Abstract: An improved endoscope comprises an objective including a diffractive optical element juxtaposed to a solid-state imaging element at the distal tip of the endoscope. An inexpensive halogen lamp at the proximal end of the endoscope is employed as the illumination source. A fiber-optic bundle carries light to the distal tip of the endoscope, where diffractive optical elements are provided to disperse light, illuminating the field of view.

Abstract: An apparatus which combines a virtually imaged phased array (VIPA) with a demultiplexer, to provide a large bandwidth, high resolution wavelength demultiplexer. Generally, a VIPA is a device which receives an input light having a respective wavelength within a continuous range of wavelengths, and causes multiple reflection of the input light to produce self-interference and thereby form an output light. The output light is spatially distinguishable from an output light formed for an input light having any other wavelength within the continuous range of wavelengths. The apparatus combines the VIPA with a demultiplexer, such as a diffraction grating. More specifically, the VIPA receives an input light and produces a corresponding output light propagating away from the VIPA. The output light includes a plurality of different wavelength components.

Abstract: An improved auto-focus system for a digital camera has a lens designed to have the focus of two spectra offset from each other by a predetermined amount. The two offset spectra are used to calculate two focus signals. Once the two focus signals are calculated the correct direction to move the lens system to set the optimum focus can be determined.

Abstract: An apparatus which adds "opposite dispersion" to light, to compensate for chromatic dispersion of the light caused by travelling through an optical fiber. The apparatus includes a virtually imaged phased array (VIPA), and a light returning device. The VIPA provides angular dispersion to the light, and the light returning device returns the light back to the VIPA to undergo multiple reflection inside the VIPA. The light returning device is typically a mirror. In this case, the mirror can be shaped so that the apparatus adds a constant dispersion to the light.

Abstract: A high-performance projection optical system uses the multiple spectral peaks of an excimer laser system by using an optical dispersive system to physically separate the broadband laser output into separate narrowband beams which can be used for imaging different substrate surfaces simultaneously. The separated narrowband beams are directed along different optical paths and used to illuminate the object planes of different, identical projection lenses. The projection lenses are designed for the narrowed bandwidth corresponding to one spectral peak of the excimer laser rather than the broadband, multiple-peak laser output This dramatically simplifies both the design and the construction of the projection lens, leading to substantial cost-savings.

Abstract: An apparatus which adds "opposite dispersion" to light, to compensate for chromatic dispersion of the light caused by travelling through an optical fiber. The apparatus includes a virtually imaged phased array (VIPA), and a light returning device. The light returning device is typically a mirror. The VIPA provides angular dispersion to the light, and the light returning device returns the light back to the VIPA to undergo multiple reflection inside the VIPA.

Abstract: A panel unit for use in a window, a partition, a free standing frame, or in a wall, and having a plurality of vertically stacked, elongated transparent elements arranged in a frame, whereby natural light or artificial light on one side of the panel reflects onto the environment on the one side of the panel unit. The reflected light is transmitted through each transparent element and is refracted and dispersed to create a block of color when viewed on the other side of the panel, which results in a color pattern when viewed on the other side of the panel unit. The transparent elements may be made of lead crystal glass or optical glass, and may be triangularly shaped to produce a maximum light dispersion zone or trapezoidally shaped to produce a minimum light dispersion zone. To resist or reduce glare, a shutter apparatus may be mounted adjacent to the panel unit on the side of the panel unit where the direct sunlight exists, or filters or tinted glass may be used.

Abstract: An optical telecommunication system has at least two sources of optical modulated signals at different wavelengths in a predetermined transmission wavelength band, together with a multiplexer for the signals, an optical fiber line connected at one end to the multiplexer, and a demultiplexer/receiver for the signals. The line comprises an optical fiber having a chromatic dispersion value lower than a predetermined value in the transmission wavelength band and increasing as wavelength increases. The fiber also has a zero value of chromatic dispersion at a wavelength lower than the minimum wavelength of the transmission wavelength band by such an amount that no local wavelength zero value of the chromatic dispersion present in the fiber and capable of generating a four-wave-mixing phenomenon is included in the band.

Abstract: An optical system is disclosed for improving the brightness symmetry of a beam emitted from a laser diode where the beam has a large width and a narrow height. The optical system includes a tilt plate for displacing one half of the width of the beam downwardly. A first beam steering prism functions to tilt the remaining, second half of the beam width in a plane parallel to the width dimension so that the second half travels towards the first half. A second beam steering prism is provided to tilt the second half of the beam so that its propagation axis is parallel to the propagation axis of the first half and wherein the second half is stacked above the first half. The optical system functions to improve the brightness symmetry of the beam by a factor of about five. The corrected beam can be used to improve the performance of a solid state laser which is end pumped by a broad area laser diode or a laser diode bar.

Abstract: A planar parallel plate direct vision prism including two glasses for dispersing light as a function of color is disclosed. Also disclosed is an optical system which includes a first optical assembly having two planar parallel plate direct vision prisms for dispersing light as a function of color. The degree and orientation of the light dispersed is controlled by rotating the two prisms of the first assembly in relation to each other and together in unison. A fiber optic bundle transmits the dispersed light and a second optical assembly having two planar parallel plate direct vision prisms recombines the dispersed light emerging from the fiber optic bundle. The degree and orientation of the light recombined is controlled by rotating the prisms of the second optical assembly in relation to each other and together in unison.

Abstract: An achromatic optical system for beam transformation is used for example with the optical head of an optical disk apparatus. This optical system is arranged in an optical path which is traversed by a beam emitted from a light source to reach a surface to be irradiated. This optical system includes a first prism arranged on the side of the light source and a second prism arranged on the side of the surface to be irradiated. The first and second prisms are constructed in such a manner that each of the prisms has a beam incident angle which is greater than its beam exit angle so as to expand the width of a beam passed therethrough and that with respect to a plurality of transmitted beams of different wavelengths the deviation angle of the beam passed through the optical system on the whole (the angle formed by the incident beam on the first prism and the emerging beam from the second prism) becomes the same for each other.

Abstract: Optical apparatus for dispersing a visible light spectrum into primary color bands and directing each color band into a specific pixelated cell of a passive display. The apparatus includes an array of refractive microlenses arranged parallel to the plane of the passive display such as a liquid crystal display and a diffraction grating arranged parallel and in close proximity to the lens array. The microlenses focus visible light onto the display while the diffraction grating separates the visible light into primary color bands in different diffraction orders such that the colors are directed to and transmitted through the corresponding specific pixelated cells.

Abstract: A light exposure and illuminating device in which an outgoing light of an exposure light source is supplied to a light exposure section for illuminating an object to be exposed to light. A moving scattering medium scatters a laser beam outgoing from a laser light source. A light condenser lens condenses the laser beam scattered by the moving scattering medium to a laser beam of a suitable diameter. A plurality of prisms condense the laser light condensed by the light condenser lens as a rectangle of a suitable size on an incident surface of a fly-eye lens. The fly-eye lens uniforms the intensity distribution of the laser beam in cooperation with a folding lens. Another condenser lens radiates the laser beam uniformed in intensity distribution by the fly-eye lens and the firstly-stated condenser lens as a exposure illuminating light on a mask for light exposure on which a light exposure pattern is pre-formed.

Abstract: An optical system is disclosed for improving the brightness symmetry of a beam emitted from a laser diode where the beam has a large width and a narrow height. The optical system includes a tilt plate for displacing one half of the width of the beam downwardly. A first beam steering prism functions to tilt the remaining, second half of the beam width in a plane parallel to the width dimension so that the second half travels towards the first half. A second beam steering prism is provided to tilt the second half of the beam so that its propagation axis is parallel to the propagation axis of the first half and wherein the second half is stacked above the first half. The optical system functions to improve the brightness symmetry of the beam by a factor of about five. The corrected beam can be used to improve the performance of a solid state laser which is end pumped by a broad area laser diode or a laser diode bar.

Abstract: The present invention relates to a method and a device for transmitting images via a transmitting medium, for example, optical fibers, without digitizing images (hereafter called "direct image transmission") and, more particularly, a method and a device for direct image transmission by spectral coding. It is an object of the present invention to provide a method and a device for all optical types of direct image transmission that permits two-dimensional images to be directly transmitted without electrical driving units for scanning or tuning images by distributing light from a point source spectrally so that each pixel in the resulting two-dimensional image corresponds one-to-one with the light having a specific wavelength.

Abstract: An apochromatic grism (42) includes a first prism (48) with a second prism (50) disposed adjacent to it. A grating (44) is adjacent to the front surface of the first prism (48) and the Abbe number and dispersion coefficient of the grating are chosen such that the primary and secondary angular spread for a given spectral band is approximately zero. The apochromatic grism is a simple and compact device with minimal amounts of residual chromatic and anamorphic aberrations.

Abstract: An optical system is disclosed which focuses a polychromatic source to an extended focal pencil. The implementation makes use of two holographic optical elements (HOEs) fabricated and aligned to form a deliberate longitudinal color dispersion, but to alleviate lateral chromatic effects. Consequently, the HOE doublet focuses different wavelengths of the source to different locations along the optical axis. The strong intensity of the focused wavelengths dominate at each location, so that the overall beam has a near-diffraction-limited 1/e.sup.2 spot size and suffers only relatively weak background illumination. An alternative optical system using bulk lenses and several possible applications for the device are also described.

Abstract: A dispersive, optical delay line for frequency modulated light wave pulses, especially laser waves, comprises a first optical grating and a second optical grating that are parallel to each other, separated by a distance d and localized with a pitch a on the surface of a material that has an index N and is transparent to light waves. An incident wave .SIGMA. is diffracted at an angle .theta.' greater than the limit angle of refraction by transmission through the first and second optical gratings, the angle of emergence from the second grating being also equal to .theta.'. The values of the parameters N, .theta.', a and d are chosen so that a variation in delay time .DELTA.t.sub.R of the pulse through the line corresponds to a modulation bandwidth .DELTA.f of the pulse in a quasi-linear domain. Application to compression/expansion to obtain high-power or very short laser pulses.

Abstract: A planar parallel plate direct vision prism including two glasses for dispersing light as a function of color is disclosed. Also disclosed is an optical system which includes a first optical assembly having two planar parallel plate direct vision prisms for dispersing light as a function of color. The degree and orientation of the light dispersed is controlled by rotating the two prisms of the first assembly in relation to each other and together in unison. A fiber optic bundle transmits the dispersed light and a second optical assembly having two planar parallel plate direct vision prisms recombines the dispersed light emerging from the fiber optic bundle. The degree and orientation of the light recombined is controlled by rotating the prisms of the second optical assembly in relation to each other and together in unison.

Abstract: A chromatic dispersion compensation device is provided in the form of an etalon having first partially reflecting mirror providing an input and output port for porting a signal into and out of the etalon cavity. A second partially reflective mirror parallel to and spaced apart from the first mirror, being more reflective than the first mirror provides a monitoring port for monitoring energy within the cavity. Means are optionally provided for controlling a parameter related to the cavity in dependence upon a signal ported from the monitoring port. Means may be provided to control a transmitting laser in dependence upon the signal ported from the monitoring port.

Abstract: A narrow bandwidth bandpass filter having high transmission efficiency for the passband and excellent out-of-band attenuation employs a transmission holographic grating sandwiched between the oblique faces of a pair of right angle glass prisms. An incoming laser beam to be filtered is incident normal to one of the prism faces so as to intersect the holographic grating at about 45.degree.. The grating frequency is such as to diffract light of the transmission wavelength through substantially 90.degree. so that it exits the cube formed by the two prisms from the right angle face of the second prism. The out-of-band wavelengths of the incident beam are either transmitted unaffected through the grating or diffracted at a different angle than the light of the transmission wavelength.

Abstract: Dispersive microlens apparatus and methods are used in one mode for detecting multiple, different wavelengths from a bandwidth of wavelengths (existing within an image plane blur spot) and are used in another mode for combining a plurality of different, emitted wavelengths into a bandwave of wavelengths (at a blur spot in an image plane).

Abstract: A temporal imaging system is presented consisting of a dispersive input path, a phase modulator producing a phase modulation substantially equal to A+Bt.sup.2, and an output dispersive path. This temporal imaging system can be combined with other temporal lenses to image input signals in the same manner that spatial lenses can be used to image light from spatial sources. In particular, this temporal imaging system can be used to expand, compress and or invert input temporal signals.

Abstract: An Echelle polychromator 50 has disposed upstream thereof a pre-monochromator 14 comprising a prism 20. The linear dispersion of the pre-monochromator 14 is variable by varying the angular dispersion of the prism 20. A particular spectral position and the close vicinity thereof are analyzed by an Echelle grating 54 with high resolution. Care must be taken that, on the one hand, the detector array 66 of the Echelle polychromator 50 is fully exploited in response to the central wavelength respectively observed and that, on the other hand, interfering orders are kept away from the Echelle polychromator 50. The linear dispersion of the pre-monochromator is variable for this purpose.

Abstract: Apparatus for producing color effects includes a source of polychromatic light, a transparent linear-polarizer medium located to receive the polychromatic light and to output linearly polarized light, a transparent phase-rotating dispersive medium located to receive the linearly polarized light and to rotate the angle of polarization thereof as a function of wavelength to thereby produce color separation of the polarized light, and a transparent linear-analyzer medium located to receive the light from the dispersive medium at a selected angle to output a selected color thereof.

Abstract: The invention relates to optical elements, particularly retro-reflecting, retro-imaging and optical transmission inversion elements to relay a true scale equal conjugate image of a scene. Hitherto, the image had a resolution limit set by the pitch and/or packing density of micro-optical elements to reflect or transmit ray bundles impinging on them, the number of elements within the viewing zone determining the lateral and hence depth resolution in any given direction. The object of the invention is to reduce the effect of micro-screen texture in a relatively inexpensive manner, that provides real-time systems and which can be used with fast moving objects. This objective is met by an optical element comprising a retro-reflecting or auto-collimating transmission screen (9) having one or more lenses (6,10) and an associated means (8,11) of displacing wavelengths to different degrees and whereby to spread a reflected or transmitted image into a spectral streak.

Abstract: A device for use in a system of hologon deflection of a laser beam having a wavelength .lambda. at a rotating angle .theta..sub.R to produce a scan line. The device comprises a prism having a grating on at least one surface. The prism is positioned to deflect the scan line after hologon deflection of the laser beam. The prism has an apex angle between scan line intersecting surfaces of .theta..sub..alpha.. The grating has a grating spacing D. Deflection of the scan line by the angle .theta..sub..alpha. is designed so that it is equal to the deflection of the scan line by the grating. This produces a scan line having bow of less than 1/600 of the bow of the scan line without the prism and effectively eliminates wobble. The range for the apex angle .theta..sub..alpha. may be from about 1.degree. to about 30.degree., and preferably from about 2.degree. to about 6.degree.. The grating spacing ranges from about 0.0001 to about 0.001 millimeter.

Abstract: To obtain light-diffusing polycarbonate resin compositions which show excellent light diffusing characteristics while maintaining the impact strength and other inherent properties of the matrix resin.Resin compositions in which certain light-diffusing fine particles are added and dispersed in 100 wt. parts polycarbonate resins.

Abstract: A single-grating method and apparatus is described for a laser pulse stretcher and compressor. The method and apparatus exploits a two-layer vertical structure. One layer for the stretcher, and the other, for the compressor. Such a stretch-compressor is particularly suitable for using in a chirped-pulse or regenerative laser amplifier where laser wavelength tuning is desirable. When a change in the wavelength is applied, only one rotational adjustment is required to resume the alignment of the whole stretcher and compressor. This apparatus shows significant simplification in structure and alignment over the existing stretcher and compressor systems.

Abstract: A projection exposure apparatus that provides uniform illumination with at least partially incoherent light that could produce interference fringes. The projection exposure apparatus includes a light source emitting at least partially coherent light, a dispersion element for dispersing the light according to wavelength, a dividing element for dividing the dispersed light into plural light beams, a condenser unit for introducing each of the plural light beams in an overlapping manner onto a mask including circuit patterns, and a projection lens unit for projecting the light passing through the mask onto a surface of a wafer.

Abstract: A reflector has a body of a ceramic oxide superconductive material whose surface is treated to be diffusively reflective and is coated with diamond-like carbon or magnesium fluoride.

Abstract: An optical element (10) is provided with a coating so as to selectively pass spectral lines of interest. The element includes a substrate (14) having a first major surface and a second, opposite major surface. The element further includes a coating, preferably a rugate coating (12), formed upon at least one of the major surfaces. The rugate coating has a spatially varying index of refraction profile through a depth thereof. The profile is selected so as to provide the element with a prescribed dispersion characteristic that matches a dispersion characteristic of a source of the radiation signal.

Abstract: This invention provides embodiments of etalons (10, 14, 18, 22) that eliminate or minimize a falloff of relative radiation modulation as a function of wavelength or FOV. A first embodiment employs a dispersive coating, such as a rugate (12a, 12b, 16), to correct for the phase shift across an etalon step. A second embodiment employs a dispersive coating, such as a rugate (20a, 20b, 24), that provides a stepless etalon in which the phase shifts are generated by the coating. It is shown that in a rugate the phase shift on reflection is directly related to the phase of a sinusoidal index of refraction profile within the rugate, while the frequency of the sinusoidal index of refraction profile determines the wavelength at which the phase shift occurs. By changing the phase of the sinusoidal index of refraction variation as the period of the sinusoidal index of refraction variation is changed, a phase shift of incident radiation is produced that is a function of the wavelength of the incident radiation.

Abstract: The optical device can examine a spectrum at low resolution and subsequently choose a portion of that spectrum to be examined at higher resolution, using a single detector array for both spectra. The latter spectrum can be chosen to be arbitrarily anywhere within the low resolution spectrum. The device comprises a source of input light, a wedged shaped dispersive device, a first reflective mirror, a second reflective mirror, a RF generator connected to the dispersive device, and a detector array. In operation, the dispersive device provides a low dispersion spectrum in the zero order light when the source of light is impinged upon it. When the RF generator is turned on, a second spectrum which is diffracted is obtained. This will be the high resolution spectrum. By operating near 100% diffraction efficiency, it is possible to switch from one spectrum to the other. By adjusting the RF frequency the band center of the high resolution spectrum can be varied to fall anywhere within the low resolution spectrum.

Abstract: A device for projecting a rainbow-like spectral display including a housing provided with a projecting arrangement for projecting the rainbow-like spectral display onto a viewable surface. The projecting arrangement includes segments, each segment including a light emitting source for producing light rays, and a diffraction member such as a prism for effecting a spectral dispersion of the light rays for projecting same to produce the rainbow-like spectral display. Preferably, each segment also includes a convergent or convex lens disposed between the light emitting source and the diffraction member, and a reflector covering a rear portion of each light emitting source. The housing could be portable, battery operated, and in the form of a casing provided with a hinged cover.

Abstract: For use, e.g., in the compensation of frequency dispersion in the course of transmission of an optical signal, a pulse-shaping device is provided with a suitably shaped nonplanar mirror (16). When spatially spread-out frequency components--produced, e.g., by a grating (14)--are reflected from such mirror, a frequency-dependent phase shift is introduced; for example, such phase shift may be a third-order function of frequency. Upon recombination of frequencies, a shaped pulse is obtained. Furthermore, third-order compensation can be used to compress amplified light pulses, e.g. as produced by a semiconductor gain medium (80, 81).

Abstract: A stereoscopic tandem scanning reflected light confocal microscope employs longitudinal and transverse chromatic aberration in conjunction with color dispersion prisms in a binocular eyepiece assembly to provide a three dimensional vertical view through a specimen.

Abstract: This invention is directed to an optical instrument including a prism and a convex reflective surface for producing artificial rainbows which is used for a display in halls of entertainment as well as in shops and for interior decoration. Comparatively small optical instruments can also be used as a toy.

Abstract: An optical filter having a variable spectral transmittance function of selectable shape is described which includes a spectrum forming element for dispersing a light beam into a characteristic spectrum, an optical system for forming an image of the spectrum and directing the image into a multi-element electronic spatial light modulator, such as a liquid crystal display or electrophoretic display, and an optical system for projecting the spectrally filtered light as a directed beam.

Abstract: A solar powered ornamental light pattern producing device which produces visually pleasing patterns of light, composed of a housing, a pair of photo-voltaic devices connected with the housing, a shaft rotatably connected with the housing and rotated by the photo-voltaic devices, a pedestal connected with a distal end of the shaft, a flat mirror located on the pedestal, and a multi-faceted crystal which is located upon the flat mirror. When sunlight strikes the solar cells of the photo-voltaic devices a mechanical linkage with the photo-voltaic devices causes the shaft to rotate. As the shaft rotates, the various facets of the crystal are rotated, causing sunlight reflected off the mirror and interacting with the crystal, and sunlight directly interacting with the crystal, to be refracted and reflected into a whole host of pleasing patterns and colors.

Abstract: An optical pulse compressor having a single deflecting dispersive optical element in the form of a diffraction grating (10) or prism for temporal compression of an optical pulse, the frequency of which increases during the pulse duration. An elongated target (T) for receiving the compressed pulse is arranged in parallel with an output surface of the grating or prism. To increase the inclination of the pulse front for effective synchronous travelling wave excitation of the target the output surface of the diffraction grating or prism can be interfaced by an immersion medium or the beam path can be made to converge in the plane containing the target by a cylindrical lens or a reducing imaging optical system can be arranged between the grating or prism and the target.

Abstract: A color separation optical system includes a set of prisms which separate incident light into components having different wavelengths. Image pickup devices may be exposed to the separated light components. An arrangement prevents or reduces the influence of a temperature variation upon color separation characteristics. The color separation optical system may be manufactured in a new way.

Abstract: An image sensing apparatus of the type employing resolving and sensing means is provided with sensing means of selected size and geometry to allow approximation of arbitrary filter response. The sensing means of selected size and geometry may be incorporated into compact, self contained image resolving and sensing apparatus having a transparent substrate for resolving an incident image by refraction, diffraction or other suitable mechanism. The sensing means may be located directly on a surface of the transparent substrate. Logic and select circuitry may be integrally and simultaneously formed with the sensing means. The size and geometry of the sensing means may enable approximation to color inhibition and other effects to allow approximation of the spectral response of the human eye.

Abstract: A compact, self contained image resolving and sensing apparatus of the type used in electronic imaging applications includes a plurality of sensing devices such as photodetectors formed on a transparent substrate capable of resolving a polychromatic image incident thereupon. The mechanism by which the substrate resolves the incident image may be refraction, diffraction or other suitable mechanism. The sensing devices are sized and located on the substrate such that they are capable of detecting one or more wavelength components of the resolved polychromatic image. Logic and select circuitry may be formed on the substrate generally contemporaneously and of similar materials as the sensing device.