Abstract: Autofocus apparatus for use in an optical system utilizing a recording medium formed from a birefringent medium and a radiation-sensitive medium. The autofocus apparatus automatically focuses radiation through the birefringent medium and substantially at the interface between the birefringent medium and the radiation-sensitive medium and includes a source of linearly polarized radiation, a quarter-wave plate to convert the linearly polarized radiation to circularly polarized radiation, and an actuator controlled lens for focusing the radiation onto the recording medium, whereby radiation reflected from the first surface of the birefringent medium and the interface between the birefringent medium and the radiation-sensitive medium passes back through the lens and quarter-wave plate and is deflected by a beamsplitter to a polarization detector. The polarization detector isolates polarization components which arise from reflection at the interface and the isolated polarization components impinge upon a detector.

Abstract: A low cost optical system which incorporates a low ultraviolet output tungsten halogen light source and solid state photodetectors and circuitry in such a way as to provide reliable fluorometric test results. The attainment of reliable results using such components is made possible by incorporating highly ultraviolet transmissive optics to maximize ultraviolet light throughput and by using solid state circuitry together with a filter wheel having both light blocking and light passing regions in a manner which fully accounts for noise and dark signals associated with solid state photodetectors.

Abstract: Color film which has relatively high photographic sensitivity, improved spatial sensitivity and reduced problems with aliasing between film stripe structure and scene content and from which full color photographic information can be extracted. An embodiment of the color film includes a black and white photographic film emulsion which is coated upon a substrate, which emulsion is covered with a repetitive pattern of a triad of: (a) color stripes such as yellow, green and cyan stripes wherein at least one of the colors is a nonprimary color; (b) color stripes of unsaturated hues such as, for example, pastel yellow, pastel green and pastel cyan stripes wherein at least one of the colors is a nonprimary unsaturated hue; or (c) color stripes of unsaturated hues of any color. Full color prints or enlargements are made by a hybrid process which includes electronic scanning to extract color information and an optical or an electronic method to extract detail information.

Abstract: A low cost optical system which incorporates a low ultraviolet output tungsten halogen light source and solid state photodetectors and circuitry in such a way as to provide reliable fluorometric test results. The attainment of reliable results using such components is made possible by incorporating highly ultraviolet transmissive optics to maximize ultraviolet light throughput and by using solid state circuitry together with a filter wheel having both light blocking and light passing regions in a manner which fully accounts for noise and dark signals associated with solid state photodetectors.

Abstract: Zooming optical systems in which the effective focal length changes required for changing image scale and focus maintenance are brought about by movement of various system elements across the optical axis rather than along it as is the usual case. The zooming systems are suitable for use in a variety of applications including visual instrumentation and photographic systems.

Abstract: Optimal sum-frequency and second harmonic generators are fabricated in ferroelectric waveguides by taking into account the interference between generated beams of Cerenkov radiation.

Abstract: The structure of a miniature component for use in connecting optical fibers along with methods for fabricating the component. A small scale tube having precision surfaces inside and out has formed directly in it a converging, preferably plastic, lens capable of imaging a fiber end properly located into assimilarly situated fiber in another like facing component. The outside precision surfaces of the tube serve as references for precision alignment of the component while its inside precision surfaces aid in formation of the lens.

Abstract: Apparatus for providing self-organized, phase-matched harmonic generated radiation which includes a single-mode fiber doped with ytterbium or ytterbium-aluminum which is placed in a laser cavity having a mode-locking and a Q-switching apparatus.

Abstract: A method for fabricating buried waveguides on a glass substrate which contains sodium ions includes the steps of masking the substrate, performing a field-assisted ion-exchange process at low temperature to form waveguides by exchanging silver ions for the sodium ions, and performing a field-assisted ion-exchange at low temperature to bury the waveguides by exchanging potassium ions. In a preferred embodiment, the silver ions and the potassium ions are exchanged from eutectic melts.

Abstract: An integrated optics print head includes an array of indepenedently driven semiconductor lasers disposed on a common substrate with their outputs coupled to an integrated waveguide structure. The integrated waveguide structure includes a multiplicity of "S" shaped, low-loss waveguides which have substantially the same length. Further, in order to reduce crosstalk, the region of the waveguide structure at the output where all the waveguides are in close proximity is made as short as possible while maintaining a parallel relation between the waveguide outputs.

Abstract: An external light modulator which relies on efficient changes in electro-optic coupling of light between copolarized guided modes in a single waveguide channel formed in a lithium niobate or lithium tantalate substrate by proton exchange with benzoic acid.

Abstract: A hologram is fabricated by opening a volume phase reflection hologram formed in a recording medium such as a positive photoresist. The opening occurs by forming a second hologram, such as an off-axis hologram, in the same recording medium. The opened hologram can be replicated in metal and the metal can be used to emboss the fringe pattern of the opened hologram into plastic. A full range of colors in the visible spectrum may be obtained by metallizing the embossed plastic structure and then by overcoating it with appropriate clear dielectric layers.

Abstract: A process for forming a channel waveguide in which the channel geometry and the channel index of refraction vary oppositely along the channel length to keep the modal characteristic of the channel uniform uses non-uniform heating of a channel waveguide to cause non-uniform diffusion of the channel dopant. In one embodiment, the channel is passed under a laser at a non-uniform rate to expose the channel to different numbers of laser pulses.

Abstract: Phase array apparatus for use with a lens system to provide a substantially smooth, uniform image of a laser array comprised of a multiplicity of lasers wherein the phase of the radiation emitted by the lasers alternates by an amount which is substantially equal to 180.degree.. The phase array includes: (1) phase means, disposed substantially at a far-field image of the laser array formed by the lens system, which far-field image comprises two prominent lobes, for changing the phase of the radiation in the two prominent lobes by 90.degree.

Abstract: A hologram is fabricated by opening a volume phase reflection hologram formed in a recording medium such as a positive photoresist. The opening occurs by forming a second hologram, such as an off-axis hologram, in the same recording medium. The opening hologram can be replicated in metal and the metal can be used to emboss the fringe pattern of the opened hologram into plastic. A full range of colors in the visible spectrum may be obtained by metallizing the embossed plastic structure and then by overcoating it with appropriate clear dielectric layers.

Abstract: There is disclosed a method of finishing or smoothing the surface of an optical start rod through the use of plasma heat in an atmosphere which prevents contamination of the rod by residual water. Also there is disclosed a method of fabricating an optical waveguide wherein the start rod has deposited thereon silica soot and which is subsequently consolidated by a plasma.

Abstract: A resonant waveguide cavity, preferably a loop, is fabricated from an active material doped host glass and includes a wavelength dispersive lateral coupling designed to preferentially support wavelengths in a selected bandwidth. Pumping light is provided to excite the active material so that the supported wavelengths stimulate in phase emission to increase their amplitude with the amplified signal presented to an output fiber. Where a signal generator is desired, the pumping light can be used to drive the resonant cavity into oscillation to provide a CW output at one of the cavity supported wavelengths.

Abstract: A method for fabricating optical fibers having a rare-earth doped core and a fused silica cladding includes inserting a rare-earth doped soft glass rod into a fused silica tube, the ratio of the outer diameter (OD) to the inner diameter (ID) of the fused silica tube being at least 2 and as large as 50; heating the rod and tube combination in a furnace to selectively volatilize volatile constituents of the soft glass rod which are responsible for the low softening point so that the final composition of the core consists predominantly of SiO.sub.2 and the desired dopants such as rare earths, alkaline earths or other low vapor pressure materials; and drawing the perform into an optical fiber.

Abstract: A preobjective scanning optical system for use with a rotating mirror scanner employing LEDs or lasers to electronically reproduce photographs. The optical system includes a doublet disposed before the mirror and a triplet disposed after the mirror. Instead of collimating, the first optical system along with the mirror forms a virtual, image of the LEDs or lasers which travels along a curved path as the scanner rotates and includes a first and a second lens which, in combination, correct the image for on-axis spherical and axial color aberrations. The triplet has net positive power and its three lenses, in combination, correct for off-axis aberrations such as astigmatism, coma, and lateral color aberration but can be under-corrected for field curvature because its object is the curved virtual image.

Abstract: A hologram is fabricated by opening a volume phase reflection hologram formed in a recording medium such as a positive photoresist. The opening occurs by forming a second hologram, such as an off-axis hologram, in the same recording medium. The opened hologram can be replicated in metal and the metal can be used to emboss the fringe pattern of the opened hologram into plastic. A full range of colors in the visible spectrum may be obtained by metallizing the embossed plastic structure and then by overcoating it with appropriate clear dielectric layers.