Abstract: A broadband diffractive lens or imaging element produces a sharp focus and/or a high resolution image with broad bandwidth illuminating radiation. The diffractive lens is sectored or segmented into regions, each of which focuses or images a distinct narrowband of radiation but all of which have a common focal length. Alternatively, a serial stack of minus filters, each with a diffraction pattern which focuses or images a distinct narrowband of radiation but all of which have a common focal length, is used. The two approaches can be combined. Multifocal broadband diffractive elements can also be formed. Thin film embodiments are described.

Abstract: A holographic recording of the interference between an object laser beam and a reference laser beam is used to combine the amplitudes of multiple laser beams which are conjugates of the reference beam into a single laser beam which is conjugate of the object beam. An optical device in the form of a prism has an entrance face with a diffusion surface, and an exit face with a light sensitive recording medium. An object beam incident on the diffusion surface is scattered over the recording medium, in interference with a reference beam simultaneously incident at an angle .theta. onto the same medium. Multiple beams, conjugate to the reference beam, incident at angles .theta..+-.4.degree. on the hologram thus created on the recording medium are diffracted by the hologram and caused to combine at the diffusion surface to form a signal output beam, conjugate to the original object beam and having an amplitude which is proportional to the sum of the separate amplitudes of the combined beams.

Abstract: A thin plastic sheet having a reflective material on one surface. Sandwiching the reflective layer is an environmental protective coating of plastic resin. In the preferred embodiment, this protective coating also functions as an adhesive for face bonding the film to a mirror frame. In an alternate embodiment, the protective coating is positioned at the reflective surface and an additional adhesive is preferred. This film construction provides a first surface mirror without the disadvantages of prior mirrors. A method of making a mirror is also disclosed.

Abstract: An anti-reflective coating employing Si.sub.1-x H.sub.x as a high refractive index material in a film pair together with SiO.sub.2 as a low refractive index material is found to be substantially transparent to visible light and to provide good anti-reflectance where the Si.sub.1-x H.sub.x film is ultra-thin, preferably less than about 80 Angstroms, and the thickness of the SiO.sub.2 film is matched to that of the Si.sub.1-x H.sub.x film. Laminated glazing units having such anti-reflective film can be used, for example, even in applications requiring high transmittance of visible light, such as motor vehicle windshields, in view of the substantial transparency of the coating.

Abstract: Applicant has discovered a method for microembossing reflector surfaces with controlled reflecting patterns too small to be resolved by the unaided eye but capable of providing controlled reflection characteristics superior to uncontrolled random deformation. The result is a microtextured reflector of having dispersion characteristics of enhanced uniformity and a display device which can be read over an enhanced range of viewing angles. Specifically, a reflector in accordance with the invention comprises a base plane and a pattern of microelements having maximum lateral dimensions less than 125 micrometers and smooth, continuous mold-formed surfaces arising from the base plane. Such a reflector surface can be made using a master formed by covering a substrate with photoresist, exposing the resist to define a pattern of microelements having maximum lateral dimensions less than about 125 micrometers and heating the substrate to partially melt the resist elements thereby obtaining smooth-surfaced microelements.

Abstract: A wavelength-selective phase-grating optical low-pass filter has a phase difference structure formed at a boundary face between two layer materials which have different refractive index distributions and an identical refractive index at an intended wavelength. A trapezoid form is adopted at the phase difference section of the phase grating to achieve an excellent MTF characteristic in the condition of: ##EQU1## thereby obtaining a wavelength-selective phase-grating optical low-pass filter capable of adjusting the cutoff characteristic and improving the characteristic in the low-frequency region of the spatial frequency.

Abstract: A terminator system particularly suited for beams of high intensity electromagnetic radiation such as from a laser includes an enclosure having a hole therein and a black mirror mounted in the enclosure. The black mirror has a specularly reflecting surface opposite the hole and is oriented at an angle such that the beam impinging on the hole would be impinging on the specularly reflecting surface and would not be reflected directly back out the hole. The black mirror is constructed of a material that absorbs energy at the wavelength of the incident beam. In another preferred embodiment, there are a plurality of black mirrors for performing a succession of reflections, so that the beam power is reduced significantly at each reflection.

Abstract: A pattern recognition apparatus and a method for operating same. The apparatus includes a volume holographic medium (4) having a plurality of Fourier-space volume holograms representing pattern templates stored within. The apparatus further includes a spatial light modulator (1) and a phase encoder (2). The phase encoder has an output optically coupled to the medium by a first Fourier transform lens (3). The spatial light modulator spatially modulates a spatially uniform laser beam (7) in accordance with an unknown pattern. The two-dimensional phase encoder causes the spatially modulated laser beam to be spatially distributed prior to application to the medium. The apparatus further includes a detector (6, 11) having an input optically coupled by a second Fourier transform lens (5) means to an angular spectrum of plane waves generated by the medium in response to the output of the spatial modulator, phase encoder, and first Fourier lens.

Abstract: This invention is a trailer hitch viewing device which attaches to the front of a trailer and assists the driver of the tow vehicle to connect a trailer to a tow vehicle. The device is designed so that, after initial installation and alignment of the mirror, the mirror can be easily detached by merely lifting it out of an anchor bracket. The mirror is designed to be removed after the trailer hook up has been successfully achieved and to be folded in the center to form its own protective storage and carrying case. After storage, the mirror can be replaced for subsequent use by merely lowering it into the anchor bracket. Because of the unique design of the anchor bracket, mirror and other mounting hardware, the mirror does not require realignment when replaced and the device is immediately ready for use as soon as the mirror is placed in the anchor bracket.

Abstract: An optical correlator system for encoding a complex optical image onto a erent beam of light such as a laser and comparing it with a reference complex image. One embodiment of the invention encodes phase only information of the complex image onto the coherent beam of light by means of a liquid crystal television receiver. The light beam is passed through the liquid crystal television receiver, whose pixels are manipulated to provide phase information concerning the image. A second embodiment of the invention encodes both phase and amplitude components of a complex image onto the coherent beam of light such as a laser beam. Either or both encodings are utilized in the optical correlator system.

Abstract: The invention relates to a method for the photographic recording and the visual restitution of a tridimensional scene by means of a coherent light source (1). According to the invention, in view of the photographic recording, a coherent light beam is projected onto said scene such that it illuminates only a small portion of the surface of the scene (3) and a photosensitive recording plate (4) is disposed in such a way that it receives diffuse light coming from said scene; in view of the visual restitution, a first face of said plate is illuminated by a coherent light beam while the second face of said plate is observed.

Abstract: A reflecting surface which is open at least at one axial end and in an axial section conforms to an axial section through a geometric surface generated by rotating a parabolic curve about an axis normal to the parabola axes. An elongated source/sink extends along the axis of the reflecting surface and is at least partly enveloped by that surface.

Abstract: A pattern ERG (PERG) projector (FIG. 2a) includes a coherent light source (32) for generating a projection beam, modulation optics (34) for modulating the projection beam with an alternating ERG interference pattern (with a selected spatial and alternation frequency), segmentation optics 35 for selectively segmenting the ERG interference pattern, and wide-angle imaging optics (36) for focusing the projection beam such that it passes through the pupil, and then diverges to project onto the entire retinal field-of-view, including the anterior retina out to the far periphery. A PERG testing program can be used to selectively probe the entire retina and develop a retinal map--PERG data has been correlated with retinal ganglion cell viability, and is therefore useful in diagnosing and monitoring retinal degeneration caused by glaucoma and other diseases.

Abstract: A system for correcting wavefront distortion includes an eight channel deformable mirror 11 attached to a two-axis, tip/tilt mount 12. The deformable mirror 11 reflects an incoming telescopic wavefront 10 onto a beamsplitter 14. The beamsplitter 14 divides the reflected telescopic wavefront 13 into two separate beams 15, 20. The beam 20 reflected by the beamsplitter 14 may be used for experimentation and measurement. The beam 15 transmitted by the beamsplitter 14 is directed toward a modified Hartmann-Shack wavefront sensor 16. The modified Hartmann-Shack sensor 16 detects the slope of the wavefront at several locations across this transmitted beam 15 and provides analog signals 17 representing these slopes to a series of actuator drive circuits 18. The actuator drive circuits 18 provide excitation signals 19 to actuators 22, 30 on the deformable mirror 11 and the two-axis, tip/tilt mount 12.

Abstract: A cylindrical lens and a binary optical element for collimating with low optical aberrations an asymmetrically diverging input wavefront. The binary optical element is formed on a planar substrate on which a binary optical diffraction pattern is etched on the front surface thereof. The binary optical diffraction pattern is designed such that each ray of light from the diverging input light source will travel the same optical path length or vary from that optical path length by an integer multiple of the wavelength of the light in travelling from its source to its exit from the front surface of the binary optical element. A beam angle alignment element is also provided, to be utilized in conjunction with a cylindrical lens and the binary optical element, for correcting angular misalignments of diode lasers whose output wavefront has an optical axis which is either above or below the plane in which the active region is formed.

Abstract: The invention relates to an outside rear viewing mirror of the type wherein a mirror head assembly is supported upon and rotated relative to the support arm to permit normal adjustment of the rear viewing field of vision and further which includes a mechanism for adjusting the lateral or axial position of the mirror head assembly along the support arm when the mirror head assembly is rotated to a forward facing, non-viewing position relative to the support arm.

Abstract: A near-real-time holographic display for operations at a remote work site where a three dimensional database is collected with a laser range scanner. The database is then divided into discrete two dimensional segments or depth planes. A holographic recording material is then sequentially exposed to multiple depth planes through a stack of three spatial light modulators in a multiplane exposure process. This procedure is repeated for all depth planes in the database. The holographic recording material is then rapidly developed for viewing of the remote work site in a holographic image that simulates natural vision.

Abstract: A light-weighted optical assembly is provided. The light-weighted optical assembly of the invention is comprised of two members. Each member is constructed of a section and a plurality of ribs extending from the section and comprises one-half of the total thickness of the optical assembly. The members are fused at second ends of the plurality of ribs in a crossing, abutting manner. It is the crossing, abutting fusion of the two members which maintains the rigidity and stiffness of the optical assembly so as to insure against deflection of any reflective surface.

Abstract: A multidimensional, visually readable, diffractive surface grating such as a hologram is reproduced by providing a master grating, generating a negative image plate from the master grating for insertion into a forming device, and replicating the master grating in plasticizable material in the forming device so as to provide a directly visually readable grating.

Abstract: A technique for all-optical Code Division Multiple Access (CDMA) system based on optical holography is disclosed. In this technique the energy of an incoming information light signal is spread over a spatial domain by a two-dimensional spatial encoder which includes a mask having regions of first and second transmission characteristics corresponding to the unique code assigned to a particular source. Subsequent decoding, which is accomplished by an optical matched filter through the use of a hologram, spatially despreads the energy of the information light signal and produces a focused light beam which serves as input to a code division detector.