Demonstration of 3-dimensional wide angle laser beam scanner using liquid crystals

Abstract

Design and demonstration of a versatile liquid crystal-based scanner is shown for steering a laser beam in three dimensions. The scanner consists of a unique combination of digital and analog control polarization-based beam forming optics resulting in both continuous and random fashion beam steering. The design features a novel device biasing method, large aperture beam-forming optics, low electrical power consumption, and ultrafine as well as wide angle coarse beam steering. Demonstrations include one, two and three dimensional beam steering with a maximum of 40.92 degree continuous scan, all at 1550 nm. The minimum scanner aperture is 1 cm diameter and uses a combination of ferroelectric and nematic liquid crystals in addition to Rutile crystal birefringent prisms.

High Birefringence Liquid Crystals

“…They are connected with telecommunication devices needs or nondestructive microwaves apparatus to control goods and people [19], cholesteric lasers [20,21], manufacturing tunable metamaterial [22][23][24][25]. Different devices such as tunable spatial modulators for light and laser beam steering and for holography [26][27][28][29][30][31][32][33], switchable phase shifters [34][35][36], various types of tunable filters which select or remove bands [37][38][39][40], tunable capacitors [41], antennas [42], lenses [43,44] were manufactured, and others such as photonic fiber [45] (see also, for more information, reviewed papers [46,47]). For these purposes, different high birefringence materials from 0.2 to more than 0.5 are now available [48][49][50][51][52], but further development and improvement of their properties is still necessary.…”

Liquid-crystal photonic applications

“…A first approach is based on the spatial polarization separation induced by birefringent prisms. 71,72 A liquid-crystal OPA first deflects the beam under a small angle toward a cascade of birefringent prisms. Before each prism, the polarization state of the incident light is controlled by a tunable liquid-crystal layer.…”

Laser-based satellite communication systems stabilized by non-mechanical electro-optic scanners

“…Past approaches going back decades have utilized tunable diffraction gratings, such as liquid crystal (LC) optical phased arrays (OPAs), [7][8][9][10][11][12][13] MEMs arrays, 14, 15 electro-wetting arrays, 16 and acousto-optics. Despite significant advances, inherent limitations remain such as excessive dispersion due to diffraction, excessively long search times of up to several minutes, and poor coverage leading to blind spots in the FOV.…”