Accession Number : ADD016305

Title :   Time-Gated Imaging through Defense-Scattering Materials Using Stimulated Raman Amplification.

Descriptive Note : Patent, Filed 31 Mar 92, patented 4 Jan 94

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Reintjes, John F ; Duncan, Michael D ; Mahon, Rita ; Tankersley, Lawrence L ; Waynant, Ronald W

Report Date : 04 Jan 1994

Pagination or Media Count : 12

Abstract : An apparatus for the time-gated optical examination of objects that are part of, embedded in or viewed through dense scattering materials is disclosed. In a preferred embodiment, the apparatus comprises: a light source for producing a first light pulse and a pump light pulse, each of the first and pump light pulses having a preselected pulse width at a preselected pump wavelength; a Raman generator for shifting the wavelength of the first light pulse to a preselected Stokes wavelength to form Stokes light; a first optical train for transmitting the Stokes light through the dense scattering material to obtain Stokes light comprised of a relatively small, image-bearing signal component including unscattered Stokes light or Stokes light with minimal deviation due to scattering, light followed in time by a relatively large amount of light scattered by the dense scattering material; a Raman amplifier; an optical system for transporting the Stokes light from the dense scattering material to the Raman amplifier; a variable delay path disposed between the light source and the Raman amplifier for varying the transit time of the pump pulse to cause the pump pulse to overlap in time with the signal component of Stokes light at the Raman amplifier, the Raman amplifier only amplifying the signal component of Stokes light that is overlapped in time by the pump pulse; and a two-dimensional detector for detecting the amplified signal component of Stokes light.

Descriptors :   *MATERIALS, *SCATTERING, *TIME, *PATENTS, *GATES(CIRCUITS), *AMPLIFICATION, *IMAGE PROCESSING, AMPLIFIERS, BEARINGS, DELAY, DETECTORS, GENERATORS, IMAGES, LIGHT PULSES, LIGHT SOURCES, OVERLAP, PATHS, PULSES, PUMPS, SHIFTING, SIGNALS, TRANSMITTING, TWO DIMENSIONAL, VARIABLES, WIDTH, OPTICS, LASERS

Subject Categories : Electrical and Electronic Equipment
      Optics
      Laminates and Composite Materials

Distribution Statement : APPROVED FOR PUBLIC RELEASE