Abstract: An optical beam steering device for use in a single-aperture laser transceiver system provides deflection of the transmitted and received beam in two planes, while maintaining the distinctive identities, of each channel respective to their polarizations. The invention utilizes four single-dimensional beam deflecting devices, two for each orthogonal linear polarization of the two transceiver channels, one of these for each steering axis. In addition, a 90.degree. polarization rotator and a quarter-wave plate are included in the arrangement of beam deflecting devices to satisfy the polarization requirements of these devices and of the transceiver channels.

Abstract: An interferometer wherein detected local oscillator beam power is variable without varying detected target-reflected return beam power. A P-polarized beam of energy is produced along a predetermined path. First and second waveplates are serially disposed in the predetermined path. Also included are a beamsplitter disposed in the path between the first and second waveplates, and a polarization analyzer disposed in the path between the beam producing means and the first waveplate. A first portion of the P-polarized beam couples through the first waveplate, the beamsplitter and the second waveplate, and is transmitted to a target, the first and second waveplates altering the polarization of the transmitted beam to circular polarization.