Numerical correction of aberrations via phase retrieval with speckle illumination

What we believe to be a novel technique for wavefront aberration measurement using speckle patterns is presented. The aberration correction is done numerically. A tilted lens is illuminated with a partially developed speckle field, and the transmitted light intensity is sampled at axially displaced planes. The speckle intensity patterns are then sent to a phase-retrieval algorithm to reconstruct the complete wavefront. The nature of the wavefront aberration is determined through Zernike polynomials. Numerical correction of the perturbed wavefront is performed based on rms error and the Strehl ratio. Restoration of the wavefront from a phase object with high spatial frequency content shows the effectiveness of our method. (C) 2009 Optical Society of America