Abstract: An interference filter (10, 30, 50, 70, 90, 110, 130, 150, or 190) filters selected wavelengths by dividing an input beam into two or more intermediate beams having different optical path lengths and by recombining the intermediate beams into an output beam that is modified by interference between the intermediate beams. An optical path length difference generator (20, 40, 60, 80, 100, 120, 140, 160, or 200) varies the optical path lengths of the intermediate beams by changing the physical lengths of their paths or the refractive indices of the mediums in which they are conveyed. The optical path length generator (20) of one exemplary embodiment (10) includes a spacer plate (20) that is divided into elements (22 and 24) having different refractive indices for varying the optical path lengths of the intermediate beams.

Abstract: A holographic grating is written into a photorefractive erasable holographic member and a light beam having a first wavelength which includes the joint power spectrum of a pair of joint images to be correlated is directed at the photorefractive member to partially erase the grating. A phase conjugate signal from the partially erased grating is then readout and Fourier transformed to produce the correlation output spots.

Abstract: An autostereoscopic display apparatus includes a matrix display panel (10), preferably an active matrix liquid crystal display panel, having display elements (12) in rows and columns and arranged in groups of at least three adjacent display elements, and an optical director (15) in the form of, for example, a lenticular screen overlying the panel (10) and having lenticules (16) extending in the column direction with each lenticule overlying an associated display element group, in which adjacent display elements in a group are arranged so as to partly overlap one another in the column direction (Y). The display elements in a group can, for example, be arranged in a line in the row direction (X) and shaped as non-rectangular parallelograms, or triangles, successive ones being inverted, or interdigitated, or arranged in two or more rows.

Abstract: Photoresponse from a ferroelectric optical computing device, such as a memory cell or a logic switch, is increased by either illuminating the regions of the ferroelectric crystal under the electrode edges in a sandwich structure device or by aligning the principal axis of the ferroelectric crystal parallel to the linear polarization vector of the optical beam. Device density is increased by reducing the beam size using a small near-field optical fiber. Device evaluation including imprint failure susceptibility is performed by illuminating each ferroelectric optical computing device in a large array of such devices and storing the device address of any device whose response departs from a normal range.

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: An encoder has the capability of outputting a stable displacement signal with small distortion. The encoder includes a first scale and a second scale. The first or second scale has a scale pattern in which pattern elements are arranged in such a manner that the spacings between adjacent pattern elements are not constant but vary in phase relative to the reference phase of a reference pattern element by amounts of P/(2.multidot.L), P/(2.multidot.m), P/(2.multidot.n), P/(2.multidot.o), . . . (L, m, n, o, . . . are positive integers, P is the mean pattern period) and by amounts of combinations of sums of these values.

Abstract: The present invention relates to a multi-layer dielectric bandpass filter having a primary and a secondary passband. A secondary passband outside the reflection zone of the primary passband is optimized to reduce ripple achieving a passband of at least 90% transmission. Optimization comprises modifying the thickness of certain quarter wavelength reflector layers of a single passband filter from true quarter wavelength at the primary passband to non-quarter, or non-integer-multiple quarter wave thickness.

Abstract: Light dispersive insulated glazing units are disclosed. The light dispersive insulated glazing units comprise two lites of glazing material, spaced apart from and opposing one another and a visible light dispersive film, such as a hologram or diffraction grating, interposed between confronting surfaces of the lites. Methods for producing these light dispersive insulated glazing units are disclosed, as well.

Abstract: Coma of an objective lens occurs depending on the lens-forming condition when plural disks of different substrate thickness are recorded and reproduced. An objective lens according to this invention is not influenced by the coma even if the thickness of the substrates is changed. For this purpose, a diffraction grating whose aberration is corrected is formed on the first side of an aspheric objective lens. Due to this correction, light beams having different diffraction orders, e.g. 0th order diffracted light and +1st order diffracted light, are focused respectively on two kinds of substrates of different thickness. The whole objective lens is tilted to correct its axial coma, and the tilt angle is predetermined to be substantially identical with respect to plural substrates which are different in thickness.

Abstract: A zoned lens comprises at least two adjacent zones (16) formed such that the differences between the optical path lengths between an object point and a pixel of light beams extending through these two adjacent zones (16) of the lens (15) are at least equal to half the coherence length of the light used, preferably at least equal to the coherence length of the light used.

Abstract: Systems for three-dimensional viewing aimed at full-color flat-screen binocular stereoscopic viewing without the use of eyeglasses for the viewer. According to the invention, light emanating from a display presenting a left image and a right image is directed only to the appropriate left or right eyes of a viewer using various combinations of light polarizing layers and layers of light rotating means.

Abstract: A method for pattern recognition and localization using a joint transform correlator and joint transform correlator. The method includes providing a joint image of a reference image and an input scene image at the input plane of the correlator, receiving the joint image and providing a Fourier transform interference field of the reference image and the input scene image, receiving the Fourier transform interference field and providing a joint power spectrum, compensating for noise prevailing within the input scene image by processing the joint power spectrum to produce a noise compensated joint power spectrum, and receiving the noise compensated joint power spectrum and providing a noise tolerant correlation signal so as to enhance pattern recognition and localization capabilities.

Abstract: An optical device for generating a signal based on a distance of an object from the optical device. The optical device includes a first polarizer, a birefringent crystal positioned optically downstream from the first polarizer, and a second polarizer arranged optically downstream from the birefringent crystal. The second polarizer creates a pair of interferograms by adjusting a phase of the light. Two outputs are generated by separately integrating an amount of light of at least a part of each of the pair of interferograms. Finally, the two outputs are combined such that the signal, depending only on the distance between the object and the optical system, is obtained.

Abstract: A phase-only filter for approximating a given optical transfer function for monochromatic incoherent light. The filter is designed by solving an integral equation for a phase function, and imposing, on a transparent plate, an optical path length for the incoherent radiation equal, in radians, to the phase function modulo 2.pi. plus an overall constant.

Abstract: An all optical photorefractive holographic joint transform correlator provides a first correlation plane output port using two-beam coupling, and a second correlation plane output port employing four-wave mixing. With appropriate input beam intensity ratios, the first port output is capable of high discrimination, while simultaneously the second port offers a low discrimination output.

Abstract: A radiation apparatus comprising a radiation source and a filter arranged in an optical path, said filter comprising two transparent filter discs which are arranged substantially in plane-parallel fashion relative to each other and which are held with their surrounding edges in a frame made of a material of good heat conduction, the filter discs and the frame defining a closed cavity which has provided therein a medium for selectively influencing the radiation spectrum. The frame is divided substantially in a direction transverse to the filter axis into first and second frame halves in such a manner that the one filter disc is arranged on the first frame half at the side facing the cavity and the other filter disc is arranged on the second frame half at the side facing the cavity.

Abstract: An optical prism having a first glass member which has a first surface on which an specific light is irradiated, a second surface which reflects a part of the specific light and passes through the rest of the specific light, and a third surface on which the part of the specific light reflected by the second surface is irradiated in a substantially vertical direction; and a second glass member which has a fourth surface which passes through the rest of the specific light passing through the second surface, and a fifth surface on which the rest of the specific light passing through the forth surface is irradiated in a substantially vertical direction; wherein the third surface and the fifth surface have a resin which hardens by being irradiated the specific light.

Abstract: A color selective, anti-reflective optical coating has a substrate (42), a first layer (44) and a second layer (46). The first layer (44) has an index of refraction that is 25% to 39% greater than an index of refraction of the substrate (42). The first layer (44) has a width of between 12.31 nanometers and 13.41 nanometers. The second layer (46) has an index of refraction that is between 1% and 17.5% less than the index of refraction of the substrate (42). The second layer (46) has a width between 118.32 nanometers and 130.78 nanometers. When the color selective, anti-reflective optical coating is applied to a head lamp lens (40), it significantly increases the output of the head lamp (20) and has a distinctive tint.

Abstract: A miniaturized fingerprint sensor has a holographic phase grating glued to a base surface of a trapezoidal prism which operates on light totally internally reflecting from a finger-coverslip interface protecting the exterior surface of the grating, diffracting the reflected light to propagate back through the base surface and out the top parallel surface of the prism in a converging beam having an optical axis normally oriented (.perp.) with respect to such parallel base and top surfaces of the prism. A mirror folds the emerging converging light beam directing it into a camera system. The converging light beam emerging from the top surface of the trapezoidal prism contains high contrast, detailed images of ridges, valleys and pores of a finger-surface interface oriented in a plane normal to the optical axis.

Abstract: An image stabilizing apparatus for correcting a blur of image by using correcting optical means supported in a manner capable of relative displacement in relation to the lens-barrel is adapted to include: detection means for detecting the state of the relative displacement of the correcting optical means in relation to the lens-barrel; amplifier means for amplifying the output of the detection means at an amplification degree corresponding to the state of the relative displacement of the correcting optical means in relation to the lens-barrel; and judging means for judging the state of the relative displacement of the correcting optical system in relation to the lens-barrel in response to the output of the amplifier means.