Computational sub-pixel phase retrieval from multiple phase-coded aperture patterns
Igor Shevkunov (Technological University of Tampere, Finland)
Computational sub-pixel phase retrieval is considered with a random phase modulation at the object plane. The optical setup is lensless with a spatial light modulator for aperture phase coding. The wavefront propagation is modeled using the angular spectrum transfer function. Multiple intensities recorded by the sensor are random due to the random phase modulation. Sparse modeling of amplitude and absolute phase of the object is one of the key elements of the derived method. It is shown by computational experiments that high-accuracy reconstructions can be achieved with sub-pixel resolution going up to 32 times smaller with respect to the sensor pixel size. Sub-pixel resolution is achieved by random illumination and computational enlargement of the aperture.