Two-dimensional polarization encoding with a phase-only liquid-crystal spatial light modulator

TLDR

Techniques exist to rotate the major axis of elliptically polarized light or convert a linearly polarized beam into arbitrary elliptically polarized light, with several potential applications. The study demonstrates two‑dimensional encoding of incident light polarization using a parallel‑aligned liquid‑crystal spatial light modulator. Each LCSLM pixel functions as a voltage‑controlled wave plate, programmable over a 2π phase range at 514.5 nm, enabling the encoding. Experiments produce diverse two‑dimensional polarized light patterns and reveal an unexpected edge‑enhancement effect useful for image processing.

Abstract

We show how to two dimensionally encode the polarization state of an incident light beam using a parallel-aligned liquid-crystal spatial light modulator (LCSLM). Each pixel of the LCSLM acts as a voltage-controlled wave plate and can be programmed over a 2π phase range at a wavelength of 514.5 nm. Techniques are reviewed for either rotating the major axis of elliptically polarized light or for converting an input linearly polarized beam into an arbitrary elliptically polarized beam. Experimental results are demonstrated in which we generate various two-dimensional spatial patterns of polarized light. Several potential applications are suggested. We also report an unexpected edge-enhancement effect that might be useful in image processing applications.