RESUMO
A holographic technique to compensate for atmospherically induced phase distortion of a 10.6-micro laser beam is presented. After a brief outline of the principle of adaptive phase-distortion compensation, the experimental setup to demonstrate feasibility is described. Results obtained for a reflecting target at distances of 150 m and 4600 m are presented and discussed in detail. It is shown that the power delivered onto a target and thus the return signal can be significantly increased by the principle of adaptive phase-distortion compensation. By compensating for phase distortions in both the transmitted and received beams, the signal-to-noise ratio of the received signal can be improved by a factor of N(2), N being the number of apertures used, if the phase relation was completely random beforehand. The results of these tests demonstrate that large arrays can be utilized in spite of the distorting effects which are normally produced by the atmosphere.
