Spatial Light Modulators and Their Applications in Polarization Holography

Abstract

Liquid crystal spatial light modulators (LC-SLMs) have gained substantial interest of the research fraternity due to their remarkable light modulation characteristics in modern imaging applications. Replacing the conventional optical elements from the SLM-based computer-generated holograms (CGHs) is a trending approach in modern digital holographic applications due to the optimized phase shift depending on the phase modulation features of SLMs. Apparently; SLMs serve a crucial role in the experimental implementation of digital holographic techniques. However, the resolution of the CGHs are sometimes limited by the structural discrepancies (fill factor, spatial anomalies, refresh rate, etc.) of SLM. Therefore, it is recommended to calibrate the modulation characteristics of SLMs prior to their implementation for imaging applications. This chapter provides comprehensive literature (review) of the LC-SLMs along with their major calibration methods. In addition, recent interesting applications of LC-SLMs have been discussed thoroughly within the framework of polarization holography.

Vectorial liquid-crystal holography

“…It allows for a complete reconstruction of the wavefront of light [7][8][9][10][11]. To explore the full potential of multichannel optical communications and enhanced optical encryption, many efforts have been made in vectorial holography [12][13][14][15][16][17], which involves the manipulation of both polarization and amplitude in a spatially varying fashion. Among different methods, metasurfaces, consisting of subwavelength structure units, have been proven to be highly effective in engineering the waveform of electromagnetic waves with an unprecedented level of precision [18][19][20][21].…”

Polarization Diffraction Gratings in PAZO Polymer Thin Films Recorded with Digital Polarization Holography: Polarization Properties and Surface Relief Formation

“…These devices replace the object and allow the creation of an object wave with the desired parameters. SLMs are most commonly liquid crystal devices, where the rotation of the liquid crystal molecules with respect to the supplied voltage (gray level) provides the necessary phase modulation of the corresponding pixel [54,55]. SLM is used as a dynamic (programmable) device and has wide applications [54], such as optical tweezers [56], beam shaping [57], coded aperture [58], etc.…”