We developed an optical phased array incorporating a single-layer high-index-contrast sub- wavelength grating (HCG) for 2D beamsteering. There are a number of other approaches for optical phased arrays such as liquid-crystal-based phased arrays and microelectromechanical system (MEMS) phased array. Switching of liquid-crystal based phased arrays typically takes on the order of milliseconds. Arrays of MEMS mirrors moving perpendicular to the substrate are usually made of silicon so that a metal-coated layer is required on top, resulting in thermal induced stress when very high optical power application (~10 W) is applied. Our approach needs only a thin single-layer HCG made of silicon, widening its application in terms of high optical power, thanks to the highly reflective HCG across a wide bandwidth, and considerably improving its speed due to the low mass of the thin HCG. The measured resonant frequency of MEMS mirrors was 0.46 MHz. The 2D beamsteering angle was from -10 degrees to +10 degrees in both directions.
Project end date: 02/03/14