Reconfigurable Geometrical Phase Spatial Light Modulator Using Short‐Pitch Ferroelectric Liquid Crystals
Zhibo Sun, Zhengnan Yuan, V. Swaminathan, Valerii V. Vashchenko, Elena V. Vashchenko, Alex Cheung, Lei Lü, Hoi Sing Kwok, Abhishek Kumar Srivastava
Abstract
Abstract This article presents an approach to achieve a fast and analog geometrical phase modulation based on the optical axis rotation of the defect‐free Deformed Helix Ferroelectric Liquid Crystal (DHFLC) with a short pitch. This study demonstrates a Spatial Light Modulator (SLM) prototype with a feature size of 3 µm without Fringe Field Effect (FFE), having a phase depth of 1.9π, fast switching time (<250 µs) at a low operating voltage (<7 V), and high diffraction efficiency (>77%). The high phase modulation depth is achieved by developing DHFLC with a cone angle of up to 85˚, which is inherently immune to FFE. The ellipticity is minimized by using a compensation film that can suppress the changes in birefringence under the applied electric field. The proposed SLM is promising in applications such as a real‐time hologram and dynamic beam steering in Light Ranging and Detector (LiDAR).