Direct-Solve Image-Based Wavefront Sensing

A method of wavefront sensing (more precisely characterized as a method of determining the deviation of a wavefront from a nominal figure) has been invented as an improved means of assessing the performance of an optical system as affected by such imperfections as misalignments, design errors, and fabrication errors. Unlike some prior methods, this method does not require the use of an expensive, complex interferometric instrument for testing the optical system of interest: indeed, if the system under test includes an image sensor at its focal plane, then this method does not require any optical instrumentation other than the optical system under test. Unlike some other prior methods, this method does not involve processing of multiple defocused images by a nonlinear iterative phase-retrieval algorithm and interpretation of results by a human expert in phase retrieval. Instead, this method involves a single non-iterative algorithm that solves for the wavefront from a single in-focus image, without need for interpretation of results. Hence, the main advantages of this method over the prior methods are reduced computing time and reduced labor.