Generating multiple polarization outputs using random binary patterns with cascaded spatial light modulators

In this work we apply an optical system with two cascaded liquid-crystal spatial light modulators (LC-SLMs) to produce multiple outputs with intensity and polarization control. We use a non-standard modulation configuration where the first LC-SLM operates as a phase-only modulator to encode a Fourier transform hologram multiplexing the desired multiple output beams, all with the same polarization. Next, the Fourier transform is optically formed onto the second LC-SLM, where each output beam is focused on different physical locations. The two SLMs have the LC director axis oriented horizontally. Thus, by rotating the linearly polarized output beams emerging from the first LC-SLM by 45 deg, we operate the second LC-SLM as a variable retarder. Then, by applying different phase-shifts at the different areas of the second LC-SLM, we can vary the polarization state of each output beam. Finally, the output is imaged onto a camera detector to demonstrate the polarization states. Experimental results demonstrate the capability for this approach to encode a variety of output beams with different states of polarization.