Adaptive wave-front correction by means of all-optical feedback interferometry

A novel adaptive wave-front correction system based on an all-optical feedb ack interferometer is described. In this system the two-dimensional output fringe intensity from a Mach-Zehnder interferometer with large radial shear is optically fed back to an optically addressed phase-only liquid-crystal spatial light modulator. Consequently, without a separate aberration-free r eference wave, the modulator phase approximates the conjugate of the interf erometer phase that is directly related to the phase of the input aberrated wave front, so this system is applicable in adaptive optics. We successful ly achieved real-time correction of aberrated wave fronts: A diffraction pa ttern that was seriously distorted because of aberrations was transformed i nto a diffraction-limited spot immediately after the feedback loop was clos ed. (C) 2000 Optical Society of America. OCIS codes: 010.1080, 120.3180, 23 0.3720, 230.6120.