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: 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: 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.

Abstract: Disclosed is a grid polarizer comprising a substrate; and a plurality of stacked metal and dielectric layers, having a width w, disposed on the substrate and forming a parallel grid of stacked layers. The stacked layers are spaced apart to form a repetition space between the stacked layers, such that no diffraction orders are allowed to propagate except the zero order. The grid polarizer that is capable of transmitting substantially all illumination of a given polarization while suppressing at least of portion of the illumination reflected due to an orthogonal polarization component.

Abstract: In order to obtain a diffractive optical element with which a high diffraction efficiency can be obtained in a wide wavelength range and color flare is not noticeable and a picture taking apparatus using this diffractive optical element, an image is formed on a picture taking unit by using a diffractive optical element in an optical system. The diffractive optical element has a grating structure obtained by stacking a plurality of diffraction gratings made of at least two types of materials with different dispersion properties to enhance diffraction efficiency for a particular design order throughout a predetermined wavelength region and a plurality of design wavelengths which exist in a predetermined design order and at which a maximum optical path length difference in the grating structure becomes an integer multiple of a wavelength, the diffractive optical element having a design wavelength &lgr;0 satisfying predetermined conditions.

Abstract: A diffraction grating includes a metallic base layer and layers of dielectric materials of varying refractive index, where a bottom interface of the layers is adherent to the metallic base layer. The dielectric layers are periodically spaced on top of the metallic base layer, leaving the metallic base layer exposed in regions. This grating allows for the polarization insensitive reflective properties of the base metallic layer to operate in conjunction with the polarization sensitive diffraction properties of the multilayer grating structure to provide near 100% diffraction efficiency over a reasonable wavelength bandwidth, independent of the polarization of the incident beam.

Abstract: A first diffractive optical element pattern with a pattern pitch that is no greater than a wavelength of incident light is formed on a first main surface of substrate such as a glass plate. Second diffractive optical element patterns are formed at positions that are respectively incident to positive first-order diffracted light and negative first-order diffracted light produced by the first diffractive optical element pattern. Negative first-order diffracted light produced by each second diffractive optical element pattern is incident upon a boundary face of the substrate at an angle that is smaller than the critical angle, and so exits the substrate.

Abstract: An optical element of which diffraction efficiency hardly varies with wavelength is provided by using an optical material satisfying the conditions that nd>−6.667×10−3vd+1.70 and &thgr;g,F≦−2×10−3vd+0.59 where nd is a refractive index at d-line, vd is an Abbe number at the d-line, and &thgr;g,F is a second order dispersion at d-line, whereby diffraction efficiency is improved in any working visible wavelength region and more precise chromatic aberration correction is obtained.

Abstract: The invention provides a method for producing a diffractive optical element, including forming first and second gratings, substantially in mutual registration, of at least first and second optical materials, such that for predetermined two or more wavelengths, the diffractive optical element has desired phase retardations, thereby avoiding the generation of chromatic aberrations. The invention further provides a diffractive optical element.

Abstract: Diffractive pigment flakes include single layer or multiple layer flakes that have a diffractive structure formed on a surface thereof. The multiple layer flakes can have a symmetrical stacked coating structure on opposing sides of a reflective core layer, or can be formed with encapsulating coatings around the reflective core layer. The diffractive pigment flakes can be interspersed into liquid media such as paints or inks to produce diffractive compositions for subsequent application to a variety of objects. The diffractive pigment flakes can be formed with a variety of diffractive structures thereon to produce selected optical effects.

Abstract: An optical device (10) including a first semiconductor layer (12) on which is deposited a dielectric layer that is patterned and etched to form dielectric strips (14) as part of a diffraction grating layer. Another semiconductor layer (16) is grown on the first semiconductor layer (12) between the dielectric strips (14), resulting in alternating dielectric sections (14) and semiconductor sections. In an alternate embodiment, a dielectric layer is deposited on a first semiconductor layer (64), and is patterned and etched to define dielectric strips (66). The semiconductor layer (64) is etched to form openings (68) between the dielectric strips (66). Another semiconductor material (70) is grown within the openings (68) and then another semiconductor layer (72) is grown over the entire surface after removing the dielectric strips (66). Either embodiment may be modified to provide diffraction grating with air channels (20).

Abstract: A laminate-type diffractive optical element which is easily producible and which allows high optical performance to be easily achieved, and an optical system using the same, are disclosed. In the diffractive optical element formed by laminating a plurality of diffraction gratings, when the distance between the uppermost portion of one diffraction grating and the lowermost portion of the other diffraction grating in two diffraction gratings adjacent to each other along the incident direction of a light is represented by D (&mgr;m), these two diffraction gratings are arranged to satisfy the following relation: 10 &mgr;m<D<40 &mgr;m.

Abstract: A diffractive optical element for white light is composed of a plurality of layers of optical materials and has a relief pattern constituting a diffraction grating formed at least at one cementing interface between the two different optical materials. The grating height of the relief pattern constituting the diffraction grating is defined by the following formula: h=&lgr;/|n−n′| where h represents the grating height of the relief pattern constituting the diffraction grating; &lgr; represents the wavelength (here it is assumed that &lgr;≦450 (nm)); n represents the refractive index of the optical material abutting the interface from the object side for light of the wavelength &lgr;; and n′ represents the refractive index of the optical material abutting the interface from the image side for light of the wavelength &lgr;.

Abstract: A method of preparing a composite micro relief element. The micro relief element comprises a first layer of a first substrate and a second layer of a relief forming polymer comprising an overlay and at least one relief feature portion. The method includes the steps of forming a line of contact between the receptive surface and at least one mold feature formed in a flexible dispensing layer, applying a quantity of resin to fill the mold feature along the line of contact. Moving the line of contact across the receptive surface whereby sufficient resin is captured by the mold feature and a quantity of resin passes the line of contact to form the overlay portion. The resin is then cured and the flexible dispensing layer is released.

Abstract: An optical element according to the invention uses a thin film-like two-dimensional photonic crystal having a structure of periodic repetition in two directions perpendicular to each other. When the two periodic directions are Y-axis and Z-axis directions, opposite surfaces of the photonic crystal structure perpendicular to the Z-axis direction and parallel to the Y-axis direction are used as a light input surface and a light output surface respectively. The direction of movement of light rays incident onto the light input surface is decided so that it is parallel to the YZ plane and inclined at a predetermined inclination angle to the Z-axis direction.

Abstract: A diffractive optical element includes a diffraction optical part provided with a phase-type diffraction grating. The diffraction grating of the diffraction optical part has on the surface thereof minute uneven structure of which the period is substantially constant. The period is smaller than a wavelength used.

Abstract: A SiO2 thin film is formed on a SiO2 substrate provided with a binary-type diffractive element by a radiofrequency sputtering process so as to cover the fine irregularities formed on the substrate caused by misalignment of masks in the production process. This film planarizes the surface having the fine irregularities and thus prevents a decrease in diffraction efficiency.

Abstract: A diffractive optical element includes a plurality of laminated diffraction grating surfaces. Each of the diffraction grating surfaces is formed to have a sufficiently small grating thickness as compared with a grating pitch thereof.

Abstract: A diffractive optical element includes at least a first diffractive element and a second diffractive element. The conditional expression 0.5≦D/DS≦0.9 is preferably satisfied where DS denotes the summation of the optimum designed groove height of the first diffractive element d1S and that of the second diffractive element d2S, and D denotes the summation of an actual groove height of the first diffractive element d1 and that of the second diffractive element d2. At least one of the first diffractive element and the second diffractive element is made of glass. At least one of the first diffractive element and the second diffractive element is made of resin. The optimum designed value of groove heights of the diffractive optical element are determined so as to satisfy a condition for correcting chromatic aberration at both d-line and g-line.

Abstract: An optical instrument is described in which a diffractive element is located at a focal or image plane of the instrument and the diffractive element is effective to produce an array of a plurality of exit pupils at a viewing position for the instrument and thereby to form an enlarged exit pupil for the instrument. The diffractive element is formed to provide a plurality greater than two of optical diffractive gratings each being disposed angularly relative to others of the plurality of optical diffractive gratings.

Abstract: A surface capable of supporting surface charge oscillations and exhibiting a profiled grating, said profile comprising at least two superposed periodic profiles. The surface has applications as radar absorber and authentication devices. Also disclosed is a method of detecting the authenticity of an object comprising providing a surface as described above claim adjacent to or on the object, illuminating said surface with radiation from at least one angle and determining the reflectivity characteristics and comparing this with reflectivity characteristics of a reference surface.

Abstract: A diffractive optical element acts as a lens. The optical element has a diffraction grating. The diffractive grating is provided with a plurality of ridges. Each of the ridges has a transmissive surface. A sectional profile of the transmissive surface is composed of a plurality of successively connected strait lines of an identical length. The length varies from one ridge to another.

Abstract: A diffractive optical element is composed of a plurality of diffraction gratings which differ in dispersion from each other and are laminated while being spaced to enhance diffraction efficiency for a particular order (design order) throughout an entire usable wavelength region, wherein edges of at least part of corresponding grating portions of the plurality of diffraction gratings are shifted from each other in a direction of arrangement of grating portions of each diffraction grating.

Abstract: An improved optical system is provided for diffusing light uniformly over a wide angle, including, a diffractive element for diffracting light received by the system in multiple diffraction orders, and a diffusing element which diffuses the diffracted light. The diffractive element provides diffracted light having an angular distribution of intensities over the diffraction orders which is correlated to the power spectrum of the diffusing element such that the system produces a predetermined intensity distribution of diffused light. The diffraction period of the diffractive element is selected such that the angular separation between the zeroeth and first diffraction orders is approximately one-half the angular extent of the full-width-at-half-maximum of the power spectrum of the diffusing element. The strengths of the diffraction orders are selected such that the combination of diffused light from each diffractive order provides uniformity in the intensity of the diffused light from the system.

Abstract: In a diffractive optical element, first and second diffraction gratings of 10 &mgr;m or less in thickness made from materials of respective different Abbe numbers are laminated through an air layer. The grating thickness of the first diffraction grating is made to be 7.5 &mgr;m, and the grating thickness of the second diffraction grating is made to be 6.54 &mgr;m. Glass of the Abbe number of 63.8 is used for the material of the first diffraction grating, and an ultraviolet curable polymer of the Abbe number of 23.0 is used for the material of the second diffraction grating. Accordingly, the diffraction efficiency of the diffractive optical element is improved to 97% or higher throughout the entire visible spectrum.

Abstract: A zoom lens includes three lens units which are a first unit having a negative refracting power, a second unit having a positive refracting power, and a third unit having a positive refracting power arranged in the stated order from the side of an original surface. Zooming is effected by changing an air space between the first unit and the second unit and an air space between the second unit and the third unit. The second unit has a diffractive optical element.

Abstract: An optical system includes a diffractive optical element having a diffraction grating provided, on a lens surface having curvature, in a concentric-circles shape rotationally-symmetrical with respect to an optical axis. A sign of the curvature of the lens surface having the diffraction grating provided thereon is the same as a sign of a focal length, in 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 a sign of a distance from the optical axis to a position where a center ray of an off-axial light flux enters the lens surface having the diffraction grating provided thereon. Further, an 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 overcoat protected diffraction grating. A replica grating having a thin aluminum reflective grating surface is produced by replication of a master grating or a submaster grating. The thin aluminum reflective surface may be cracked or have relatively thick grain boundaries containing oxides and hydroxides of aluminum and typically is also naturally coated with an aluminum oxide film. The grating is subsequently recoated in a vacuum chamber with a thin, pure, dense aluminum overcoat and then also in the vacuum the aluminum overcoat is coated with a thin film of MgF2. The grating is especially suited for use for wavelength selection in an ArF laser operating producing an ultraviolet laser beam at a wavelength of about 193 nm. The oxygen free aluminum overcoat prevents the ultraviolet light from causing damage by stimulating chemical reactions in grating materials under the aluminum grating surface or in the aluminum oxide film. The MgF2 additionally prevents oxidation on the surface, of the aluminum overcoat.

Abstract: An optical device for making light converge produces a convergent light beam with a satisfactorily great numerical aperture and acceptably small aberrations. The optical device has a plurality of diffraction gratings that each make light converge. The light shone into the optical device is passed through one after another of those diffraction gratings in such a way that the light is made to converge to a higher degree every time it passes through one of the diffraction gratings. The diffraction gratings may be all transmissive, all reflective, or a combination of both. The diffraction gratings are formed on a surface of or at an interface inside the optical device, and two diffraction gratings may be formed on a single surface. The light is made to eventually converge on the exit surface of the optical device so that the optical device functions as a solid immersion device.

Abstract: The present invention provides a diffraction optical element comprising a first optical member having a first diffraction grating, a second optical member having a second diffraction grating, wherein the first and second optical members are stacked so that the first and second diffraction gratings face each other inside the stacked members and so that a space is formed between the diffraction gratings, and a sealing member for hermetically sealing the space between the diffraction gratings.

Abstract: A diffraction optical element comprises a substrate, a diffraction grating formed on the substrate with a material with low ultraviolet resistance and an ultraviolet screening means arranged on the substrate at a position closer to the incident light receiving side of the optical element relative to the diffraction grating. The ultraviolet screening means comprises a dielectric multilayer film and is formed on the other side of the substrate than the side carrying the diffraction grating. Alternatively, the ultraviolet screening means may be provided as a separate member from a diffraction optical element and arranged at a position closer to the incident light receiving side of the diffraction optical element in an optical system.

Abstract: To obtain a diffractive optical element of high diffraction efficiency over a wide range of wavelengths with no conspicuous color flare and a photographic optical system having the diffractive optical element, at least two diffraction gratings of different materials in dispersion are stratified, the first order is chosen as the design order and two wavelengths which, when multiplied one times, amounts to the maximum optical path length difference in the grating structure are used as the design wavelengths, wherein each of the values of the plurality of design wavelengths is determined so as to make white or nearly white flare caused by the diffracted light in the zero and second orders.

Abstract: Disclosed is an illumination system using optical feedback to maintain a predetermined illumination output. The illumination system employs an electrically controllable optical filter for filtering light incident thereon. The illumination system also includes a light detector for detecting at least a portion of the light filtered by the electrically controllable optical filter. The light detector is in data communication with the electrically controllable optical filter. Some or all light filtered by the electrically controllable optical filter is detected by the light detector, which, in turn generates a corresponding signal that is compared to at least one predetermined value. If the signal generated by the light detector differs when compared to the at least one predetermined value, one or more filtering characteristics of electrically controllable optical filter are varied which, in turn, varies the amount of light filtered by the electrically controllable optical filter.

Abstract: In a diffractive optical element having a diffraction grating formed at an interface between different substances, a total sum of values obtained by multiplying rates of change in refractive index due to temperature variations of the substances by a grating thickness of the diffraction grating is smaller than a useful wavelength.

Abstract: A diffracting optical element has a structure that a plurality of layers having a periodic relief pattern varying in height in a period are laminated in proximity to or close contact with each other. The diffracting optical element includes two layers equal in the height of the relief pattern and opposite to each other in the direction in which the height of the relief pattern varies in a period, and another layer differing in the height of the relief pattern from the two layers. Materials forming the three layers differ in dispersion from one another.

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: A diffractive optical element has a plurality of step-like patterns each having surface levels of a number less than eight, the step-like patterns being disposed in combination to provide a function of a step-like structure of eight or more levels.

Abstract: A metrology for determining bias or overlay error in lithographic processes. This metrology includes a set of diffraction test patterns, optical inspection techniques by using spectroscopic ellipsometer or reflectometer, a method of test pattern profile extraction. The invention uses a set of diffraction gratings as the test patterns, and thin film metrology equipment, such as spectroscopic ellipsometer or spectroscopic reflectometer. The profiles of the test patterns in the two successive layers are analyzed. Overlay information are obtained after processing the profile data. In a first aspect of the invention, a line-on-line overlay grating test patterns structure is disclosed in which a second layer mask is placed in the center of a clear line in a first layer mask. In a second aspect of the invention, a line-in-line overlay grating test patterns structure is disclosed in which a second layer mask is placed in the center of a dark line in the first mask.

Abstract: Transparent and semitransparent diffractive elements, particularly holograms with a diffractive pattern created at least in one of two following layers with different index of refraction: a transparent bearing layer (1) from polymer or copolymer having index of refraction n<1.7, and a holographic effect-enhancing, high refraction index layer (2) formed by chalcogenide based substances comprising at least one element from the group sulphur selenium, tellurium, said layer (2) has n>1.7 and its melting temperature is lower than 900° C. The diffractive element can further contain a protective layer (6) and/or an adhesive layer (7) and/or a fragile layer (8) and/or an anchoring layer (9).

Abstract: An improved diffraction grating for wavelength division multiplexing/demultiplexing devices is disclosed. The improved diffraction grating has a glass substrate, a polymer grating layer located adjacent to the glass substrate, and a metal coating layer located adjacent to the polymer grating layer. The improvement comprises a polymer coating layer located adjacent to the metal coating layer, and a glass cover located adjacent to the polymer coating layer, wherein the polymer coating layer and the glass cover compensate for thermal characteristics associated with the polymer grating layer and the glass substrate, respectively.

Abstract: The present invention provides a diffractive optical element having superior optical characteristics.

Abstract: A holographic element, which can be manufactured without the use of an anisotropic material and comprises a corrugated surface configuration whose grooves and ridges have moderate depth and height corresponding to the pitch of the corrugated surface configuration, is provided together with a method of manufacturing same. The holographic element is for switching light paths in dependence on the polarization directions of an incident light and comprises a plurality of regions formed substantially periodically on a substrate, by which regions the transmitted light has different phase differences between its polarization components as a whole. Within one cycle of the substantially periodically formed regions, at least one of the regions is such a region in which a corrugated configuration of one-dimensional structure with a pitch not greater than the wavelength of the incident light is formed.

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.

Abstract: There is provided an optical low pass filter passing only a lower spatial frequency using a phase grating and the structure of the grating. The optical low pass filter utilizes the two-dimensionally arranged phase grating for the purpose of removing an image with a higher spatial frequency in an imaging system employing a semiconductor solid-state imaging device such as CCD image sensor or CMOS image sensor, The optical low pass filter which suppresses a spatial frequency component higher than a specific frequency and passes a component lower than the specific frequency in an imaging system sensing input images includes a grating generating the phase shift of 0, a grating generating the phase shift of &phgr;, arranged at the right and bottom of the 0-phase shift grating, and a grating generating the phase shift of 2&phgr;, arranged at the diagonal side of the 0-phase shift grating.

Abstract: A diffraction grating for use in multiplexing and demultiplexing optical signals in optical communication systems having reduced polarization sensitivity has a plurality of grooves including reflective step surfaces and transverse riser surfaces separated by a flat. The step surfaces have a reflective coating and the riser surfaces do not have a reflective coating. A method of making a reflective diffraction grating includes forming a plurality of grooves in a substrate, the grooves having a step surface for reflecting an incident beam, a transverse riser and a flat therebetween and providing a reflective coating on the steps and not on the risers.

Abstract: Techniques for fabricating a well-controlled, quantized-level, engineered surface that serves as substrates for EUV reflection multilayer overcomes problems associated with the fabrication of reflective EUV diffraction elements. The technique when employed to fabricate an EUV diffraction element that includes the steps of: (a) forming an etch stack comprising alternating layers of first and second materials on a substrate surface where the two material can provide relative etch selectivity; (b) creating a relief profile in the etch stack wherein the relief profile has a defined contour; and (c) depositing a multilayer reflection film over the relief profile wherein the film has an outer contour that substantially matches that of the relief profile. For a typical EUV multilayer, if the features on the substrate are larger than 50 nm, the multilayer will be conformal to the substrate. Thus, the phase imparted to the reflected wavefront will closely match that geometrically set by the surface height profile.

Abstract: A diffractive optical element for white light is composed of a plurality of layers of optical materials and has a relief pattern constituting a diffraction grating formed at least at one cementing interface between the two different optical materials. The grating height of the relief pattern constituting the diffraction grating is defined by h=&lgr;/n−n′|, where h represents the grating height of the relief pattern constituting the diffraction grating; &lgr; represents the design wavelength, which is less than or equal to 450 nm; n represents the refractive index of the optical material abutting the interface from the object side for light of the wavelength &lgr;; and n′ represents the refractive index of the optical material abutting the interface from the image side for light of the wavelength &lgr;.

Abstract: In a laser processing method for accurately forming a convexo-concave structure on the surface of a glass substrate, a periodic optical intensity distribution of a laser beam is obtained by an interference between diffracted light beams of +1 degree and −1 degree emitted from a phase mask, onto which the laser beam is irradiated, in the vicinity of the emission side of the phase mask, and a glass substrate, on which a thin film is formed, is set in the area where the periodic optical intensity distribution is provided. As a result, the thin film is evaporated or ablated depending on the periodic optical intensity, thereby a diffraction grating, which has the same period as that of the varying optical intensity, is formed on the glass substrate.

Abstract: A surface pattern comprises microscopically fine relief structures that diffract visible light. When the surface pattern is illuminated perpendicularly with white light, the surface pattern appears with bright and dark regions from a first viewing direction. The length and/or position and/or number of bright and dark regions changes as the viewing angle changes. Preferably, the contour of the surface pattern is selected so that the length or position of the bright regions changes markedly when the viewing angle changes.

Abstract: Disclosed is a diffractive optical element which includes a substrate made of a fluoride compound, and a diffraction grating formed on the substrate by use of an oxide compound such as a fluoride compound or a metal oxide, for example.