  We demonstrate a one-dimensional optical phased array on an integrated
silicon platform for operation at 1.55 microns. Light is emitted end-fire from
the chip edge where the waveguides are terminated. The innovative design and
high confinement afforded by the silicon waveguides enables lambda/2 spacing
(775-nm pitch) at the output. Steering is achieved by inducing a phase shift
between the waveguides via integrated thermo-optic heaters. The device forms a
beam with a FWHM angular width of 17 degrees, and we demonstrate beam steering
over a 64 degrees range.
