Two-dimensional free-space beam steering with an optical phased array on silicon-on-insulator
The robustness, speed, and compactness of optical beam-steering techniques can be greatly enhanced by transitioning from mechanical beam control (e.g. adaptive mirrors) to a phased-array approach, similar to the transition made in the 20th century with respect to radar. In particular, point-to-point free-space communication links, Light Detection and Ranging (LIDAR), and optical memory benefit from a chip-scale beam steerer without moving parts which can be readily integrated with control electronics on the same chip. At UCSB we used standard CMOS-compatible processing techniques to produce an independently phase-tuned grating-coupled waveguide array in silicon for 2D beam steering over a 14⁰ x 20⁰ field of view with 10 dB background suppression and 0.6⁰ x 1.6⁰ beam width.
Top left: Optical phased array with independent phase control in silicon-on-insulator (SOI).
Top right: Scanning electron microscope (SEM) image of the waveguide surface grating array.
Bottom: Measured optical power in the far field with the beam steered to five points in the field of view.
Associated publications:
"Two-dimensional free-space beam steering with an optical phased array on silicon-on-insulator," J. K. Doylend, M. J. R. Heck, J. T. Bovington, J. D. Peters, L. A. Coldren, and J. E. Bowers, Optics Express, 19, 22, pp. 21595-21604, October 18, (2011).
"Free-space Beam Steering Using Silicon Waveguide Surface Gratings," J. K. Doylend, M. J. R. Heck, J. T. Bovington, J. D. Peters, and J. E. Bowers,2011 IEEE Photonics Conference, WR6, Arlington, VA, October 12, (2011).
