Sparse aperiodic arrays for optical beam forming and LIDAR

We analyze optical phased arrays with aperiodic pitch and element-to-element spacing greater than one wavelength at channel counts exceeding hundreds of elements. We optimize the spacing between waveguides for highest side-mode suppression providing grating lobe free steering in full visible space while preserving the narrow beamwidth. Optimum waveguide placement strategies are derived and design guidelines for sparse (> 1.5 lambda and > 3 lambda average element spacing) optical phased arrays are given. Scaling to larger array areas by means of tiling is considered. (C) 2017 Optical Society of America