1 x 12 Unequally spaced waveguide array for actively tuned optical phased array on a silicon nanomembrane

We present an experimental demonstration of an optical phased array implementation on silicon nanomembrane. The integrated on-chip array configuration is non-uniform and avoids grating lobes inside the field of view during beam steering while allowing the waveguide separation to be large enough to prevent optical coupling. A 1 x 12 multimode interference beam splitter uniformly excites the arrayed waveguides. Individually controllable micro-heaters modulate the optical phase in the arrayed waveguides. A beam steering angle of 10.2 degrees in a silicon planar guide equivalent to an effective steering angle of 31.9 degrees in air is demonstrated at 1.55 mu m. (C) 2011 American Institute of Physics. [doi:10.1063/1.3619847]