We report an independently tuned 16-channel optical phased array fabricated in silicon for 2D free-space beam steering. The phased array was composed of silicon-on-insulator waveguide surface gratings integrated with thermo-optic phase tuners and was operated both using a control algorithm together with automated real-time far field image analysis to target and shape the beam, and using a lookup table without real-time feedback. The device exhibited 1.6° ⨉ 0.6° beam width and 10 dB background suppression in the far field across a 20° ⨉ 14° field of view. We show that by increasing the waveguide width from 1 μm to 3 μm we can suppress the side- lobe peaks by a factor of 2.
© 2012 Optical Society of AmericaPDF Article