Regular papers

Investigation of smooth wave fronts using SLM-based phase retrieval and a phase diffuser

¹ Bremer Institut für angewandte Strahltechnik, Klagenfurter Strasse 2, 28359 Bremen, Germany
² Physics Department, Faculty of Science, Aswan University, 81528 Aswan, Egypt
³ National Institute of Physics, University of the Philippines, Diliman, Quezon City, 1101 Philippines

^* agour@bias.de

Received: 16 July 2012
Revised: 24 October 2012

Abstract

A phase retrieval technique using a spatial light modulator (SLM) and a phase diffuser for a fast reconstruction of smooth wave fronts is demonstrated experimentally. Diffuse illumination of a smooth test object with the aid of a phase diffuser (maximum phase shift, Δø = 0.85π) results in a significant diversity in the intensity measurements which, in turn, is beneficial for a non-stagnating iterative phase reconstruction. The use of the SLM enables accurate and fast speckle intensity recording and active correction of misalignments in the setup. The effectiveness of the technique is demonstrated in the optical testing of lenses.