Modified Strehl ratio for quantitative evaluation of speckle development

Abstract

Conventional Strehl method uses intensity ratio to evaluate aberrations on lens-based systems under plane wave illumination. Here we present a technique based on the Strehl method to evaluate the development of diffuse light or speckle pattern. A model for the proposed speckle evaluation technique is presented. The effectiveness of the technique is demonstrated on different diffusers (amplitude- and phase-type), varying object roughness or depth of randomization and varying shapes for the region of interest. The modified Strehl method offers a simple yet fast characterization of speckle development.