DESIGN AND DEVELOPMENT OF A CLOSED LOOP ADAPTIVE OPTICS SYSTEM FOR WAVEFRONT SENSING AND CONTROL

Atmospheric distortion limits the quality of images obtained witll ground-based telescopes. Similarly. laser beam propagation through turbulent, almosphere results ill discontinuity in satellite optical links. Adaptive Optic techniques provide compensatioll for the aberrations introduced due to the random refractive index fluctuations of the atmosphere. In this paper, we present the practical details of the successful design and development of a low-cost Shack-Harimam wavefront analyzer. as well as a closed loop Adaptive Optics system which compensates the global till and the local phaseflllctuations of a wavefrom. The Shack hartmann sensor measures the wavefront profile ill real time and generates correction signals. Global lill measurements to accuracy of 19 mu radians and phase profiles up to lambda/50 have been acheived. Dynamic corrections have been made with tip-tilt mirror and a deformable mirror. The Opto-mechanical system. software design, and implementation are described. results of wavefrom measurements ancl correction of aberrations are presented.