Analysis of optical beam steering using phased micromirror arrays

Beam steering using a phased array of emitters is quite common in radar applications. However, the concept of phased array is equally valid at optical wavelengths. At these wavelengths, the beam steerers can consist of arrays of phase modulators which are space-fed; that is, a uniform-phase optical beam is incident on the array, and the modulators impart the required phase shift to effect steering. One potential method of implementing such an optical phased array is through the use of flexure-beam micromirrors. We present an analysis of examples of such arrays. We compare the steering efficiency of two different arrays, one of which is an array of square mirrors, and one of which is an array of a smaller number of rectangular mirrors. The effects of deviation of the mirrors from a pure piston phase shift is also discussed. Optical beam steering using micromirror arrays is compared to other beam steering techniques.