CORRECTION OF SEGMENTED MIRROR ABERRATIONS BY PHASE-CONJUGATION AND DYNAMIC HOLOGRAPHY

A novel approach is proposed for using the phase conjugation phenomeno n for dynamic correction of distortions in beam forming laser systems. The method is based on the well-known application of a special diffra ction structure on the surface of corrected optical elements ensuring nonreciprocal beam propagation in a system including a phase conjugate mirror. The main feature of the proposed approach is that it uses the diffraction structure which is not static (as usually) but is written dynamically by a small auxiliary laser source irradiating the correct ed element surface simultaneously with the working beam. This makes it possible to extend the capabilities of the known method with respect to scaling-up the size of compensated mirrors and allows replacement o f a large solid mirror by a segmented one. The novel method of correct ion has been tested experimentally by the use of 1.06 mu m radiation f or recording the dynamic hologram and a 10.6 mu m laser beam as the wo rking beam, distorted by a two-segment mirror with a dynamic hologram on its surface and corrected by a phase conjugate mirror. The means of dynamic hologram recording in different spectral ranges are discussed .