Abstract: Methods and compositions are provided for detecting biomolecular interactions. The use of labels is not required and the methods can be performed in a high-throughput manner. The invention also provides optical devices useful as narrow band filters.

Abstract: A tunable interferometer for creating gratings of variable periodicity in an optical waveguide is disclosed. The interferometer includes a beam splitter for producing first and second write beams from an input beam. First and second reflectors receive the first and second write beams, respectively, from the beam splitter and direct the first and second write beams to intersect at a fixed location. The angle of intersection of the first and second write beams is a function of impingement locations of the first and second write beams on the first and second reflectors. The impingement locations of the first and second write beams on the first and second. reflectors may be varied to vary the angle of intersection at the fixed location.

Abstract: A fiber Bragg grating may be written at an arbitrary wavelength without extensive recalibration or reconfiguration of the writing equipment in some embodiments. A pair of writing beams may be used to expose the fiber. The crossing angles of the writing beams may be adjusted.

Abstract: Imaging system for a microscope based on extreme ultraviolet (EUV) radiation. The present invention is directed to a reflective imaging system for an x-ray microscope for examining and object in an object plane, wherein the object is illuminated by rays of a wavelength of less than 100 nm, particularly less than 30 nm, and is imaged in a magnified manner in an image plane. In the imaging system, according to the invention, for a microscope based on extreme ultraviolet (EUV) radiation with wavelengths in the range of less than 100 nm, with a magnification of 0.1× to 1000× and a structural length of less than 5 m, at least one of the imaging optical elements 2 and 3 in the beam path has a diffractive-reflective structure which is arranged on a spherical or plane area and has a non-rotationally symmetric, asymmetric shape. The arrangement according to the invention provides an imaging system which avoids the disadvantages of the prior art and ensures a high imaging quality.

Abstract: Disclosed is a diffractive optical element which is made of at least two materials of different dispersions and which includes at least two diffraction gratings being accumulated one upon another, wherein each diffraction grating is formed on a curved surface of a substrate, and wherein a diffraction grating, of the at least two diffraction gratings, in which a curvature radius of the curved surface and a curvature radius of a grating surface in a portion where a grating pitch is largest, have different signs, is one of the at least two diffraction gratings which has a smallest grating thickness.

Abstract: A diffraction optical element wherein a plurality of diffraction gratings formed of at least two kinds of materials differing in dispersion are laminated, at least two of the plurality of diffraction gratings are formed on a curved surface and adjacent to each other, and these two adjacent diffraction gratings are equal to each other in the shape of a curved tip plane in which the tips of respective grating portions are ranged.

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 method of fabricating an optical waveguide grating having a plurality of grating lines of refractive index variation comprises the steps of: (i) repeatedly exposing a spatially periodic writing pattern onto a photosensitive optical waveguide: and (ii) moving the writing light pattern and/or the waveguide between successive exposures of the writing light pattern, so that each of at least a majority of the grating lines is generated by at least two exposures to different respective regions of the writing light pattern.

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: Disclosed is a zoom lens system which uses a diffractive optical element such that high optical performance can be obtained over the overall power variation range. The zoom lens system includes a first lens unit having positive optical power, and a second lens unit having negative optical power and disposed on a rearward side of the first lens unit. A diffractive optical portion is provided on a cemented surface, which is convex toward a forward side, in the first lens unit or the second lens unit.

Abstract: A zoom lens includes a first lens unit having a positive optical power, a second lens unit having a negative optical power, a third lens unit having a positive optical power, and a fourth lens unit having a negative optical power in sequence from an object side. The zoom lens executes zooming by moving all the four lens units on an optical axis. At least one of the four lens units has at least one diffractive optical surface. By this arrangement, the size of the zoom lens can be easily reduced while securing a desired variable power ratio and correcting lateral chromatic aberration that is varied by zooming.

Abstract: The present invention provides a scanning device with the following features: the system is capable of writing data to record carriers of a first format because it is corrected for chromatic aberration resulting from fast wavelength variations during write operation; it has a diffractive element with a generally sawtooth-like pattern, such that it may for example be manufactured in a single-step replication process; the system has high efficiency for scanning first optical record carriers (e.g. DVDs) and acceptable efficiency for scanning second optical record carriers (e.g. CDs); and the lens provides limited spherochromatism and the system is thus able to cope with wavelength variations.

Abstract: A single element objective lens for an optical disc drive converges a laser beam, which is emitted by a laser source, on a data recording surface of an optical disc through a protective layer of the optical disc. One surface of the objective lens is divided into a central area including an optical axis thereof and a peripheral area surrounding the central area. The peripheral area is provided with a diffraction lens structure formed by a plurality of concentric annular zones including minute steps. The central area is a continuous surface having no stepped portions. The diffraction lens structure compensates for variation of converging characteristic of the objective lens due to a change of a temperature.

Abstract: A diffractive optical element has a plurality of diffraction structures for a certain wavelength. These each have a width measured in the plane of the diffractive optical element and a height measured perpendicularly thereto. The widths and the heights of the diffraction structures vary over the area of the diffractive optical element. An optical arrangement comprising such a diffractive optical element has, in addition, a neutral filter. The efficiency of such a diffractive optical element and of such an arrangement can be optimized locally for usable light.

Abstract: A lens optical system is provided with a cemented lens element formed by cementing two constituent lens elements made of different optical materials together, with a diffractive optical surface formed at the cementing interface between the two constituent lens elements. The two constituent lens elements have at their respective interfaces with air a radius of curvature different from the radius of curvature that they have at the cementing interface.

Abstract: An objective lens for recording information on and/or reproducing information from and optical information recording medium, comprises a diffractive structure including ring-shaped diffractive zones on at least one surface thereof. The objective lens is a single lens made of plastic material, at least on surface thereof is an aspheric surface, and the following conditional formula is satisfied; NA≧0.7 where NA represents an image side numerical aperture necessary for recording on and/or reproducing from an optical information recording medium.

Abstract: An imaging element includes a diffraction optical element on which an off-axis beam with a field angle is incident and a stop. Of beams having different field angles and incident on the diffraction optical element, beams having incident angles larger than the incident angle of a principal light ray of the beams incident on the grating surface of the diffraction optical element are partially shielded by a light-shielding member, so that the diffraction efficiencies of orders adjacent to a design order are kept low and hence imaging performance almost free from flare can be achieved even if a beam with a field angle is incident.

Abstract: A lens system includes a lens, a grating and a non-periodic phase structure. The lens system is a-thermalised by a compensation of the temperature-dependence of the spherical aberration of the lens by the temperature-dependence of the spherical aberration of the non-periodic phase structure and the grating. The lens system is also a-spherochromatised by a compensation of the wavelength-dependence of the spherical aberration of the grating by the wavelength-dependence of the spherical aberration of the non-periodic phase structure.

Abstract: A method for designing a diffractive lens that separates an incident light beam into a plurality of beams and condenses the respective separated beams is provided. The method includes: defining an expression of a diffractive surface having a beam converging function based on given focal length; defining an expression of a diffractive surface having a beam separating function that separates a light beam into plural orders of diffractive light based on said given focal length, a given number of separated light and a given distance between focusing points; and superimposing the defined expressions of the diffractive surface having the beam converging function and the diffractive surface having the beam separating function to determine a shape of the diffractive lens having a plurality of optical functions.

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 Littman configuration type wavelength tuning mechanism comprising an LD block (1), a grating (3) and a wavelength adjusting mirror (4).

Abstract: An objective lens for an optical pick-up has a refractive lens element provided with a diffraction lens structure on at least one surface thereof. The diffraction lens structure has a plurality of annular zones. The objective lens is capable of converging at least two beams having different wavelengths on at least two types of optical discs having different data recording densities, respectively. The objective lens is partitioned into a common area through which a beam with a low NA passes, and an exclusive high NA area which is designed to converge a beam with a high NA. The boundaries of the annular zones formed on the exclusive high NA area are designed independently from boundaries obtained from an optical path difference function so that the beam with the high NA is converged substantially on a certain point and the beam with the low NA is diffused.

Abstract: A diffraction optical element is configured such that a plurality of annular zones having minute steps extending in a direction of the optical axis therebetween are formed on a base element. The plurality of annular zones include narrow and wide zones respectively satisfying conditions (1) and (2): &Dgr;Z(i)<(1/2)·&Dgr;E(i)  (1), and &Dgr;Z(i)>(3/2)·&Dgr;E(i)  (2), wherein, i represents the order of the steps counted from the optical axis, &Dgr;E(i) represents an absolute value of an OPD provided by the i-th step, and &Dgr;Z(i) represents an absolute value of a difference between OPDs provided, with respect to a base curve, by an inner side end portion and outer side end portion of an annular zone between an i-th step and (i+1)-th step.

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: 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: In a lens system having one or a plurality of diffracting surfaces and one or a plurality of refracting surfaces, a power of each surface and a distance between the surfaces are set such that an optical characteristic of the lens system, such as a focal length (focal point) and/or a spherical aberration, remains substantially unvarying relative to temperature variations within a predetermined range and that an achromatic effect is substantially attained for the focal length (focal point) and/or the spherical aberration within a predetermined region of wavelength.

Abstract: An external pupil lens system (200) with an entrance pupil distance at least three times that of the effective focal length. The lens system is comprised of several conventional lenses and a diffractive optical element (DOE) for secondary chromatic aberration correction. In the illustrative embodiment, the system includes an entrance pupil (50), followed by a lens group (52) containing two refractive elements for primary color correction. Next along the optical axis is lens group (54), which contains two refractive elements for astigmatism and higher order coma correction, followed by lens group (60), which contains one refractive element (62) and one DOE (64) for secondary color correction.

Abstract: A lens optical system is provided with a cemented lens element formed by cementing two constituent lens elements made of different optical materials together, with a diffractive optical surface formed at the cementing interface between the two constituent lens elements. The two constituent lens elements have at their respective interfaces with air a radius of curvature different from the radius of curvature that they have at the cementing interface.

Abstract: A phase mask (15) for modulating a collimated light beam passing therethrough, the light beam being diffracted to photoinduce a refractive index profile in a photosensitive optical medium, the phase mask (15) comprises a substrate (17) having an outer surface provided with a plurality of parallel grating corrugations (19). The grating corrugations (19) have a non-uniform relief depth across the outer surface for photoinducing a non-uniform refractive index profile in the photosensitive optical medium. The non-uniform relief depth is defined by a variable thin film layer (21) of variable thickness overlaying the substrate (17). The grating corrugations (19) can either be etched into the variable thin film layer (21) itself or be etched into the substrate (17), with the variable this film layer (21) being deposited on it after etching. Methods to make such phase masks are also provided.

Abstract: An ultraviolet-permeable resin is used for a substrate of a diffraction grating, and at least one grating portion formed from ultraviolet cured resin is provided onto a surface of the substrate, thereby alleviating performance deterioration that is caused by heat expansion and the like due to environmental changes and enabling a large angle of view and cost reduction due to the simple construction. Further, a diffractive optical element using the diffraction grating, and an optical system using the diffractive optical element, are also obtained.

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: In one embodiment of the invention, a transmitting spectral filter includes a thin film layer and a grating structure. The thin film layer is made of transmitting material to transmit a first incident radiation within a first band around a first wavelength. The first incident radiation is reflected from a mirror in an optical path. The grating structure is deposited on the thin film layer and is etched to have a grating period. The grating period causes transmission of the first incident radiation within the first band and causes at least one of reflection and diffraction of the second incident radiation above a second wavelength out of the optical path.

Abstract: Disclosed is a scanning optical system, which is provided with a light source portion, a deflector, which deflects a beam emitted from said light source portion, and a scanning lens for converging the beam deflected by the deflector onto a surface to be scanned. The scanning lens has a positive power as a whole, and includes a plurality of refractive lens elements. Further, a diffractive lens structure is formed on at least one surface of one of the plurality of lens elements of the scanning lens. The diffractive lens structure is defined by an optical path difference function that is asymmetrical with respect to the optical axis of the refractive lens in the main scanning direction, which is counterbalanced with an asymmetrical movement of a deflecting point, compensating a lateral chromatic aberration.

Abstract: The present disclosure describes a technique for creating diffraction gratings on curved surfaces with electron beam lithography. The curved surface can act as an optical element to produce flat and aberration-free images in imaging spectrometers. In addition, the fabrication technique can modify the power structure of the grating orders so that there is more energy in the first order than for a typical grating. The inventors noticed that by using electron-beam lithography techniques, a variety of convex gratings that are well-suited to the requirements of imaging spectrometers can be manufactured.

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 condenser system for generating a beam of radiation includes a source of radiation light that generates a continuous spectrum of radiation light; a condenser comprising one or more first optical elements for collecting radiation from the source of radiation light and for generating a beam of radiation; and a diffractive spectral filter for separating first radiation light having a particular wavelength from the continuous spectrum of radiation light. Cooling devices can be employed to remove heat generated. The condenser system can be used with a ringfield camera in projection lithography.

Abstract: Optical systems employing stepped diffractive surfaces (13) are provided. Ray tracing through such systems is performed using the grating equation to represent the stepped diffractive surface (SDS). In this way, the SDS can be used to correct a variety of monochromatic and chromatic aberrations by balancing the aberrations of the SDS against the aberrations of non-stepped optical surfaces in the system.

Abstract: An optical filter has little variation in chromatic dispersion over its passband, the filter being constituted by a Bragg grating whose pitch varies as a function of distance along the filter with a change in the sense of its concavity. The filter also presents apodization, e.g. apodization by a super-Gaussian function or Blackman apodization. The filter of the invention is adapted to high data rate dense WDM transmission systems.

Abstract: A light transmitting device comprising or incorporating a broadband Bragg grating that is formed in the direction of light propagation with grating regions of alternatingly high and low refractive index. The grating regions are formed with periodicity P and are structured as to amplitude, periodicity and/or phase in a manner which varies periodically with a modulation period L>P. Also, either one or the other or both of the grating period P and the modulation period L is or are chirped over substantially the full extent of the grating. The grating exhibits a spectral response in which broad rcflection peaks appear at each side of a reflection peak centred on the Bragg wavelength and fall under an envelope determined by the Fourier transform of the periodic modulation function.

Abstract: The optical system of this invention is an unique type of imaging spectrometer, i.e. an instrument that can determine the spectra of all points in a two-dimensional scene. The general type of imaging spectrometer under which this invention falls has been termed a computed-tomography imaging spectrometer (CTIS). CTIS's have the ability to perform spectral imaging of scenes containing rapidly moving objects or evolving features, hereafter referred to as transient scenes. This invention, a reflective CTIS with an unique two-dimensional reflective grating, can operate in any wavelength band from the ultraviolet through long-wave infrared. Although this spectrometer is especially useful for rapidly occurring events it is also useful for investigation of some slow moving phenomena as in the life sciences.

Abstract: A method for fabricating an error-free linear position encoder incorporates the generation of fringes on a holographic plate by the interference of light from two point sources. The fringes are projected onto a curved holographic plate without intervening optical elements, the curve being such that the fringes have a constant pitch along the surface of the plate. A methodology for generating such a curve includes the creation of a graphic representation of the hyperbolic fringes generated by the interference between two coherent point sources, which would fall on an appropriately curved holographic plate. A numerical technique derived from the graphic representation produces a “constant-pitch” curve such that all of the fringes projected onto the curve are equidistant. The holographic plate, coated with a photosensitive material, is fabricated or formed in the shape of the constant-pitch curve.

Abstract: Disclosed is a diffractive optical element which includes a diffractive grating pattern on a base plate. The diffractive grating pattern includes a plurality of phase gratings arranged in parallel lines extending along a predetermined direction to cause diffraction of an incident beam. Each of the plurality of phase gratings has an asymmetrical phase pattern. There is a phase gap, &Dgr;P, representing a phase difference (in radians) between an end point and a beginning point of each phase pattern. The phase gap, &Dgr;P, is substantially equal for each of the plurality of phase gratings and satisfies the relationship. 0.7&pgr;<|&Dgr;P|<1.2&pgr;.

Abstract: Method of fabricating an optical waveguide grating having a plurality of grating lines of refractive index variation including (i) repeatedly exposing a spatially periodic writing light pattern onto a photosensitive optical waveguide; and (ii) moving at least one of the writing light pattern and the waveguide between successive exposures of the writing light pattern, so that each of at least a majority of the grating lines is generated by at least two exposures to different respective regions of the writing pattern.

Abstract: In a lens system having one or a plurality of diffracting surfaces and one or a plurality of refracting surfaces, a power of each surface and a distance between the surfaces are set such that an optical characteristic of the lens system, such as a focal length (focal point) and/or a spherical aberration, remains substantially unvarying relative to temperature variations within a predetermined range and that an achromatic effect is substantially attained for the focal length (focal point) and/or the spherical aberration within a predetermined region of wavelength.

Abstract: A method of fabricating an optical waveguide grating having a plurality of grating lines of refractive index variation comprises the steps of: (i) repeatedly exposing a spatially periodic writing, light pattern onto a photosensitive optical waveguide, and (ii) moving the writing light pattern and/or the waveguide between successive exposures of the writing light pattern, so that each of at least a majority of the grating lines is generated by at least two exposures to different respective regions of the writing light pattern.

Abstract: Disclosed is a diffractive optical element which is made of at least two materials of different dispersions and which includes at least two diffraction gratings being accumulated one upon another, wherein each diffraction grating is formed on a curved surface of a substrate, and wherein a diffraction grating, of the at least two diffraction gratings, in which a curvature radius of the curved surface and a curvature radius of a grating surface in a portion where a grating pitch is largest, have different signs, is one of the at least two diffraction gratings which has a smallest grating thickness.

Abstract: An optical element includes an incidence surface, one or more reflecting surfaces reflecting light from the incident surface, an emergence surface, and off-axial curved surfaces causing the light to emerge from the emergence surface. At least one of the incidence surface, the emergence surface and the one or more reflecting surfaces is a surface having diffracting action. The surface having the diffracting action is a curved surface.

Abstract: An optical device is described. In one embodiment, the optical device includes first and second concave diffraction gratings, first and second concentrators, first and second sets of fibers, and an array of optical elements. The first concave diffraction grating reflects light from an input beam into multiple light waves of different wavelengths focused at spatially separate locations. The first concentrator has a first set of light guiding channels to transfer the light waves. The first set of fibers is optically coupled to the first set of light guiding channels. The array of optical elements includes optical elements that have at least one input and at least one output. Such inputs of each optical element in the array is coupled to one of the first set of light guiding channels. The second set of fibers is optically coupled to outputs of optical elements in the array. The second concentrator has a second set of light guiding channels.

Abstract: A luminous flux diameter variable type objective lens having a wavelength selectivity is disposed within a luminous flux. Arranged on a surface of the lens are a first region 11 with no diffraction gratings, and a second region 12 with diffraction gratings. The diffraction gratings each having a rectangular cross section are linearly arranged in the second region 12. The thickness (height) h of the diffraction grating 12A is set to such a value that the ratio of ± first-order diffracted light becomes much greater for the light having a wavelength of 780 nm used for CD-R, whereas the ratio of zero-order diffracted light becomes substantially 100% for the light having a wavelength of 635 nm used for DVD.

Abstract: A compound objective lens is composed of a hologram lens or transmitting a part of incident light without any diffraction to form a beam of transmitted light and diffracting a remaining part of the incident light to form a beam of first-order diffracted light, and an objective lens for converging the transmitted light to form a first converging spot on a front surface of a thin type of first information medium and converging the diffracted light to form a second converging spot on a front surface of a thick type of second information medium. Because the hologram selectively functions as a concave lens for the diffracted light, a curvature of the transmitted light differs from that of the diffracted light.