Abstract: A mirror which reflects input light from a lens which focuses light emitted from a VIPA, and returns the light to the lens is constituted as a multi-faced mirror including multiple reflection surfaces in the traveling direction of the input light which individually reflect light with a different wavelength, and have a different shape. As a result, an apparatus which has a small optical loss, and generates a different wavelength dispersion depending on a channel signal wavelength of a WDM signal.

Abstract: Pre-sensitization techniques can be used in conjunction with holographic recording materials to allow high quality holographic stereograms to be recorded in those holographic recording materials using pulsed lasers. Additional hologram production system hardware and software designs for use with pulsed lasers are disclosed.

Abstract: A security element is embedded in a layer composite of plastic material and has reflecting, optically variable surface patterns which can be visually recognized from predetermined observation directions and which are formed from a mosaic of surface elements occupied by optically active structures. A part of the surface pattern is additionally covered by a regularly arranged matrix of unit cells. Each unit cell is occupied by a single elementary surface or a group of identical surface portions that contain optically active structures which are independent of the mosaic of the surface pattern. The arrangement of the elementary surfaces and the surface portions in the matrix form an item of concealed information which is not perceptible to the naked eye, in the form of graphic or alphanumeric characters which however are reproduced in a color photocopy with a color or gray value contrast which is perceptible to the naked eye.

Abstract: A method of recording holograms includes: generating a first signal-beam from a signal-beam source and a first reference beam from a reference-beam source; recording a first hologram in a holographic medium from an interference between the first signal beam and the first reference beam; shifting the reference-beam source after the act of recording the first hologram; generating a second signal beam from the signal-beam source and a second reference beam from the reference-beam source after the act of shifting the reference-beam source following the recording of the first hologram; and recording a second hologram in the holographic medium from an interference between the second signal beam and the second reference beam.

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 apparatus for filtering electromagnetic waves and sensing deposition of chemical species, the apparatus having a substrate having a surface relief structure containing at least one dielectric body with physical dimensions smaller than the wavelength of the filtered electromagnetic waves, such structures repeated in a two dimensional array covering at least a portion of the surface of the first substrate. The apparatus may include one, two, or more such arrays, spaced from one another to create one or more cavities between the arrays.

Abstract: A tuneable optical filter includes a moveable filter plate and an associated optical region for filtering an input radiation beam to provide corresponding filtered output radiation. The optical region has spatially varying filtration properties. Piezoelectric actuating elements are provided for moving the filter plate and its associated optical region relative to the beam for selecting a portion of the optical region for use in filtering the beam and thereby tuning the filter. The actuating elements are operable when driven by electrical signals to repetitively engage or be in repetitively slidable contact and thereby impart a lateral force to a surface of the filter plate for moving the optical region relative to the beam in at least one dimension. The filter is especially suitable for use in optical communication systems where there arises a need for occasional system reconfiguration involving retuning optical filters of the system.

Abstract: The present invention relates to a method and a system for the storage of data in the form of volume holograms which do not mutually overlap. The storage medium consists of a high-sensitive material in the form of a plate of thickness D, in which a single hologram is essentially shaped as a cylinder with the minimal possible cross-section. The signal light beam is modulated with data and directed onto the plate-shaped storage material by means of a lens or a conventional optical system, illuminating an area of the material which, for a given amount of data, is the smallest possible. To record a hologram, a reference light beam is used, incident upon the storage material either from the same direction as the signal beam, or opposite thereto. The hologram is only written in the portion where the signal and the reference beams overlap.

Abstract: The present invention relates to a process for gratings able to resist dizziness, enhance color displayed, eliminate static electricity and block radiation. Steps included are: making a substrate with an enhanced glass or optical plastic glass or optical plastics; coating the surface of the substrate with dizziness-resistant films composed of evenly distributed nano-particles, wherein the inner layer is made of Cu particles or Al particles and the outer layer is made of Cr particles; forming a static-electricity-resistant layer on the grating's surface so as to form an optical diffraction grating able to resist dizziness, enhance color displayed, eliminate static electricity and block radiation.

Abstract: A dot matrix system, which uses an electronic display panel as a diffractive optical device to produce two laser beams. The interference pattern of these two beams, at the focal plane of a lens, forms a grating spot with a shape and beam profile determined by the wavefronts diffracted by the electronic display device. The invention uniquely combines aspects of the interfering beam prior art and the prior art using an imaging display. Instead of simply reducing a diffraction image on a display device as in the imaging display prior art, the invention puts two different Fourier transforms on the display, the laser beam interacts with these Fourier transforms, and a lens focuses the two beams on the recording medium, with the two beams interfering with each other to produce the desired grating pattern. Because multiple orders of the wavefront will be produced by the display device, a light blocking element is used, with an aperture to pass only the desired order(s) of the beams.

Abstract: A method and apparatus for stretching a pulse, shaping a stretched pulse, and modeling a stretched and/or shaped pulse are disclosed. An etalon has a port, a partially reflective surface, and a fully reflective surface. A base pulse is introduced into the etalon, and a plurality of portions of the base pulse propagating from the etalon are collected. The collected portions are then combined to generate a stretched pulse whose width is proportional to the width of the base pulse. This can be modeled by assigning a transmission factor value to each one of a plurality of taps and a reflection factor value to each one of the taps, excepting only one tap. A transport delay for is assigned to each tap to which a reflection factor value was assigned, wherein the transport delay is proportional to the width of a base pulse.

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 apparatus for analyzing material, such as coal, comprises subjecting the coal (14) to laser light The laser light is used to vaporize and ionize a small amount of the coal to produce spectral emissions. A plurality of detection, (26, 30, 34) each of which detect a part of the spectrum of the spectrum emissions, collect spectral information and pass it to data collection means (38, 40, 42). The data is then analyzed to determine the presence and/or amount of one or more elements or species in the coal. In a preferred embodiment, the apparatus, has a plurality of data collection means (26, 30, 34), with each of the plurality of detection means being associated with a respective data collection means (38, 40, 42). The apparatus provides rapid and accurate analysis of the coal. The apparatus may be used to analyze coal on conveyor belt or coal in a seam in the ground.

Abstract: An optical device has a light-transmitting optical substrate formed with a multilayer film and a barrier layer disposed on the multilayer film side thereof. The light-transmitting optical substrate has a refractive index Ns (at a reference wavelength of 632.8 nm) falling within the range of 1.7≦Ns≦1.9, whereas the barrier layer has a refractive index Nb (at a reference wavelength of 632.8 nm) falling within the range of −0.1≦Nb−Ns≦0.1.

Abstract: A bandpass filter containing specific combinations of the dyes to yield filters which are adapted to selectively transmit predetermined primary color wavelengths of an electromagnetic spectrum as well as selectively absorb wavelengths other than the predetermined primary color wavelengths. The multiple bandpass filters are employed to improve the images on CRT screens and plasma display panels.

Abstract: An optical deflection element for splitting light rays in accordance with a wavelength of incident light, includes a photonic crystal having an entrance end face and an exit end face, and having a refractive index which periodically changes depending upon positions thereof. The optical deflection element includes a region in which a propagation angle &thgr;C of the incident light within the photonic crystal changes in accordance with the wavelength of the incident light having entered at an incident angle &thgr;IN into the entrance end face, and a relationship among a wavelength &lgr; of the incident light in vacuum, a lattice constant A of the photonic crystal, the incident angle &thgr;IN and the propagation angle &thgr;C satisfies (∂&thgr;C/∂(A/&lgr;))/(∂&thgr;C/∂&thgr;IN)>10.

Abstract: A display system includes a diffraction grating that generates exit-pupil images, where one of the exit-pupil images has a first intensity and the remaining exit-pupil images each have or approximately have a second intensity that is less than the first intensity. The system also includes a filter that attenuates the intensity of the one exit-pupil image. In one example, the filter attenuates the 0th-order exit-pupil image so that all of the exit-pupil images have the same or approximately the same intensities.

Abstract: A lithographic illuminator to illuminate a reticle to be imaged with a range of angles is provided. The illumination can be employed to generate a pattern in the pupil of the imaging system, where spatial coordinates in the pupil plane correspond to illumination angles in the reticle plane. In particular, a coherent synchrotron beamline is used along with a potentially decoherentizing holographic optical element (HOE), as an experimental EUV illuminator simulation station. The pupil fill is completely defined by a single HOE, thus the system can be easily modified to model a variety of illuminator fill patterns. The HOE can be designed to generate any desired angular spectrum and such a device can serve as the basis for an illuminator simulator.

Abstract: A diffraction grating providing reduced polarization dependent loss. The elements of pixels of the diffraction grating are fixed or actuated such that some grating elements are actuated to correspond to a positive polarization dependent loss and others are actuated to correspond to a negative polarization dependent loss. The pixels may include multiples of three grating elements or multiples of four grating elements. An electrostatic beam structure providing increased actuation in a direction away from a substrate may be used in a diffraction grating providing reduced polarization dependent loss.

Abstract: An interleaver is provided with an optical system configured to split light having traveled from a first port to a half mirror, into two beams and direct the beams toward first and second reflectors, respectively. Light reflected by the first reflector and arrived at the half mirror is split into two beams and directed toward second and third ports, respectively. Light reflected by the second reflector and arrived at the half mirror is split into two beams directed toward the second and third ports, respectively. An etalon filter configured to cause a loss on either one of light incident thereto from the first port and the beams directed toward the second port and toward the third port.