Wavefront-sensorless aberration correction of extended objects using a MEMS deformable mirror

Abstract

The original proposal of wavefront-sensorless aberration correction was suggested by Muller and Buffington[1]. In this technique we attempt to correct for wavefront aberrations without the use of conventional wavefront sensing. We apply commands to a corrective element with adjustable segments in an attempt to maximise a metric which correlates to image quality. We employ search algorithms to find the optimal combination of actuator voltages on a DM to maximise a certain sharpness metric. The "sharpness" is based on intensity measurements taken with a CCD camera. It has been shown that sharpness maximisation, using the simplex algorithm, can minimise the aberrations and restore the Airy rings of an imaged point source. This paper demonstrates that the technique can be applied to extended objects which have been aberrated using a Hamamatsu SLM to induce aberrations. The correction achieved using various search algorithms are evaluated and presented.