Enhanced deterministic phase retrieval using a partially developed speckle field.
A technique for enhanced deterministic phase retrieval using a partially developed speckle field (PDSF) and a spatial light modulator (SLM) is demonstrated experimentally. A smooth test wavefront impinges on a phase diffuser, forming a PDSF that is directed to a 4f setup. Two defocused speckle intensity measurements are recorded at the output plane corresponding to axially-propagated representations of the PDSF in the input plane. The speckle intensity measurements are then used in a conventional transport of intensity equation (TIE) to reconstruct directly the test wavefront. The PDSF in our technique increases the dynamic range of the axial intensity derivative for smooth phase objects, resulting in a more robust solution to the TIE. The SLM setup enables a fast and accurate recording of speckle intensity. Experimental results are in good agreement with those obtained using the iterative phase retrieval and digital holographic methods of wavefront reconstruction.
National Institute of Physics, University of the Philippines, Quezon City 1101, Philippines. palmoro@nip.upd.edu.ph
Percival F
PF
Almoro
Laura
L
Waller
Mostafa
M
Agour
Claas
C
Falldorf
Giancarlo
G
Pedrini
Wolfgang
W
Osten
Steen G
SG
Hanson