axis. The sign of the curvature of the lens surface having the diffraction grating provided thereon is the same as the sign of a focal length, at a design wavelength, of a system composed of, in the optical system, a surface disposed nearest to an object side to a surface disposed immediately before the lens surface having the diffraction grating provided thereon, and is different from the sign of the distance from the optical axis to a position where the center ray of an off-axial light flux enters the lens surface having the diffraction grating provided thereon. Further, the apex of an imaginary cone formed by extending a non-effective surface of the diffraction grating is located adjacent to the center of curvature of the lens surface having the diffraction grating provided thereon.

Abstract: An optical element has diffractive grooves. Each diffractive groove includes a first surface approximated by a predetermined optical function; a second surface extending in a direction to cross the first surface and being parallel to the optical axis; and a third surface to connect the first surface and the second surface. A width of the third surface in the direction perpendicular to the optical axis is 0.5% to 15% of the sum of a width of the first surface in the direction perpendicular to the optical axis and the width of the third surface in the direction perpendicular to the optical axis.

Abstract: A Littrow grating (1) comprises a multiplicity of parallel diffraction structures (3) succeeding one another periodically. The latter are arranged on a support (2) defining a base area (4). A diffraction structure (3) comprises a blaze flank (5) inclined towards the base area (4) substantially at the Littrow angle (&dgr;). In addition the diffraction structure (3) comprises a counter-flank (6) which forms with the blaze flank (5) at the apex of a diffraction structure (3) an apex angle (&agr;) which is less than 90°. The counter-flank (6) comprises at least two substantially plane area sections (7, 8). The latter extend, bordering one another and inclined relative to one another through an angle of inclination (&bgr;), parallel with the extension direction of the diffraction structure (3). Due to the inclination of the at least two area sections (7, 8) relative to one another, the counter-flank (6) exhibits all in all a concave surface viewed from the light incidence side.

Abstract: A diffractive optical element including a stack of first, second and third optical regions or a stack of first, second, third and fourth optical regions, a first relief pattern formed between the first and second optical regions, and a second relief pattern formed between the second and third or between the third and fourth optical regions. The first and second relief patterns have substantially identical pitch distributions and are substantially aligned in a direction of an optical axis. Depths of the first and second relief patterns are set such that a wavelength dependency of diffraction efficiency can be decreased over a wavelength range to be used. It is possible to manufacture in a simple manner at a low cost a diffractive optical element in which undesired flares and ghosts are suppressed.

Abstract: An optical component including: a substrate made from heat absorptive glass having a front surface and a rear surface, at least one of said surfaces being a crenulate surface having optical power.

Abstract: The present invention provides a different optical element having superior optical characteristics. A polycrystalline substrate having crystal grains whose sizes are not more than 1 &mgr;m or an amorphous phase at the dry-etched surface thereof, or an upper film layer 8 formed on a polycrystalline substrate 1 being the same materials as that of the polycrystalline substrate 1, which has finer crystal grains than-those of the substrate. The upper film layer 8 is dry etched, and AR coat 6 is formed thereon.

Abstract: The objective lens is a biconvex plastic lens having first and second surfaces which are both aspheric. The objective lens is divided into an inside area which is inside of a circle of an effective diameter of the objective lens and an outside area which is outside of the circle of the effective diameter. A diffractive lens structure having a plurality of concentric ring-shaped steps is formed in the inside area. A surface of the outside area is continuous with no steps and corresponds to a macroscopic base curve of the inside area. The objective lens has a gap of a spherical aberration between the inside area and the outside area.

Abstract: In a diffraction element, a diffraction grating is formed with a grating pitch having different diffraction angles in accordance with a wavelength of a laser light beam incident thereon. The wavelength is variable in accordance with an environment temperature. The diffraction element is made of a material having a linear expansion coefficient which causes thermal variation in the grating pitch enough to compensate at least a part of the diffraction angle variation due to environment temperature change.

Abstract: An optical element has diffractive grooves. Each diffractive groove includes a first surface approximated by a predetermined optical function; a second surface extending in a direction to cross the first surface and being parallel to the optical axis; and a third surface to connect the first surface and the second surface. A width of the third surface in the direction perpendicular to the optical axis is 0.5% to 15% of the sum of a width of the first surface in the direction perpendicular to the optical axis and the width of the third surface in the direction perpendicular to the optical axis.

Abstract: The invention relates to an element for the combined symmetrization and homogenization of a beam of rays and to a method for designing an element of this type.

Abstract: A filter synthesis technique for realizing an arbitrary (amplitude- and phase-specified) transfer function for narrow-band incident optical signals, using a quasi-periodic echelle structure. In an ordinary (periodic) diffraction grating, the fixed spacing of its rulings is chosen in order that the device exhibit a very narrow spectral peak at a particular center wavelength, for a given angle of incidence, when the output is observed at the appropriate diffraction angle. In accordance with the present invention, the basic periodic structure is spatially perturbed in both the center spacing and width of its rulings in such a manner as to spread the spectral peak into an arbitrary spectral shape in the vicinity of what was (in the original, unperturbed grating) a narrow peak. In addition, the phase transfer function over the spectral range of interest may be tailored to fit any desired spectral phase profile.

Abstract: In a volume phase grating, a plurality of phase gratings for causing a refractive index of a substrate having an incident surface and a launched surface facing each other to be cyclically changed between the incident surface and the launched surface are so formed as to be inclined at a specified angle to the incident surface. The volume phase grating is constructed such that an incident light is caused to be obliquely incident on the incident surface, and an angle of inclination of the phase gratings to the incident surface is set such that the incident light obliquely incident on the incident surface is refracted at the incident surface and perpendicularly incident on the phase gratings.

Abstract: A transmitted type diffractive optical element comprises a transparent plate made of a material having a refractive index n2, whereas the transparent plate is in contact with a medium having a refractive index n1. A number of projections are arranged with a period L on the first surface side of the transparent plate. Each projection has a rectangular cross section with a height H and a width W. An antireflection layer is formed on the second surface of the transparent plate. When the light L1 having a wavelength &lgr; is incident on the first surface at an incident angle &thgr;, the transmitted type diffractive optical element satisfies (2n1L/&lgr;)sin &thgr;=1, and n2/n1≦3 sin &thgr;, whereas each of the diffraction efficiencies of transmitted first-order diffracted light L31 in TE and TM polarization modes is at least 0.8.

Abstract: An optical arrangement has a light source which emits coherent light of a specific wavelength. Further provided is an optical Littrow grating, arranged at a specific Littrow angle &thgr;L. It has a multiplicity of parallel diffraction structures following one another periodically at an interval in each case of one specific grating period and arranged on a substrate predetermining a base area. The light wavelength, the grating period and the Littrow angle &thgr;L are tuned to one another in such a way that the grating is used in one of the largest diffraction orders m for light reflected back at the Littrow angle &thgr;L, which still fulfils the condition: (2(m+1)/m−1) sin (&thgr;L)≧1 An optical arrangement of this kind has an increased reflection efficiency.

Abstract: New grating structures include a bonded transmission grating structure. The grating structure is encapsulated by two pieces that are bonded together. In addition, a new method of making grating structures includes forming wells with an aspect ratio (depth:width) of at least 3:1, 7:1 or greater. Such grating structures can be used to form gratings with high diffraction efficiencies for both TE and TM polarizations of light.

Abstract: This invention relates to a platform (11) and a method for generating electromagnetic field distributions. The invention relates in particular to optical sensors for measuring biological or chemical substances. The platform (11) according to the invention comprises a substrate (13), a structured layer (19) and, positioned between the substrate (13) and the structured layer (19), a multilayer assembly (17), said components being so matched relative to one another that upon appropriate impingement by electromagnetic radiation an electromagnetic field distribution is generated that is at a maximum within the structured layer (19).

Abstract: In a diffractive optical element, which is formed by laminating at least three layers of diffraction gratings made of at least three kinds of materials which differ in dispersion, at least three design wavelengths are set.