COHERENT OPTICAL ARRAY TECHNIQUES.
Abstract
Studies were conducted to determine the feasibility of a coherent optical phased array system. A fully developed transmitter will provide a greater concentration of beam power on distant targets and electronic beam steering. Feasibility was demonstrated by driving two pulsed neodymium glass laser power amplifiers in a Mach-Zehnder configuration with a laser master oscillator. A servo controlled phase shifter in the path of one laser amplifier permitted in-phase recombination of the two amplifier outputs to produce more output than possible with a single amplifier. The phase stabilization provided by the servo functioned only in the period between pump pulses but proved adequate for continued phase alignment throughout the pump period. Measurements of far field patterns of separated output beams from two amplifiers driven by a pulsed master oscillator showed the expected major and minor lobes. At high average pump powers, changes in radiation pattern caused by thermal distortion effects in the laser glass were observed. Such effects were analyzed and determined to be correctable in a fully developed system. Correction for strain birefringence was demonstrated successfully in an experiment using uniaxial crystal plates to simulate thermally induced birefringence.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1966
- Accession Number
- AD0802670
Entities
Organizations
- Sperry Corporation