Phase retrieval methods for adaptive optics correction with diffractive samples

Abstract

Extension of adaptive optics (AO) techniques to future data storage applications requires consideration for light reflected off a diffractive surface. Simulations and experiments are presented to study the efficacy of various wavefront reconstruction methods for examining diffractive samples. Image processing techniques are applied as an alternative to a Shack-Hartmann wavefront sensor. A modified Gerchberg reconstruction algorithm is used to gather wavefront data from multiple image acquisitions at different defocus positions. Furthermore, these multiple images are gathered simultaneously with a single acquisition using the concept of phase retrieval with complex diversity. A computergenerated hologram (CGH) is designed, fabricated, and implemented experimentally for single-shot AO correction.