Accession Number : ADD012699

Title :   Discrete Phase Conjugate Technique for Precompensation of Laser Beams Transmitted through Turbulence.

Descriptive Note : Patent,

Corporate Author : DEPARTMENT OF THE AIR FORCE WASHINGTON DC

Personal Author(s) : MacGovern,Alan J

Report Date : 06 Jan 1987

Pagination or Media Count : 9

Abstract : A process and apparatus are disclosed for aligning a laser beam from a laser transmitter with an incoming laser beam, and driving any sensed tilt differences on an aperture and subaperture basis to zero. The apparatus uses a shared apperture component to sample the outgoing laser beam and the incoming target beam, retroreflector array to reverse the direction of the subaperture samples of the outgoing beam, a common-mode wavefront sensor to measure subaperture tilt differences between the reversed samples of the laser and the incoming target beam, and a deformable mirror to drive any sensed tilt differences to zero. A transparent beamsplitters used as the shared aperture component and an AC shearing interferometer is used as the basis for the common-mode sensing. By forcing the outgoing beam to be then conjugate of the incoming beam it is automatically precompensated for any aberrations in the transmission path. (Patents)

Descriptors :   *PATENTS, *TURBULENCE, *LASER BEAMS, *COMPENSATION, *CONTROL SYSTEMS, DEFORMATION, DRIVES, MIRRORS, LASERS, TRANSMITTERS, REVERSIBLE, SAMPLING, PATHS, TRANSMITTANCE, ARRAYS, RETROREFLECTORS, REVERSIBLE

Subject Categories : Lasers and Masers
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE