Abstract: In measuring the width of rolled stock, a photo-sensitive diode array overlying an edge of the stock is scanned to provide an indication of the position of the edge of the stock, the outputs of the diodes appearing serially to provide a waveform. To find the step in this waveform which represents the edge, the waveform is filtered to replace falling edges by shallow slopes and rising edges are detected in a peak rectifier/capacitor arrangement which can only discharge slowly. An output comparator is triggered in each cycle (except the first) by any rising edge signal which causes charging of the peak storage capacitor. The output comparator signal indicates the position in the scanning cycle of the article edge.

Abstract: A device for measuring and recording spontaneous blood platelet aggregation in platelet-rich citrated blood plasma comprising a photometer having a source of light, a photo cell, a light filter and a rotating disk cuvette for receiving the platelet-rich citrated plasma to be tested.

Abstract: A detection system for automatically detecting a first light transmissive substance in a second and different light transmissive substance. An optical system is arranged for alternately producing light beam flashes of light having a first wavelength and light having a second wavelength to the input of an opto-electric detector. A volume containing the first and the second substance can be selectively positioned at the output side of said optical means in front of the opto-electric detector. The opto-electric detector delivers its electrical signals corresponding to the light beam flashes received thereby, to a electrical detecting arrangement. The electrical detecting arrangement comprises first means for producing a first voltage proportional to the ratio between light transmitted through the volume under inspection at the first wavelength and light transmitted through the volume under inspection at the second wavelength, and second means for producing a second voltage indicative of a threshold level.

Abstract: A beam of light angularly directed relative to a surface of an object having a dimension to be measured is intercepted by the object, which is moving at a known speed. By knowing the beam angle, the object speed, and the time lapse between the passage of the object past a reference point and the point of beam interception, the dimension of the object is readily determined.

Abstract: Described is a technique for generating directly certain derivatives of device parameters by measuring the device response to ac modulation under conditions of constant modulation index. In particular, the technique as it applies to measuring directly idF/di and i.sup.2 d.sup.2 F/di.sup.2 for AlGaAs DH p-n junction lasers is described for two cases: where the generalized function F equals either voltage V across the laser or the light intensity output L of the laser, and i equals current through the laser. For p-n junction lasers this technique permits measurement of the series resistance R.sub.s, lasing current threshold i.sub.th and the exponential factor .beta. = q/nkT.

Abstract: Methods and apparatus for directing radiation pulses to a region wherein either a pulse or a substance in the region is adversely affected by the presence of more than a given power density therein. A laser pulse is split into a plurality of portions and each portion is directed along a path of different length to provide in rapid succession a plurality of pulses each having less than the given power density. Each pulse is caused to arrive at the region at an angle differing by at least its divergence angle from the arrival angle of every other pulse (or, if at a smaller angle from another pulse, with opposite polarization therefrom) and at a time enough later than the arrival time of the preceding pulse that the total power density in the region at any instant is less than the given power density. Thus, the effective total power density of the radiation directed through the region may exceed the given power density without adversely affecting any pulse or substance in the region.

Abstract: A method and apparatus for measuring deflection of rotating members, such as the blades of a turbomachinery stage, are provided. The rotating member is illuminated with a high intensity light beam, such as a laser, at least one location upon the member where deflection is to be determined. Another location which serves as a reference is also illuminated in a similar manner. As the rotating member passes through the light beams, the light beams are reflected from reflective patches, thereby producing light impulses which are received by a light measuring device. The light pulses are converted to electrical impulses, the time increment between pulses being a function of the distance between the two locations and, thus, a measure of deflection. The dynamic component of blade-to-blade vibration is determined by comparing the time increments for a plurality of blades in the stage.

Abstract: A method and apparatus for determining the temperature of gaseous materials are provided. Light produced by scattering in a gaseous material and having spectral components periodic in frequency is collected, collimated and transmitted by a light conditioning means to an interferometric means. The interferometric means selectively separates periodic spectra from the light and transmits the spectra in the form of a detectable signal containing first and second branches of the spectra. Means are provided for measuring the intensities of the branches and detecting and recovering the intensity ratio thereof, which is correlated with the temperature of the gaseous material.

Abstract: A method and apparatus for measuring the height of a blade of a turbine rotor as the rotor is being rotated characterized by deflecting a laser beam at a given deflection frequency across the path of the moving blade so that a portion of the deflected beam will be reflected by the end of the blade, sensing the reflected portion to produce a reflected signal, synchronizing the speed of rotation of the rotor with the frequency of deflection so that the end of the blade and the deflected beam reach the same point simultaneously and applying the reflected laser signal and a reference signal from the laser beam to an electronic analysis system to determine the height of the individual blade. Preferably, the synchronizing is accomplished by sensing the blade frequency, converting it to a converted blade frequency, comparing the converted blade frequency with the frequency of deflection to obtain an error signal and using the error signal to control the speed of rotation of the rotor.

Abstract: An electronically tunable optical filter is described wherein an optical beam is diffracted by an acoustic beam the group velocity of which is noncollinear with the optical beam transmitted through the birefringent crystal medium. The frequency and the direction of the phase velocity of the acoustic wave are chosen for a given incidence direction of the optical beam so that the diffraction occurs for a band of optical frequencies centered about a predetermined optical frequency and a relatively large angular distribution of incident optical beams.

Abstract: An optical means for detecting and/or communicating with underwater objects rom airborne platforms wherein a number of laser sources are collimated so as to illuminate a particular portion of the ocean surface from the airborne platform. Thereafter, use is made of the non-linear optical phenomena resulting from the interaction of the various source characteristics (power and wavelength) with the water media to detect modulation of the specularly reflected energy to provide indications of the presence of submerged objects.

Abstract: Very rapid and accurate linewidth measurements in selected subregions of an LSI mask or wafer are made by means of a low-cost apparatus. The apparatus embodies the recognition that an accurate linewidth determination can be made for any particular feature among a variety of features in a repeated array by a calibrated and normalized measurement of the average light transmission or reflection of a subregion that includes the feature. In turn, the measurement is automatically converted to a linewidth reading by analog computing circuitry.

Abstract: A method of making a light polarizing material having excellent polarization characteristics over wavelengths from the visible to the infrared (IR) region is disclosed. A smooth surface of an optical material, such as for example glass, plastic or IR transmitting material, is mounted in a vacuum enclosure and a vaporized material or metal is directed onto the surface. The metal may be gold, silver, copper or aluminum, for example, or any other material or combination thereof which is reflective at the wavelength to be polarized. As the deposition occurs on the surface, metal atoms are initially attached to sites on the surface with metal whiskers forming on the initial sites in the direction of the incident vaporized metal. The metal whiskers are grown with their long axis essentially parallel to the vaporized metal direction and essentially parallel to each other.

Abstract: Improved contact means for use in a weather resistance and solar radiation tester having a specimen rotating frame having leads extending through the shaft and a meter for indicating the amount of light received by the light receiving element. The improved contact means is for electrically connecting the leads to the meter, and has a rotating shaft connected to the shaft for the specimen rotating frame, upper and lower cases surrounding the rotating shaft and in which the rotating shaft is rotatably journaled and defining two separate compartments spaced along the rotating shaft and sealed from each other, the cases being of electrically insulating material. A metal ring is fixed in the bottom of each case and a lead extends from each ring out through the respective case for connection to the meter. A plate spring in each compartment is fixed to the rotating shaft, and contact pieces on the ends of the plate spring in each compartment are held in sliding contact with the metal ring therein.

Abstract: An improved holographic instrument for evaluating the structural integrity of a load-bearing structure by recording on a holographic recording medium two successive holograms of the structure under differing stress conditions to produce a holographic interferogram containing information defining a deformation fringe pattern representing the deformations in the structure resulting from the change in stress conditions. A holographic recording unit for the optical signature instrument and for general holographic recording use.

Abstract: The microfiche card has micro images arranged in horizontal rows and vertical columns. The card is inserted into the slots at the fronts of the sides of the housing and can be moved to align the desired column with the lens. The lens is vertically movable on the front of the housing and can be aligned with the desired row of images. The back of the housing has a light gathering lenticular panel which transmits light into the light chamber where it is diffused and illuminates the light diffusing (Opal) glass and the micro image. Under low ambient light conditions the switch on the handle may be depressed to illuminate the bulb in the light chamber. The handle houses the batteries which power the bulb. The focal length of the ocular is selected to provide the proper magnification of the image to make the image readable.

Abstract: There is disclosed a gas discharge device containing electrode arrays, an ionizable gaseous medium, and a phosphor excited at least in part by radiation from the gas discharge of the device, the life of the phosphor being increased by the application of a phosphor overcoat which is at least partially transmissive to excitation radiation from the gas discharge. The phosphor overcoat is typically selected from alkali and alkaline earth fluorides. In one embodiment, the gaseous medium comprises at least one rare gas selected from neon or argon and at least one other rare gas selected from argon, xenon, krypton. The gas discharge device is preferably of the display/memory type wherein electrical charges are stored on opposing dielectric surfaces, the phosphor and phosphor overcoat being positioned on the dielectric surfaces near the gas discharge.

Abstract: An element in which only a single domain-wall can move sidewise, having a crystal plate of an irregular ferroelectric which is cut in the Z-plane at opposite surfaces and is then cut or cleaved in the <110> direction at its periphery and transparent electrodes for the polarization reversal provided at the central portions of the opposite Z-planes. The element includes at least a domain configuration such that two nucleus regions of opposite polarities are disposed on opposite sides of the region, i.e., a domain having a stationary polarity, where the electrodes are provided.

Abstract: A method and apparatus for the determination of blood cell osmotic fragility, wherein a solution of salt, such as sodium chloride, with an osmotic gradient decreasing with time is passed through a coiled capillary tube, positioned with its axis vertical so that the flow through the turns of the tube is substantially horizontal, and the flow follows Poiseuille's parabolic flow pattern. The blood sample is inserted in the coiled tube and, because of the flow pattern, the salt solution travels through the capillary tube much faster than the erythrocytes, so that the erythrocytes are exposed to gradually decreasing osmolarity for hemolysis. Optical monitoring is carried out as the hemoglobin is rapidly removed from the flowing stream. Optical density is recorded against time, employing a 547 nm monitoring beam, thus providing a hemolysis curve.

Abstract: An optical polarization rotator is implemented without any magnetic field by using dispersion due to two-photon transitions. The polarization rotator is useful for powerful coherent linearly-polarized optical beams. A second powerful circularly-polarized coherent optical beam provides control for the polarization rotation of the linearly-polarized beam which interacts more strongly with the oppositely circularly-polarized component of the first beam than with the other component of the first beam. The difference in interaction occurs because the gaseous medium atoms in the cell in which the interaction occurs begin and end a nearby resonance transition that determines the two-photon dispersion in the same angular momentum state; and, because of this quantum state selection rule, the result is a relative delay between the two circularly-polarized components of the linearly-polarized beam and a consequent rotation of the orientation of linear polarization.