Two-Dimensional Scanning Liquid Crystal Infrared Reflect Array

Abstract

We present a new reflectarray technology capable of scanning in two dimensions. The device is a reflective semiconductor chip composed of small two-stage phase delay cavities filled with electrically biased liquid crystal. The scanning is enabled by changes in the AC electrical bias, which modifies the effective dielectric constant of the liquid crystal. This enables each cavity to delay the fields in each stage by as much as 360 degrees. As a result, the two-stage cavity allows nearly independent scanning in two orthogonal planes. The structure operates at a wavelength of 1550nm and is manufactured using a standard damascene process.