Abstract: A method of etching silicon with a laser at a very fast rate of the order of 45 microns/second includes the steps of providing an atmosphere of sulfur hexafluoride about the silicon and directing a continuous laser beam having a wavelength of about 0.6 or less microns at said silicon.

Abstract: A phase-sensitive ultrasonic modulation method for the detection of strain-sensitive spectral features involves the use of an ultrasonic field with well-defined wavefronts and a light beam of spot size less than the ultrasonic wavelength and of linewidth less than that of the spectral feature. When the light wavelength coincides with the wavelength of the spectral feature, the ultrasonic wave shifts, splits, or broadens the absorption lineshapes of the various centers contributing to the spectral feature thereby changing the amplitude or phase of the light beam or emitted fluorescence in synchrony with the ultrasonic field.

Abstract: A brightfield/darkfield microscope illuminator has two axicon mirrors and a third plane mirror for use with two light beams from different sources. An open shutter positioned in the path of one beam provides brightfield illumination. An open shutter positioned in the path of the other beam provides darkfield illumination. This illuminator easily switches between operation in the darkfield and brightfield modes, uses substantially all the light in one beam for darkfield illumination and easily balances the illumination between the two light sources.

Abstract: The orientation of the alignment layer in a raster-scanned thermally addressed smectic liquid crystal display device can be chosen relative to the writing orientation to accentuate a selected characteristic. A perpendicular alignment with respect to the scan direction produces uniformly written images in both scan directions to allow high quality bidirectional writing. In a preferred embodiment the liquid crystal cell includes a liquid crystal material comprising 4-octyloxy-4'-cyanobiphenyl 37.5%, 4-decyl-4'-cyanobiphenyl 36.8% weight percent and 4-undecyl-4'-cyanobiphenyl 25.7 weight percent.

Abstract: A method and device for detecting a narrow acoustic spectral feature in a sample as described. The method uses an electrical frequency modulated (FM) signal that is obtained from a voltage controlled oscillator. The Fourier spectrum of this wave is a main frequency f.sub.c with two small sidebands at frequencies f.sub.c .+-.f.sub.s. This whole triplet is slowly swept in frequency by a slow sawtooth generator. The electrical signal is fed into a flat acoustic transducer; the acoustic wave is then transmitted through an acoustically active medium, i.e. the sample, and detected by another flat acoustic transducer which produces an FM signal with a superposed amplitude modulated (AM) signal if one of the sidebands overlaps an acoustic feature. This electrical signal is then demodulated to give a pure AM signal which can be phase sensitive detected by using a lock-in amplifier.

Abstract: A fiber optic writing head delivers light from the ends of a close-packed array of optical fibers through a small inexpensive lens which images the light onto the writing surface. The ends of the individual fibers in the array are fixed at various angular positions to form a surface that is the image of the writing surface through the lens. The ends of the fibers are spaced along the surface so that the image that is produced on the writing surface has uniform spacing. The angular positions of the fibers are chosen such that the axis of the refracted beam emitted by each fiber is directed at the center of the entrance pupil of the lens.

Abstract: A method of and structure for optical recording by energy-induced homogenization or fractionation is disclosed. When the method involves fractionation, a film is provided that contains a homogeneous mixture of a matrix material and an incident energy absorbing material. A spot on the film is treated with sufficient energy in the form of electric fields, radiation or heat, or combinations thereof to effect fractionation and/or homogenization of the film which will undergo further physical state transition only under treatment with additional energy. In a preferred embodiment, the fractionation is effected by laser radiation. The laser irradiated spot becomes inhomogeneous and can be detected by the resulting changes in its optical properties. When the method involves homogenization, a film is provided that contains a inhomogeneous mixture. The energy treated spot in this case becomes homogeneous without undergoing a phase transition between the amorphous and crystalline phases.

Abstract: A transistor array arrangement for providing high-density semiconductor logic circuits in double polysilicon technology is described. Semiconductor, for example, FET, logic circuits have four independent but simultaneously accessible FET devices which are formed by intersecting sets of polysilicon gate lines. The four FET devices share a common first diffusion, for example a source, surrounded by four logically independent second diffusions, for example drains. A three-bit decode device is made which includes this array design.

Abstract: This is a device that enables one to control the translation and rotation of an element relative to a light beam. The device has a rotatable member having a plurality of position-identifying circumferentially spaced openings therein as well as an aperture for the transmission of a light beam. The rotatable member is associated with translation means and rotating means. In a preferred embodiment the rotatable member is remotely controlled with a computer.

Abstract: A method for forming via holes having a rounded sidewall profile includes exposing a layer or organic positive photoresist to a formic gas plasma while the surface of the photoresist layer is bombarded with ions and electrons in a high voltage biased environment in which the photoresist layer is capacitively coupled. The photoresist layer may be exposed to UV light either before or after the formic gas plasma step.

Abstract: A color display is produced by overlaying two images from a single light valve. Filters are used to select the two primary colors used in the display. The two projection beams are folded and merged onto a dichroic mirror where they combine so that they follow an identical path to the screen. The dichroic mirror is positioned so that the two projection beams are equivalent when they strike the dichroic mirror. The dichroic mirror is an interference filter which reflects the spectral band passed by the first filter over a range of incident angles and transmits the spectral band passed by the second filter over the same range of angles.

Abstract: An apparatus forming a wedge shaped mirror tunnel makes the intensity distribution across a light beam uniform. A light beam is directed along a predetermined path through a cylindrical lens to focus the beam to a line at a particular point P. A plane mirror is placed along the predetermined path near point P so that the beam is folded onto itself. A plurality of cascaded optical means of this type, each stage of which comprises a focusing lens and a reflective surface, is used to achieve the beam uniformity needed for the chosen application. In each of the cascaded stages, the reflective surface is positioned at the appropriate angle to fold the beam upon itself.

Abstract: An opto-optical light deflector/modulator has means for providing first and second coherent wave fronts of wavelength (.lambda..sub.0) to travel in a transparent optical active medium to produce an optically generated standing wave that induces a periodic refractive index variation in the medium suitable for diffraction purposes. The device also includes means for providing a third wavefront (.lambda..sub.1) to travel in said medium which is diffracted by the periodic refractive index variation induced by the first and second wavefronts.

Abstract: A frequency multiplexed optical spatial filter is based upon a thin film of a photochemical hole burning material. The filter stores a plurality of images in the photochemical hole burning medium. The images are formed at different optical frequencies and coexist in the same volume of the storage medium. Individual images are accessed by changing the frequency of the illuminating radiation.

Abstract: A method and device for detecting dichroic and/or birefringent narrow spectral features in a sample is described. The method includes the steps of providing a beam of light having an optical frequency bandwidth which is narrow compared to the width of the narrow spectral feature and having a center frequency .omega..sub.

Abstract: A method of controlling the etch rate ratio of SiO.sub.2 /photoresist (PR) in a quartz planarization etch back process involves etching with a gaseous mixture containing CF.sub.4 and either CHF.sub.3 or C.sub.x F.sub.y with x>1 or O.sub.2. The preferred SiO.sub.2 /PR ratio of 1.2.+-.0.1 is obtained by either adding CHF.sub.3 to decrease the etch rate of the PR or by adding O.sub.2 to increase the etch rate of the PR.

Abstract: An electrochemical instrument for use with an electrochemical cell that provides IR compensation while operating as either a galvanostat or a potentiostat. The instrument includes an electronic circuit having two output terminals, an input differential amplifier circuit, an output differential amplifier circuit, a control differential amplifier circuit, a reference differential amplifier circuit, a resistor, electric circuitry connecting the input terminal of the control amplifier to the instrument output terminal and a double pole, double throw switch means. In a preferred embodiment, the electric circuitry connecting the control amplifier to the instrument output terminal is a potentiometer.

Abstract: An improved instrument for use with an electrochemical cell that provides a system having enhanced stability and increased bandwidth. The instrument includes a voltage to current converter which drives the cell. The current output of the voltage to current converter is linearly proportional to the differential voltage input. The voltage to current converter drives the cell in both the potentiostatic mode and in the galvanostatic mode of operation.

Abstract: A holographic optical head for imaging a laser diode for optical storage or magnetic tracking applications includes three holograms, a beam director and a quarter-wave plate. In a preferred embodiment the beam director is a fourth hologram. The holographic optical head is corrected for aberrations arising from its use with light sources other than the design wavelength by having the first hologram diffract the light into the -1 order direction. This light is then diffracted by the second hologram into the +1 order so as to eliminate aberrations normally caused by wavelength shifts of the laser source.

Abstract: An electron beam fabricated mask used in the production of integrated circuits is tested by a method that includes the steps of forming a print of the mask and then inspecting the print by writing the same electron beam pattern or complement thereof on the print and detecting pattern coincidence and non-coincidence with a vector scan system.