In this letter published in Optics Letters on May 3, 2016, the group proposes a phase retrieval technique where the set-up uses a spatial light modulator (SLM) as a diffuser to enhance the variation in the intensity of light. Using an SLM and an analyzer, the phase information is efficiently encoded due to the filetring of the polarization states. This method was demostrated and verified experimentally using wave propagation and Jones calculus. One advantage of this method is it is very easy to implement.
In the multiple-plane phase retrieval method, a tedious to fabricate phase diffuser plate is used to increase the axial intensity variation for a nonstagnating iterative reconstruction of a smooth object wavefront. Here we show that a spatial light modulator (SLM) can be used as an easily controllable diffuser for phase retrieval. The polarization modulation at the SLM facilitates independent formation of orthogonally polarized scattered and specularly reflected beams. Through an analyzer, the polarization states are filtered enabling beam interference, thereby efficiently encoding the phase information in the axially diverse speckle intensity measurements. The technique is described using wave propagation and Jones calculus, and demonstrated experimentally on technical and biological samples.
Percival F. Almoro, Quang Duc Pham, David Ignacio Serrano-Garcia, Satoshi Hasegawa, Yoshio Hayasaki, Mitsuo Takeda, and Toyohiko Yatagai, “Enhanced intensity variation for multiple-plane phase retrieval using a spatial light modulator as a convenient tunable diffuser,” Opt. Lett. 41, 2161-2164 (2016)