Showing papers on "Collimated light published in 1970"

Some Applications and Properties of One- and Two-Dimensional Position-Sensitive Proportional Counters

Abstract: A new method was developed for determining the position of ionizing events by measuring the risetime of output pulses from detectors having high resistance collectors. Basically, these detectors are distributed RC lines; information about the location of an ionizing event is obtained from the analysis of the frequency spectrum of the detector output pulse, and the energy loss of this event in the detector is measured by analyzing the amplitude of the same output pulse. Three typical prototype detectors were constructed and tested in a series of imaging and diffraction experiments using ionizing radiation. The spatial uncertainty for collimated 210Po alpha particles was 0.15 mm fwhm for a 200-mm-long proportional detector. The spatial uncertainty for collimated 20-kev x rays was 0.5 mm fwhm for a 400-mm-long detector. A two-dimensional system using parallel wires was developed and evaluated. With only four preamplifiers and relatively simple shaping and timing circuitry, 24,000 resolution elements (measured at fwhm) were obtained with a 30-wire counter having a sensitive area of 75 × 120 mm2. These position-sensitive detectors are well suited for application in the life sciences for the localization of radioactive tracers in medical studies or in the structure determination of large organic molecules, with x-ray or neutron diffraction; in fluorescent x-ray or neutron spectroscopy; small-angle scattering experiments with x rays or neutrons.; magnetic spectroscopy of protons and other charged particles; two-dimensional chromatography; x-ray astronomy; and fission physics experiments.

Interferometric measurement of angles.

Abstract: A new interferometric device for measuring small angles or rotations with high accuracy is described. This instrument works by counting fringes formed by the rotation of a flat-parallel plate of glass illuminated with a collimated beam from a gas laser. Some possible applications are given.

Method of and apparatus for the separation of isotopes

Abstract: A method of and apparatus for the separation of an isotope from a working medium wherein a beam of atoms comprising the working medium may be generated in an oven and collimated with a suitable collimator. The collimated beam of atoms is directed through an evacuated region where two photon beams are applied to the beam and function respectively to excite and ionize a selected isotopic constituent of the atomic beam. The ionized isotope may then be removed from the atomic beam by electric or magnetic fields and collected on a collecting plate.

Controlled optical beam forming device

Abstract: A controlled optical beam forming device distributes the light from a collimated source such as a laser within a controlled solid pattern with any desired relative intensity distribution. The device is formed of two optical elements. The first element apportions the beam into a plurality of extensive zones. The second element diffuses the light in the zones to form a beam having the desired form and distribution.

Optical display systems

Abstract: Collimated light carrying visual information is projected via a partial reflector on to a reflex-reflector which returns the light to the partial reflector for viewing by an observer who sees an image of the visual information at infinity. A flight simulator and a head-up display apparatus employing this system are described.

Correction of astigmatism in a Czerny-Turner spectrograph using a plane grating in divergent illumination

Abstract: A method for eliminating the astigmatism of a Czerny-Turner spectrograph is described in which the grating is used in divergent illumination. Expressions are given for the distances of the tangential and sagittal astigmatic images from the camera mirror in terms of the separation between the entrance slit and the collimating mirror and the condition for the elimination of astigmatism is derived. These results are compared with ray tracing data for a practical instrument. Experimental tests of spatial and spectral resolution for an f/15 spectrograph of 06 m focal length are given at wavelengths 5461 and 2800 A. Over a spectral range of 100 A centred on 2800 A a spatial resolution along the slit in excess of 50 cycles mm−1 has been achieved for a flat inclined image plane. For the same spectrograph with the grating in collimated light the spatial resolution is only 3 cycles mm−1.

Turbidimeter utilizing back scatter

Abstract: A turbidimeter having a probe mounted in a single opening in a fluid flow line which has a smooth uniform face in contact with the flowing fluid, a collimated incident light source and a photosensitive cell positioned to receive back scatter light

Acousto-optical signal processing system

Abstract: An acousto-optical signal processing system usable for signal correlation or spectrum analysis. Collimated light passes through an acousto-optical cell to provide a spatial carrier that is modulated in accordance with signal information. A time integrating imaging detector, such as a Vidicon, receives this carrier, and a filter separates the modulating signal information from other light signals received by the imaging detector. Resolution requirements of the imaging detector are reduced by an optical grating. The acousto-optical cell may have reflectors causing the incoming light to make several passes across the cell before exiting.

Display system utilizing a selectively deformable light-reflecting element

Abstract: A LARGE SCALE DISPLAY SYSTEM UTILIZING A DEFORMABLE METAL FILM LIGHT-REFLECTING SURFACE OR LIGHT VALVE IS DISCLOSED. A LIGHT VALVE IS ASSEMBLED CONSISTING OF A VERY THIN METAL FILM MOUNTED ON A SUPPORT GRID. AN AREA OF DIELECTRIC MATERIAL IS PLACED ON THE LOWER SURFACE OF THE FILM WITHIN EACH GRID OPENING. THIS ASSEMBLY IS PLACED IN A CATHODE RAY TUBE SO THAT AN ELECTRON BEAM MAY BE CAUSED TO IMPINGE UPON THE DIELECTRIC AREAS. IN ONE EMBODIMENT, A CONVENTIONAL OPTICAL SYSTEM IS USED TO DIRECT COLLIMATED LIGHT AGAINST THE UPPER SURFACE OF THE METAL FILM. LIGHT REFLECTED FROM DISTORTED PORTIONS OF THE METAL FILM IS TRANSMITTED TO A DISPLAY SCREEN, WHILE LIGHT REFLECTED FROM UNDISTORTED PORTIONS OF THE METAL FILM DOES NOT REACH THE SCREEN. WHEN THE ELECTRON BEAM IMPINGES UPON THE DIELECTRIC AREAS, THE AREAS ARE ATTRACTED BY ELECTROSTATC ATTRACTION FORCES TOWARD THE ADJACENT GRID MEMBERS. THIS CAUSES SUFACE DISTORTIONS OR DMPLES IN THE METAL FILM. A SPOT OF LIGHT APPEARS ON THE DISPLAY SCREEN AT LOCATIONS CORRESPONDING TO THE DIMPLE LOCATIONS. WHERE THE DIELECTRIC AREAS ARE VERY SMALL AND CLOSELY SPACED, AN IMAGE CORRESPONDING TO THE AREAS SCANNED BY THE ELECTRON BEAM WILL APPEAR TO THE DISPLAY SCREEN.

X-ray collimator having a fiber optic light source therein for alignment purposes

Abstract: X-ray collimator having a fiber optic light source attached thereto, and method for accurately aiming a collimated X-ray beam at a test sample using fiber optic light source.

Optical character spacing system for phototypesetting

Abstract: A character image projection system successively projects image bearing light beams along a common optical axis toward a photosensitive surface. The images of the individual characters are spaced on the photosensitive surface to form lines of composition. The spacing is accomplished by collimating the image bearing light beams, then diverting the collimated beam by means of a movable reflecting surface into a refocusing and scan lens assembly from which the light beams emit onto the photosensitive surface. The position of the reflector may be controlled by a servo mechanism which responds to character image space information from a computer. The refocusing and scan lens assembly incorporates compensation for the angular position of the reflecting member whereby the character images remain in focus and are properly spaced even though the photosensitive surface is maintained flat at the image plane of the system.

Holographically produced image arrays for photolithography

Abstract: This disclosure describes the generation of multiple identical images holographically. Wavefronts from a unit pattern and a pinhole array separately illuminated by branched, spatially filtered and collimated laser beams are Fourier-transformed and focused in front of a holographic medium. Illumination of the developed hologram with a laser beam conjugate to the wavefront from one of the pinholes produces a spaced array of real images of the unit pattern. The process is useful in photomask making, or as a way to directly expose photoresist in silicon device manufacture.

Image spacing system

Abstract: An image projection system successively projects images along a common optical axis toward a photosensitive surface The individual images are spaced side by side on the photosensitive surface The spacing is accomplished by collimating the image bearing light beams, then diverting the collimated beam by means of a movable reflecting surface (or equivalent) into a refocusing and scan lens assembly from which the light beams emit onto the photosensitive surface The position of the reflector is controlled by any suitable means such as a servo mechanism The refocusing and scan lens assembly incorporates compensation for the angular position of the reflecting member with respect to the optical centerline, whereby the images remain in focus and are not distorted even though the photosensitive surface is maintained flat at the image plane of the system

Color correction of prismatic off-axis optical system

Abstract: Unmodulated, collimated white light is angularly directed to a target reflecting surface which is deformable to represent a subject, and the subject-modulated light reflected from the target surface is directed to a viewing screen by a Schlieren optical system including a projection lens and a stop at the focal point of the lens. A first prism is located between the subject-bearing target surface and the lens to render the light reflected from the target surface orthogonal to the principal plane of the lens and the screen. A second prism is located between the lens and its focal point to effect a color correction of the subject-modulated light reflected from the target surface.

Fiber Optics. XII. A Technique for Launching an Arbitrary Mode on an Optical Dielectric Waveguide

Abstract: A spatial-filtering technique is described which provides a means for launching an arbitrary mode on a fiber-optical waveguide. Appropriate amplitude and phase filters are used to discriminate against unwanted modes. These are inserted in the pupil of a launching lens which focuses collimated light onto the end of the guide. A double-path illuminating system is generally needed to obtain the required input polarization. The method is evaluated both theoretically and experimentally, and the agreement is found to be good within the practical limitations of cross-sectional irregularities in the nominally circular optical fibers.

Interferometric apparatus with controlled scanning means

Abstract: Apparatus is herein disclosed for exposing a recording plane to an interferometric exposure pattern composed of a set of light interference fringes. A beam of highly coherent collimated light is split into at least two beams and the split beams recombined in a recording plane to create an interference pattern of light and dark fringes. At least one flat glass plate is repositionable in the unsplit light beam and serves to shift the position of the light beam whereby the beam of light leaving the plate is substantially parallel to the light beam entering the plate. This, in turn, causes the illuminated portion of the recording plane to be shifted to a new location without altering the phase relationship between the various beams at any point in the recording plane. Each bright fringe therefore remains in a stationary position and only changes in intensity as the exposure pattern is scanned in the recording plane. The movement of the plate is programmed so that the illumination is scanned in the recording plane to produce a uniform exposure of the interference fringe pattern.

Optical system calibration method

Abstract: A method for the calibration of distortion in optical systems. A beam of collimated light is diffracted into various orders by being passed through a diffraction grating. The diffracted light emerging from the grating is then refocused by the optical system being calibrated resulting in an array of images in the focal plane of the optical system. The relationship between the actual positions of the images in the array and the calculated positions for a distortion-free system provides a measure of the distortion present in the system.

A method for mapping the spatial distribution of stopping π - mesons in tissue

Abstract: A method is discussed for locating the stopping position of pi - mesons in tissue. The gamma -rays emitted following the capture process are collimated and converted to electrons. They are detected with a plastic scintillator and their position is determined with a magnetostrictive wire spark chamber. The sensitivity and resolution of the system are measured.

Scanning mirror alignment techniques

Abstract: In a multifaceted mirror scanner, a mirror attached to a carrier that is precisely positioned receives energy from a collimated beam of light and reflects this energy toward a predetermined target point. The carrier is then deformed, such as by making a dimple near an edge where the mirror should be raised slightly, to deflect the beam so that the reflected image is precisely oriented on the target point.

Remotely sensing optical tachometer

Abstract: A remotely sensing optical tachometer for measuring the spin rate of a rotating member. The invention provides a simple optical system for measuring the spin and/or rate of change of spin, of, for example, an artillery shell or test projectile. The system provides a real-time readout of the spin rate, and requires no instrumentation aboard the projectile except for a small plane mirror that is attached obliquely to one end of the spinning projectile. The system directs a collimated beam of light that is reflected off the plane mirror back into the system where it traverses a stationary reticle that has alternating transparent and opaque sectors thereon. The frequency with which the light passes through the transparent portions of the reticle provides a direct indication of the spin rate of the rotating member. The signal may be detected by a photo tube, amplified, and displayed on an oscilloscope, or recorded on magnetic tape, or be processed through a frequency-to-DC converter.

Automatic transform analyzer

Abstract: An optical data processing system of the coherent spatial filter type which (a) produces enhancement of the contrast of filtered images before they are photographed by providing a controllable optical attenuator in the path of the filtered light, the amount of light permitted to shine through the attenuator being a function of the intensity of the light, and (b) produces a rose diagram by providing a rotatable slit of adjustable length that is rotated in synchronism with the spatial filter, the length of the split being varied in accordance with the intensity of the light passing through the spatial filter; a camera is provided to record light from a conventional source that is collimated and passed through the rotatable slit.

Hologram graphic data tablet

Abstract: A holographic tablet device comprises a recording plate on which an array of holograms is arranged. Each hologram has coded positional information therein corresponding to its location on the plate. The recording plate is illuminated with a collimated monochromatic or substantially monochromatic beam by an indicating device. Diffracted beams are thereby produced corresponding to which of the holograms have been illuminated. The diffracted beams are detected and corresponding binary signals are produced. Also disclosed is an arrangement for maintaining a desired constant angle between the illuminating device and the recording plate.

Automatic rangefinder electronic circuitry

Abstract: This invention relates to automatic range finder circuitry for cooperative utilization with apparatus, such as a photographic camera or the like, using triangulation for range distance measurement, and having an automatic range finder mechanism. The apparatus is arranged to sweep a collimated light beam across a plane which includes a subject of interest, and the reflected light returning to the apparatus is imaged on spaced photoelectric transducers differentially connected to produce a varying electrical signal. The range finder mechanism includes a cam adapted to move as a function of the sweeping light beam. When the reflected light falls equally on the photoelectric transducers the range distance has been established. The present invention supports this apparatus by providing circuitry for detecting the instant that the reflected illumination on the photoelectric transducers is equal, and for providing an output signal which is used to lock the cam against further displacement. The range distance intelligence, defined by the locked cam position, can then be utilized for any convenient purpose.

Apparatus for producing an interference pattern

Abstract: A beam splitter and a mirror form from a laser beam a pair of converging collimated beams directed to the primary focal point of a spreading lens. The lens combines and spreads the beams so that they overlap to produce an interference zone. A device is provided for adjustably moving the above-mentioned optical elements to vary the fringe spacing of the interference pattern.

Information storage systems utilizing amorphous thin films

Abstract: The system disclosed herein employs an amorphous semiconductor thin film which is switched between two stable states by applying a focused beam of laser energy. In one state the thin film exhibits specular reflection while in the other state it exhibits diffuse reflection. Data bits or images are recorded by the laser beam on the thin film. This information is retrieved by illuminating the thin film with collimated light, by employing the same laser beam used to record the information, or by recording on a sensitized medium.

Optical image processor

Abstract: A processing array which permits the simultaneous filtering of a single input image by a number of different spatial frequency filters. A coherent collimated beam of light is divided into a plurality of smaller beams. The smaller beams are then collimated and are directed through a single portion of an input transparency. The beams coming from the input transparency are then directed through a transforming lens which produces the Fourier transform of each of the beams in the focal plane of the transforming lens. Because the Fourier transform of each beam is located at a different position in the Fourier plane, a different filtering operation can be performed at each of the points in the Fourier plane.

A Thermal Energy Molecular Beam Source for Use in Scattering Experiments

Abstract: A new nozzle source is discussed that produces a high-intensity molecular beam with very small dispersion in velocity When signal-to-noise ratio in scattered beam experiments is used as a measure of performance this source is shown to be approximately equal in quality to a Kantrowitz-Grey source of comparable size Furthermore it is argued that many existing Kantrowitz-Grey sources could be operated as simple nozzle sources with no appreciable loss in performance The present source has several new features The beam intensity is uniform over the beam cross section Source performance is not strongly dependent on skimmer geometry; hence, a simple collimating hole in a plate suffices Source performance is quite insensitive to the size of the collimating hole and its distance from the nozzle; thus, they may be adjusted to tailor the size and shape of the beam to the particular application The present source may be uniquely suitable for a proposed new method of beam collimation

Absorption and scattering of thermal radiation by a cloud of small particles

Abstract: An experimental investigation was made of the absorption and scattering of thermal radiation by a cloud of small, spherical, micronsized, aluminum oxide particles in a plane-parallel enclosure. By using carbon tetrachloride and carbon disulphide as suspendign media, transmission measurements were made with collimated and diffuse sources for wavelengths from 2 to 11μ. By employing a two-flux diffuse model, the data were correlated to obtain absorption and back-scattering cross sections. From the diffuse and collimated data, a backscattering coefficient was found which varied linearly with relative refractive index. With the developed coefficients, the absorptivities of the cloud of particles were determined.