Liang J, Wu SY, Fatemi FK, Becker MF. Suppression of the zero-order diffracted beam from a pixelated spatial light modulator by phase compression.
APPLIED OPTICS 2012;
51:3294-304. [PMID:
22695563 DOI:
10.1364/ao.51.003294]
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Abstract
Phase compression is used to suppress the on-axis zero-order diffracted (ZOD) beam from a pixelated phase-only spatial light modulator (SLM) by a simple modification to the computer generated hologram (CGH) loaded onto the SLM. After CGH design, the phase of each SLM element is identically compressed by multiplying by a constant scale factor and rotated on the complex unit-circle to produce a cancellation beam that destructively interferes with the ZOD beam. Experiments achieved a factor of 3 reduction of the ZOD beam using two different liquid-crystal SLMs. Numerical simulation analyzed the reconstructed image quality and diffraction efficiency versus degree of phase compression and showed that phase compression resulted in little image degradation or power loss.
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