Interferometry using deterministic phase retrieval and speckle illumination

Abstract

An interferometric method for the evaluation of reconstructed wavefronts obtained via deterministic phase retrieval with speckle illumination is demonstrated numerically and experimentally. A refractive sample is illuminated with a partially-developed speckle field, and the transmitted light is detected. The phases corresponding to different object loading states are calculated using the transport-of-intensity equation. The difference between retrieved phase maps is then used to evaluate the refractive index change due to mechanical loading.