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Shulman, A. R.

Publications and source records attributed to Shulman, A. R..

17 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1980

Secondary electron emission from sodium chloride, glass and aluminum oxide at various temperature

The method of single impulses was used to measure the coefficients of the secondary electronic emission for 2 types of Al2O2, monocrystalline NaCl and glass at different temperatures and for different values of the energy of the primary electrons. The value of the secondary electron emission does not depend upon temperature. The effect of a gas film on the value of the secondary electron emission was detected.

Shulman, A. R.↗
NASA NTRS1977

Laser produces color images from digital data

Color recorder uses two lasers to generate three different-colored beams. Modulators vary intensity of each beam according to information stored on magnetic tape. Together, three beams are sufficient to reproduce virtually any colors on photographic film. Tape synchronizes motion of beam-writing carriage with modulation imposed on beams.

Shulman, A. R.↗
NASA NTRS1977

Method and apparatus for producing an image from a transparent object

The contrast produced from a photographic transparency is controlled by placing the transparency between a pair of partially reflecting mirrors forming walls of an optical cavity. Mirrors trap a collimated laser beam illuminating the transparency so that at least a portion of the beam energy is passed through the transparency plural times. The distance that the light beam travels between the mirrors is controlled as a function of the wavelength of the beam energy to control the phase of light interference in the beam passing through the transparency, thereby controlling the intensity of the beam derived from the mirror downstream of the transparency.

Lee, S. H.↗
NASA NTRS1976

Contrast enhancement of transparencies

System can enhance or reduce contrast of photographic transparency for printing or projection by using constructive and destructive interference of collimated laser beam. System is potentially less expensive than electronic CRT methods and is more accurate than trial-and-error manual techniques.

Shulman, A. R.↗
NASA NTRS1971

Noise diffraction patterns eliminated in coherent optical systems

Lens rotation technique of noise diffraction pattern elimination spreads diffracted energy, normally concentrated over small area of image, over much larger annular area. Technique advantages include simplified lens selecting process, reduced clean room requirements, and low cost equipment requirements.

Grebowsky, G. R.↗
NASA NTRS1971

Method and apparatus for eliminating coherent noise in a coherent energy imaging system without destroying spatial coherence

A method and apparatus for substantially eliminating noise in a coherent energy imaging system, and specifically in a light imaging system of the type having a coherent light source and at least one image lens disposed between an input signal plane and an output image plane are, discussed. The input signal plane is illuminated with the light source by rotating the lens about its optical axis. In this manner, the energy density of coherent noise diffraction patterns as produced by imperfections such as dust and/or bubbles on and/or in the lens is distributed over a ring-shaped area of the output image plane and reduced to a point wherein it can be ignored. The spatial filtering capability of the coherent imaging system is not affected by this noise elimination technique.

Shulman, A. R.↗
NASA NTRS1970

Optically activated magnetic recording tape

Optically activated data storage medium visually and electromagnetically reproduces a recorded signal. In an electric field, particles in heat-fluidized thermoplastic layer form a visible image of the recorded signal. Refluidizing the thermoplastic layer erases the signals. Very high data packing densities are achieved.

Marks, A. M.↗
NASA NTRS1970

Elimination of coherent noise in a coherent light imaging system

Optical imaging systems using coherent light introduce objectionable noise into the output image plane. Dust and bubbles on and in lenses cause most of the noise in the output image. This noise usually appears as bull's-eye diffraction patterns in the image. By rotating the lens about the optical axis these diffraction patterns can be essentially eliminated. The technique does not destroy the spatial coherence of the light and permits spatial filtering of the input plane.

Grebowsky, G. J.↗
NASA NTRS1970

Optical data processing

Book on optical data processing covering light characteristics, Fourier transforms, spectrum analysis, photographic film, filtering, holography, etc

Shulman, A. R.↗
NASA NTRS1968

Principles of optical-data processing techniques

Document presents optical-data processing information on a level which will convey the basic principles involved to those having a general technical background. Mathematical discussions are included but are not required for a basic understanding.

Shulman, A. R.↗