Wide-angle, nonmechanical beam steering with high throughput utilizing polarization gratings

Abstract

We introduce and demonstrate a ternary nonmechanical beam steering device based on polarization gratings (PGs). Our beam steering device employs multiple stages consisting of combinations of PGs and wave plates, which allows for a unique three-way (ternary) steering design. Ultrahigh efficiency (∼100%) and polarization sensitive diffraction of individual PGs allow wide steering angles (among three diffracted orders) with extremely high throughput. We report our successful demonstration of the three-stage beam steerer having a 44° field of regard with 1.7° resolution at 1550 nm wavelength. A substantially high throughput of 78%-83% is observed that is mainly limited by electrode absorption and Fresnel losses.

Nonmechanical Laser Beam Steering Based on Polymer Polarization Gratings: Design Optimization and Demonstration

“…It is possible to configure PG steering designs that are based on either switchable [13], [14] or polymer [15] PGs. These designs all utilize at least one switchable LC variable retarder as the polarization selector/controller before each PG, which is needed to access the full FOR.…”

“…With the three PGs prepared and three switchable LC WPs [14] optimized for 1550 nm wavelength (fabricated in-house), we assembled the 1D coarse steering module shown as the Fig. 4 with the order of PG3 (adjacent to the input), PG2, and PG1 consecutively.…”

“…In order to realize a fast and low loss nonmechanical beam steering, we introduced a technique based on switchable polarization gratings (PGs) [13], [14]. This technique utilizes a stack of switchable PGs and waveplates (WPs).…”

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

“…In 2006, Escuti et al demonstrated defect-free, 100% efficient PGs as switchable diffractive elements. 5,6 Since these devices are not traditional gratings they exhibit very large acceptance angles while maintaining near 100% diffraction efficiency into a single order. This counterintuitive property is critical to our design.…”

A Simplified Model for the Optimization of LC Photonic Elements

“…The polarization state of the transmitted electric field is thus modulated periodically [1]. Because of its well-known interesting optical properties [2]- [5], a variety of applications have been proposed, including displays [6], polarimeters for measuring stokes parameters [7], [8] or Muller matrix [9], beam steering [10], [11], polarization conversion element [12] etc.…”