RESUMEN
Coherent Optical Adaptive Techniques (COAT) offer promise for overcoming the deleterious effects of phase distortions experienced by optical beams propagating in a turbulent and absorbing atmosphere. An 18-element, visible wavelength, multidither COAT system is described. The all solid-state servosystem design was based on the results of an extensive computer simulation. The optical system uses a 0.488-microm argon laser and an array of beam splitters, phase shifters, and beam combiners (termed a phasor matrix) to form the output array. To date, 6- and 8-element linear arrays and an 18-element axisymmetric array have been investigated. The system has demonstrated a convergence time of 1.2 msec and can form the array with a strehl ratio of 0.67. Moving glint tracking, multiple glint discrimination, and offset pointing from a fixed reference have been demonstrated. Good agreement has been observed between measured system results and theoretical predictions.
RESUMEN
The theory of multidither adaptive optical radar phased arrays is briefly reviewed as an introduction to the experimental results obtained with seven-element linear and three-element triangular array systems operating at 0.6328 microm. Atmospheric turbulence compensation and adaptive tracking capabilities are demonstrated.