Pseudorandom phase-only encoding of real-time spatial light modulators

Area of Science:

• Optics and Photonics
• Information Optics

Background:

• Spatial light modulators (SLMs) are crucial for optical information processing.
• Encoding full-complex spatial modulations onto phase-only SLMs is challenging due to device limitations.

Purpose of the Study:

• To investigate a method for mapping full-complex spatial modulations to phase-only modulations.
• To experimentally validate the proposed pseudorandom encoding technique.

Main Methods:

• Utilized pseudorandom encoding to represent complex modulation amplitudes via phase variations.
• Employed a phase-only spatial light modulator with a limited phase shift (326°) for experimental validation.
• Performed Fourier transform analysis to compare encoded and original modulations.

Main Results:

• The Fourier transform of the encoded modulations approximated that of the original complex modulations.
• Qualitative agreement between theoretical predictions and experimental results was achieved.
• The limitations of the 326° modulator introduced nonideal properties impacting the results.

Conclusions:

• The pseudorandom encoding method is a viable approach for mapping complex modulations to phase-only SLMs.
• Experimental validation confirms the theoretical principles, despite hardware limitations.
• Further improvements can be expected with SLMs offering a full 360° phase shift.