Abstract: An optical device such as an overlay panel for a LCD display, comprises an element of light-transmitting material having a surface configured to form a stepped Fresnel prismatic structure. The light-transmitting material itself or ribbed light refracting element, said element incorporates an array of graded refractive index features adapted to impart light dispersing of diffusing characteristics to the light-transmitting material. In an alternative arrangement, the element of light-transmitting material has a layer configured to form a stepped Fresnel-type surface and an additional layer incorporating such an array of graded refractive index features.

Abstract: A variable dispersion compensator comprising: an optical incidence/output device for propagating wavelength division multiplexed light; an optical multiple reflector on which the wavelength division multiplexed light emitted from the optical incidence/output device is incident for repetitive reflections; and an optical reflection device for reflecting the wavelength division multiplexed light emitted from the optical multiple reflector toward the optical multiple reflectors, the device composed of a second lens and a reflecting element and being capable of controlling the distance from the optical multiple reflector. A temperature adjusting element and a temperature detecting element are arranged via a thermal-conductive elastic member on a surface of the optical multiple reflector at a portion where no drop occurs in the intensity of the wavelength division multiplexed light incident/emitted. The temperature of the optical multiple reflector is controlled by a controller.

Abstract: This invention relates to light transmitting filters comprising: (a) a light absorbing layer of material having a front surface and a back surface, (b) transparent microspheres embedded in the light absorbing layer and contacting the front surface of the light absorbing layer with portions of the microspheres protruding through the back surface of the light absorbing layer for transmitting light through the light absorbing layer, and (c) a conformed layer of optically clear material having a front surface and a back surface wherein the front surface of the conformed layer is in contact with and conforming in shape with the protruding portions of the microspheres, and wherein the back surface of the conformed layer has a textured finish. The invention also relates to methods of making these light transmitting filters.

Abstract: A method capable of quantitatively evaluating the intensity of scintillation caused by surface unevenness. Light from a white light source is made incident on a surface of an object to be measured through a matrix filter. Reflected light or transmitted light from the object is photographed with a CCD camera and taken into a computer as data. Image processing for the luminance distribution of the captured light is performed to obtain a standard deviation of dispersion of the luminance distribution. The value of the standard deviation obtained is defined as a scintillation value of the surface of the object. The performance of the object is evaluated by judging whether or not the scintillation value is greater than a predetermined value.

Abstract: A method and system for providing an isolator/polarization beam deflector is disclosed. The method and system include a first collimator, a core and a second collimator. The first collimator collimates a plurality of optical signals traveling in a first direction. The core receives the optical signals from the first collimator. The core includes first and second birefringent wedges and a rotator between the first and second birefringent wedges. The first collimator, the first birefringent wedge and the rotator transmit the optical signals such that the optical signals cross at an interface between the rotator and the second birefringent wedge. The core transmits the optical signals with a deflection, combines the optical signals to provide a combined optical signal and prevents a reflected portion of the optical signals from traveling opposite to the first direction. The second collimator receives and couples the combined optical signal to the output.

Abstract: High speed optical scanner systems and methods using optical multiplexing of wavelengths and spatial codes. In one form, a wavelength multiplexed optical scanner (W-MOS) is disclosed, wherein tuning the wavelength or selection of wavelength accomplishes a high speed, no-moving, parts scanner coupled with a wavelength dispersive element, such as a grating or a thin-film interference filter. In another form, a W-MOS employs beam expansion optics and a freespace-coupled wavelength dispersive element. In another embodiment, the invention includes a fiber-based W-MOS using an optical fiber coupled with a fiber-based wavelength division multiplexer (WDM) device to form a spatially distributed scanner for wide angular coverage in three-dimensional beam scanning. The invention also includes a code multiplexed optical scanner (C-MOS) that uses the principle of holography and spatial code multiple access optical communications.

Abstract: A laser beam irradiation device, comprising a light source for emitting a laser beam, a cylindrical lens, an optical system for entering the laser beam to the cylindrical lens perpendicularly with respect to a center line of the cylindrical lens, and a luminous flux rotating means for rotating the incident laser beam around an optical axis of the laser beam.

Abstract: A window baffle assembly has a multi-element segmented window having a first surface adapted to receive at least one wavelength of radiation from an optical system, a baffle housing positioned proximate at least a portion of the first surface of the segmented window, and a plurality of baffle elements each affixed between positions on the baffle housing and offset from the first surface of the window. At least a portion of the plurality of baffle elements are in a Field of View of the optical system at an operational angle. The surface of the baffle elements are adapted to absorb at least a portion of the energy of the radiation and oriented to scatter the radiation. Each baffle element comprises a leading edge and an opposing trailing edge, the leading edge oriented toward the first surface of the window and the trailing edge oriented to point toward a central point of the optical system. A method of manufacturing a window baffle assembly is also provided.

Abstract: Rays of light having respective wavelengths angular-dispersed and output from a VIPA plate are collected by a lens, and diffracted by a grating pair which is an optical path shift generation unit and optical path shift amount variation unit, and have a shift in a path of rays having different wavelengths. When the rays are reflected by a dispersion leveling three-dimensional mirror and input into the VIPA plate again, they are received by portions having different dispersion compensation amount of the three-dimensional mirror, thereby realizing different amounts of wavelength dispersion for respective wavelengths, and independently adjusting an amount of wavelength dispersion of the entire wavelengths of the WDM rays and the wavelength dispersion slope.

Abstract: A deinterleaver includes three polarization interferometers and a dispersion compensator, the input light beam containing all channels passing through the dispersion compensator and the first polarization interferometer, the light beam being separated by a polarization beam splitter into an even channel beam and an odd channel beam with the even channel beam passing through a second polarization interferometer and the odd channel beam passing through a third polarization interferometer. A dispersion compensated deinterleaver as above in which all three polarization interferometers have pass bands corresponding to all channels and in which there are two output ports. A dispersion compensated deinterleaver in which the first polarization interferometer has pass bands for all channels, the second polarization interferometer has pass bands for even channels, the third polarization interferometer has pass bands for odd channels and in which there are four output ports.

Abstract: A method and apparatus for control of optical trap arrays and formation of particle arrays using light that is in the visible portion of the spectrum. The method and apparatus provides a laser and a time variable diffractive optical element to allow dynamic control of optical trap arrays and consequent control of particle arrays and also the ability to manipulate singular objects using a plurality of optical traps. By avoiding wavelengths associated with strong absorption in the underlying material, creating optical traps with a continuous-wave laser, optimizing the efficiency of individual traps, and trapping extended samples at multiple points, the rate of deleterious nonlinear optical processes can be minimized.

Abstract: A spectral dispersion device includes a transmission member formed of a translucent material and formed with an image surface, a reflection surface, and a dispersion surface. The image surface includes an image that receives a ray of visible light therethrough and into the interior of the transmission member, with the ray of light being reflected off the reflection surface within the interior of the transmission member and being dispersed through the dispersion surface to display a light pattern in the form of a spectrally-dispersed representation of the image. The light pattern is visible from the exterior of the transmission member by an observer and varies according to the position of the observer with respect to the dispersion surface.

Abstract: A spectrometer uses collimated, P-polarized light made incident on a surface of an optically transparent material at angle &thgr;INC. The material transmits the light which reaches a boundary surface between the input material and an output optically transparent material. The input material is preferably highly dispersive, making Snell component values at the boundary surface markedly different for different wavelengths. The output material is preferably of low dispersion and high birefringence. Only one wavelength at the boundary surface has a Snell component value tangent to its corresponding index surface in the output section. Within this section, the ray vector for this wavelength is parallel to the boundary surface. Because optical energy propagates in the ray vector direction, only the narrow range of wavelengths having ray vectors substantially parallel to the boundary surface reach an output surface of the device. This narrow range of wavelengths comprises the passband incident on a detector.

Abstract: A field-of-view controlling arrangement such as a privacy screen includes a single microprism or lenticular sheet having a plurality of sets of parallel surfaces that intersect to form prisms or lenticular structures, and in which field-of-view control is achieved by (i) for sheets made up of parallel “one-dimensional” microprism or lenticular structures having at least two intersecting sets of mutually parallel surfaces, altering at least two sets of the mutually parallel surfaces, and/or portions of the at least two sets of mutually parallel surfaces, by applying a light-attenuating treatment, (ii) for sheets made up of polyhedral lenticular structures having at least three intersecting sets of mutually parallel surfaces, or at least one set of curved surfaces extending in directions transverse to directions in which the field-of-view is to be limited, altering at least one set of the mutually parallel or curved surfaces by applying a light-attenuating treatment, or (iii) for any type of micropr

Abstract: There is provided a light diffusion sheet comprising a light diffusion layer formed on a transparent substrate and containing a binder resin and resin particles that impart an uneven surface, wherein the uneven surface of the light diffusion layer exhibits an arithmetical mean deviation of 2.0 &mgr;m or more in three-dimensional surface roughness measurement and/or ten point height of irregularities of 10.0 &mgr;m or more in three-dimensional surface roughness measurement. This light diffusion sheet is high luminance in the front direction, is excellent in light-diffusing property, and is resistant to damage.

Abstract: A VIPA plate having a configuration where a translucent reflection film and a total reflection film are respectively arranged on one side and the other side of a transparent parallel plate can be used as a wavelength dispersion compensator by using a special mirror and a lens. However, the transparency characteristic of the wavelength dispersion compensator using such a VIPA plate is a periodical characteristic which is asymmetric with a central wavelength in a wavelength regime. Accordingly, not parallel light but converged or diverged light having angular dispersion is input to an etalon plate, so that a filter whose transparency characteristic is an asymmetric periodical characteristic which is reverse to the VIPA plate is configured for the central wavelength in the wavelength regime. With this filter, the transparency characteristic of the wavelength dispersion compensator using the VIPA plate is optimized.

Abstract: A method capable of quantitatively evaluating the intensity of scintillation caused by surface unevenness. Light from a white light source is made incident on a surface of an object to be measured through a matrix filter. Reflected light or transmitted light from the object is photographed with a CCD camera and taken into a computer as data. Image processing for the luminance distribution of the captured light is performed to obtain a standard deviation of dispersion of the luminance distribution. The value of the standard deviation obtained is defined as a scintillation value of the surface of the object. The performance of the object is evaluated by judging whether or not the scintillation value is greater than a predetermined value.

Abstract: A method and device for providing tunable dispersion compensation by splitting an incoming optical beam and then recombining interferometrically two sub-beams which have been passed through fixed dispersive (dispersion producing) elements. The polarization of the incoming optical signal is controlled and the signal beam is split into sub-beams at a ratio dependent on the polarization. The sub-beams are directed to each of two interferometer arms. The return beams are interfered e.g. by placing a quarter waveplate at 45° to the two orthogonal polarization axes. This produces a near-lossless beam with a tunable amount of dispersion dependent on the ratio of beam split.

Abstract: An optical apparatus for producing chromatic dispersion. The apparatus includes a virtually imaged phased array (VIPA) generator, a mirror and a lens. The VIPA generator receives an input light at a respective wavelength and produces a corresponding collimated output light traveling from the VIPA generator in a direction determined by the wavelength of the input light, the output light thereby being spatially distinguishable from an output light produced for an input light at a different wavelength. The mirror has a cone shape, or a modified cone shape. The lens focuses the output light traveling from the VIPA generator onto the mirror so that the mirror reflects the output light. The reflected light is directed by the lens back to the VIPA generator. In this manner, the apparatus provides chromatic dispersion to the input light.

Abstract: The present invention provides a dispersion compensator which utilizes a Virtually Imaged Phased Array (VIPA), gratings, and birefringent wedges to moderate chromatic dispersion, dispersion slope and polarization mode dispersion. The dispersion compensator in accordance with the present invention propagates the composite optical signal in a forward direction; separates the wavelengths in the band of wavelengths in each of the plurality of channels, where each of the wavelengths in the band is spatially distinguishable from the other wavelengths in the band; spatially separates each band of wavelengths in the plurality of channels; spatially separates each wavelength of each separated band of wavelengths into a plurality of polarized rays; and reflects the plurality of polarized rays toward a return direction, where dispersion is added to the reflected plurality of polarized rays such that the unwanted chromatic dispersion, dispersion slope, and PMD are compensated.

Abstract: A reflective display device that is capable of improving a light efficiency in a reflective liquid crystal display in which a light is obliquely inputted from a peripheral light source or an auxiliary light source. In the device, an optical medium is provided with an inclined surface for refracting an incident light and refracting a light reflected from a reflective display part such that an obliquely inputted external light is vertically incident, to the reflective display part. Accordingly, it becomes possible to maximize a light efficiency of the reflective liquid crystal display at which a light is obliquely inputted from the peripheral light source or the auxiliary light source.

Abstract: Antireflection coating on a substrate which is coated with a low refractive index layer having a specified refractive index which in turn is coated with a high refractive index layer having a higher refractive index than the low refractive index layer, is either characterized in that a roughened surface which scatters and reflects the incident light entered into the low refractive index layer in contact with the substrate is formed at the interface between the low refractive index layer and the substrate, or that a light-diffusing layer which scatters and reflects the incident light entered into the low refractive index layer in contact with the substrate is formed at the interface between the low refractive index layer and the substrate, or that a hard coating layer in contact with the low refractive index layer is formed by dispersing a light-diffusing material in the hard coating layer, which scatters and reflects the incident light entered into the low refractive index layer.

Abstract: A variable dispersion compensator comprising an optical incidence/output device for propagating wavelength division multiplexed light; an optical multiple reflector on which the wavelength division multiplexed light emitted from the optical incidence/output device is incident for repetitive reflections; and an optical reflection device for reflecting the wavelength division multiplexed light emitted from the optical multiple reflector toward the optical multiple reflectors the device composed of a second lens and a reflecting element and being capable of controlling the distance from the optical multiple reflector. A temperature adjusting element and a temperature detecting element are arranged via a thermal-conductive elastic member on a surface of the optical multiple reflector at a portion where no drop occurs in the intensity of the wavelength division multiplexed light incident/emitted. The temperature of the optical multiple reflector is controlled by a controller.

Abstract: A waveguide optical monitor is disclosed. The device has an optical input port coupled through a switch to a plurality of input waveguides. A dispersive element disperses light within the input optical waveguides toward a plurality of output waveguides. There are a plurality of photodetectors each optically coupled to an output waveguide. The photodectors are for sensing an intensity of light within the waveguide with which it is optically coupled. An optical switch in optical communication with the optical input port and for switching light received at the optical input port to one of the plurality of input waveguides.

Abstract: A tunable spectral source includes an enclosure having first and second apertures; an optical dispersive element positioned in the enclosure; and multiple pixel source elements that are individually controllable for selectively directing one or more broadband light signals through the first aperture to irradiate the optical dispersive element. Each of the broadband light signals irradiates the optical dispersive element at a unique angle of incidence. The optical dispersive element disperses the broadband light signals into spectral component signals at dispersion angles that are dependent upon the angle of incidence of each broadband light signal that irradiates the optical dispersive element. The portions of the spectral component signals that are emitted through the second aperture are determined by selecting one or more particular pixel source elements to irradiate the optical dispersive element.

Abstract: The invention features an apparatus and method for separating an optical beam including multiple wavelength components into targeted subsets of wavelengths by causing different subsets of wavelength components either to undergo a total internal reflection (TIR) at or to transmit through internal surfaces of refractive media.

Abstract: A tunable filter includes a polarizer, a polarization rotator, a diffraction grating and a diffraction grating adjustor. The polarizer polarizes a light beam and splits the light beam into first and second light beams. The polarization rotator rotates a plane of polarization of the first light beam at 90° to generate a rotated light beam. The diffraction grating receives the rotated light beam and the second light beam. The diffraction grating adjustor adjusts the diffraction grating to change incident angles of the rotated light beam and second light beam.

Abstract: A reconfigurable bi-directional wavelength selective switch and variable optical attenuator is disclosed. It has an optical system that is symmetric about a polarization modulator. The symmetric optical system consists of an input birefringent optical system and output birefringent optical system disposed around polarization modulator. The optical system delivers the wavelength channels that are to be switched as a superimposed wavelength channel incident the polarization modulator. As a result, crosstalk is reduced below −35 dB and greater optical performance is achieved.

Abstract: The present invention provides a dispersion compensator which utilizes a Virtually Imaged Phased Array (VIPA), gratings, and birefringent wedges to moderate chromatic dispersion, dispersion slope and polarization mode dispersion, and a method and system for testing such a dispersion compensator.

Abstract: This invention relates to light transmitting filters comprising: (a) a light absorbing layer of material having a front surface and a back surface, (b) transparent microspheres embedded in the light absorbing layer and contacting the front surface of the light absorbing layer with portions of the microspheres protruding through the back surface of the light absorbing layer for transmitting light through the light absorbing layer, and (c) a conformed layer of optically clear material having a front surface and a back surface wherein the front surface of the conformed layer is in contact with and conforming in shape with the protruding portions of the microspheres, and wherein the back surface of the conformed layer has a textured finish. The invention also relates to methods of making these light transmitting filters.

Abstract: A method and apparatus for control of optical trap arrays and formation of particle arrays using light that is in the visible portion of the spectrum. The method and apparatus provides a laser and a time variable diffractive optical element to allow dynamic control of optical trap arrays and consequent control of particle arrays and also the ability to manipulate singular objects using a plurality of optical traps. By avoiding wavelengths associated with strong absorption in the underlying material, creating optical traps with a continuous-wave laser, optimizing the efficiency of individual traps, and trapping extended samples at multiple points, the rate of deleterious nonlinear optical processes can be minimized.

Abstract: An illumination system for a color projection display. In one embodiment a broad spectrum light source illuminates a multilevel optical phase element which disperses the broad spectrum light from the light source by diffraction. A display having a number of pixel elements, each capable of transmitting a predetermined spectral region, is positioned within the near field region of the multilevel optical phase element so as to receive the light dispersed by the multilevel phase element.

Abstract: A spectral dispersion device includes a transmission member formed of a translucent material and formed with an image surface, a reflection surface, and a dispersion surface. The image surface includes an image that receives a ray of visible light therethrough and into the interior of the transmission member, with the ray of light being reflected off the reflection surface within the interior of the transmission member and being dispersed through the dispersion surface to display a light pattern in the form of a spectrally-dispersed representation of the image. The light pattern is visible from the exterior of the transmission member by an observer and varies according to the position of the observer with respect to the dispersion surface.

Abstract: The present invention provides an improved tunable chromatic dispersion compensator. The compensator includes: a virtually imaged phased array (VIPA); at least one reflector optically coupled to the VIPA; a mirror optically coupled to the at least one reflector; and a movable reflector holder coupled to the at least one reflector, where the movable reflector holder moves the at least one reflector such that a length of a beam path between the VIPA and the at least one reflector and the mirror is variable. The present invention uses the VIPA to produce a controlled variable degree of chromatic dispersion within a plurality of optical channels so as to compensate for unwanted chromatic dispersion in an optical communications system. Positional adjustment of the movable reflector holder permits variable control of the beam path length between the VIPA and the focusing lens.

Abstract: A multiplexing/demultiplexing optical circuit provides a demultiplexed output spectrum of channels having a flat amplitude response without sacrificing optical power. A phased array implementation and a diffraction grating implementation both rely on a first dispersion of the beam to be demultiplexed and subsequent division of the wavelengths into channels. Local inversion is induced within each channel of the dispersed wavelengths about a channel central wavelength. After the wavelengths are spatially inverted, they are once again provided to a dispersion element or array effectively nullifying the dispersion effects across the channel band to provide output channels having a substantially “flat-tops”, while providing good channel separation through global dispersion of all the wavelengths.

Abstract: A device for the adjustable coupling of wavelengths or wavelength regions into the illumination beam path of a microscope, preferably in the beam path of a confocal microscope, comprising at least one dispersive element for wavelength separation of the illumination light and at least one at least partially reflecting element arranged in the wavelength-separated portion of the illumination light for reflecting back a wavelength region in the direction of the microscope illumination, and a device for the adjustable detection of object light coming from an illuminated object, preferably in a microscope beam path, comprising at least one dispersive element for wavelength separation of the object light and means arranged in the wavelength-separated portion of the object light for the adjustable stopping down or cutting out of at least one wavelength region and deflection in the direction of at least one detector.

Abstract: A reflective-type diffraction grating structure for use in color display devices such as liquid crystal displays (LCDs). It contains: (1) a plurality of micro-lenses each having a smooth top surface and a blazed zig-zag-shaped grating surface at the bottom; (2) an optical coating formed below the zig-zag-shaped grating surface; and (3) a reflective member formed below the optical coating. With the cooperative actions of the zig-zag-shaped grating surface, the optical coating layer, and the reflective member, an incident light, when reflected, is separated into repeated sequences of red, green, and blue color components and a black matrix segregating the red, green, and blue color components. A sequence of micro-light valves are placed in the path of the reflected incident light to block the undesired color components. The reflective-type diffraction grating structure dispenses with the need for the various layers of color filters.

Abstract: An exposure apparatus includes a first dispersing element for dispersing a substantially parallel laser light, from a laser, with respect to wavelength to provide lights of wavelength units, a first optical system for collecting each light of a wavelength unit from the first dispersing element, a wavelength selecting device for passing a predetermined wavelength region of light, of the lights of wavelength units each being collected by the first optical system, a second optical system for receiving the light from the wavelength selecting device and providing parallel lights of wavelength units, and a second dispersing element for combining the parallel lights of wavelength units from the second optical system, the second dispersing element having substantially the same angular dispersion as of the first dispersing element and a direction of dispersion opposite to that of the first dispersing element.

Abstract: An exposure apparatus includes a first dispersing element for dispersing substantially parallel laser light, from a laser, with respect to the wavelength to provide light beams of wavelength units, a first optical system for collecting each light beam of a wavelength unit from the first dispersing element, a wavelength selecting device for passing a predetermined wavelength region of light, of the light beams of wavelength units each being collected by the first optical system, a second optical system for receiving the light from the wavelength selecting device and providing parallel light beams of wavelength units, and a second dispersing element for combining the parallel light beams of wavelength units from the second optical system, the second dispersing element having substantially the same angular dispersion as that of the first dispersing element and a direction of dispersion opposite to that of the first dispersing element.

Abstract: The present invention provides a method and system for dispersion compensation for a composite optical signal in an optical fiber transmission system. The composite optical signal includes a plurality of channels, each of the plurality of channels includes a band of wavelengths, where the bands of wavelengths have unwanted dispersion and dispersion slope. The present invention includes propagating the composite optical signal in a forward direction; separating the wavelengths in the band of wavelengths in each of the plurality of channels, where the each of the wavelengths in the band is spatially distinguishable from the other wavelengths in the band; spatially separating each band of wavelengths in the plurality of channels; and reflecting the spatially separated bands of wavelengths toward a return direction, where dispersion is added to the reflected bands of wavelengths such that the unwanted dispersion and dispersion slope are compensated.

Abstract: The present invention is a display apparatus that provides protection against damage for a metallic layer. The display apparatus includes a light modulating layer, a polarizer, and a light directing film. The light directing film includes a prismatic structure having two sides, where one side includes saw tooth formations having tilted surfaces and a metal layer on the side of the prismatic substrate having the saw-tooth formations. A tilt angle of the tilted surfaces offsets an optimal viewing angle for the display from a glare angle for the display. In a first embodiment of the invention, the light directing film of the display apparatus further includes an inorganic protective layer formed on the metal layer, wherein the inorganic protective layer inhibits molecular transfer to the metal layer and balances the color of reflected and transmitted light. The light directing film further includes a pressure sensitive adhesive layer between a polarizer and the inorganic protective layer.

Abstract: A method for fabricating light dispersive insulated glazing units is provided. According to this method a substantially sealed integral unit comprising a pair of spaced glazing lites and a heat-shrinkable light dispersive film interposed between the glazing lites and spaced apart from the glazing lites is formed, the light dispersive film being fixed along at least two of its edges with respect to the edges of the glazing lites. The assembled structure is then subjected to a heat treatment for a time and at a temperature sufficient to heat shrink the light dispersive film and cause it to become taut and wrinkle-free.

Abstract: A method and apparatus for multicolor detection employing the natural chromatic aberration of a diffractive microlens to detect two or more colors or light. In the preferred embodiment the diffractive microlens detects two colors in the VLWIR spectral region and is focused on a two-part detector having a central region to detect the shorter bandwidth and a concentrically disposed region to detect the long band, VLWIR radiation. These detectors are arranged in a multicolor focal plane array to allow imaging.

Abstract: In a method and device for removing light by absorption, undesired light is guided by a light entrance aperture into a hollow body having a light-absorbing inner surface. The light which is directed into the hollow body falls onto the reflection surface of a reflector. The reflection surface is configured and positioned in such a way that the light which is reflected back from the reflection surface is not reflected in itself, that only a minor amount of said light does not reach the outside as scattered light via the light entrance aperture and that a substantial amount of the light reaches the inside of the hollow body where it is absorbed. The invention finds particular use in an electronic recording device for point and line elimination of a recording material with a laser beam, wherein an undesired secondary beam is absorbed according to the inventive method in order to avoid disturbing retroreflections.

Abstract: A virtually imaged phased array (VIPA) which receives an input light at a respective wavelength, and produces a spatially distinguishable output light in accordance with the wavelength of the input light. The VIPA has first and second surfaces. The second surface has a reflectivity which causes a portion of light incident thereon to be transmitted therethrough. The first and second surfaces are positioned so that the input light is reflected a plurality of times between the first and second surfaces to cause a plurality of lights to be transmitted through the second surface. The plurality of transmitted lights interfere with each other to produce an output light which is spatially distinguishable from an output light produced for an input light having any other wavelength within the continuous range of wavelengths. A spacer element has an approximately zero thermal expansion coefficient and maintains the relative positioning between the first and second surfaces to be constant.

Abstract: An angular dispersive device acts as a virtually imaged phased array (VIPA) which receives an input light, and produces a spatially distinguishable output light in accordance with the wavelength of the input light. First, second and third lenses are arranged in order to focus the input light into the angular dispersive device. The characteristics of the first, second and third lenses are determined to provide an increased beam width in a top view of the output light produced by the angular dispersive device. The first lens collimates the input light in a side view and has no lens effect in a top view. The second lens receives the input light from the first lens, and focuses the input light in the side view and has no lens effect in the top view. The third lens receives the input light from the second lens, and collimates the input light in the top view and has no lens effect in the side view. The angular dispersive device has first and second surfaces.

Abstract: A virtually imaged phased array (VIPA) which receives an input light at a respective wavelength, and produces a spatially distinguishable output light in accordance with the wavelength of the input light. The VIPA has first and second surfaces. The second surface has a reflectivity which causes a portion of light incident thereon to be transmitted therethrough. The first and second surfaces are positioned so that the input light is reflected a plurality of times between the first and second surfaces to cause a plurality of lights to be transmitted through the second surface. The plurality of transmitted lights interfere with each other to produce an output light which is spatially distinguishable from an output light produced for an input light having any other wavelength within the continuous range of wavelengths. A spacer element has an approximately zero thermal expansion coefficient and maintains the relative positioning between the first and second surfaces to be constant.

Abstract: Disclosed is a tunable multispectral optical apparatus for forming a spectrally processed image of a scene having finite angular extent or alternatively a point source of light, both of which may include multispectral components. A spatial filter is selectively positioned between a hybrid fore-optic and a hybrid reimaging optic, both of which include a diffractive optic. Spectral selectivity is obtained by proper positioning of the spatial filter relative to the intermediate image formed by the hybrid fore-optic before impinging on the hybrid reimaging optic. The tunable multispectral optical apparatus of the present invention may take the form of a bandpass filter or a bandstop filter depending only on the choice of spatial filter--blocking or passing selective wavelength components of the intermediate image.

Abstract: This invention is a light fixture concept using geometrical optical elements and optical diffusors which produce a controlled light beam from a large lighting aperture. The object of this invention is to provide for both low surface luminance of the light fixture aperture and directional control of the light distribution. The geometrical optical elements are placed so as to result in a magnification of the light source, and diffusor elements are used to shape the light beam. A wide range of light sources can be used with this concept. The resulting light fixture will have reduced glare characteristics due both to the decreased luminance of the fixture aperture and to the restricted lighting angle distribution. These light fixtures should find application in a large number of lighting situations.

Abstract: A virtually imaged phased array (VIPA) operating as a wavelength splitter to separate individual carriers from a wavelength division multiplexed (WDM) light. The VIPA has first and second surfaces. The second surface has a reflectivity which causes a portion of light incident thereon to be transmitted therethrough. The VIPA receives an input light at a respective wavelength within a continuous range of wavelengths. The first and second surfaces are positioned so that the input light is reflected a plurality of times between the first and second surfaces to cause a plurality of lights to be transmitted through the second surface. The plurality of transmitted lights interfere with each other to produce an output light which is spatially distinguishable from an output light produced for an input light having any other wavelength within the continuous range of wavelengths.