Liquid Crystal on VLSI Silicon Optical Phased Array

Several applications for solid-state, random access beam directors have emerged in recent years, including scanners, laser radar components, interconnects, elements for addressing holographic storage, beam routing devices, and adaptive switching networks. We discuss implementation of optical phased arrays using a liquid crystal on silicon approach. By using very large scale integration (VLSI) technology, each element of the array is individually addressable. This allows the device to spatially correct both static and dynamic phase distortions as it steers the beam (or field of regard). In addition, this technology lends itself to the possibility of scaling to large (several centimeters) aperture. Currently VLSI foundries are pushing for small feature size and higher operating voltages. These ongoing developments in integrated circuit fabrication processes result in devices exhibiting excellent electrical performance, but poor optical quality. Increased reflectivity and planarization are necessary to produce high efficiency beam steering devices. Steps taken to improve optical performance of silicon backplanes will also be discussed.