Accession Number : ADD017617

Title :   Time Gated Imaging Through Scattering Material Using Polarization and Stimulated Raman Amplification.

Descriptive Note : Patent, Filed 15 Jan 93, patented 23 May 95,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Bashkansky, Mark ; Reintjes, John F

Report Date : 23 May 1995

Pagination or Media Count : 14

Abstract : An apparatus for imaging through scattering materials produces a broadband laser reference beam and a correlated Stokes illumination beam. The broadband reference beam has a preselected Raman pump wavelength and the Stokes illumination beam has a preselected Stokes wavelength. The Stokes illumination beam is transmitted into the scattering material to obtain a Stokes signal beam having a first image carrying component and a first nonimage component. A relative delay is produced between the reference beam and the Stokes signal beam. The delayed reference beam and the delayed Stokes signal beam are polarized. The polarized reference beam and the polarized Stokes signal beam are combined to produce a combined beam having a Stokes component and a reference component, the Stokes component having a second image carrying component and a second nonimage component, so that the second image carrying component and the reference component are mutually correlated, and so that the polarization state of the Stokes component differs from the polarization state of the reference component. A Stimulated Raman amplifier responsive to the combined beam produces an amplified signal beam having a third image carrying component with polarization state perpendicular to the polarization state of the Stokes component and having a third nonimage component with polarization state parallel to the polarization state of the Stokes component. The third image carrying component is separated from the rest of the amplified signal beam with the use of a polarizer and is later detected. (MM)

Descriptors :   *LIGHT SCATTERING, *GATES(CIRCUITS), *OPTICAL IMAGES, *RAMAN SPECTRA, *PATENTS, POLARIZATION, ILLUMINATION, LASER BEAMS, HOLOGRAPHY, BROADBAND, OPTICAL SWITCHING, LASER AMPLIFIERS

Subject Categories : Electrooptical and Optoelectronic Devices
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE