Corrugated Waveguide-Based Optical Phased Array With Crosstalk Suppression

We present the corrugated waveguide as a free space grating coupler for use in optical phased arrays for large angle optical beam steering. Compared with conventional shallow etched gratings, the corrugated waveguide requires only a single patterning step while achieving lithographically defined index contrast. We achieve 15° of steering with wavelength tuning, with an average longitudinal beam width of 0.3°. To prevent optical crosstalk from grating-assisted coupling in a corrugated waveguide array with small element spacing, the photonic bandgap of a 2D photonic crystal is used to optically isolate each array element in a 16 element array.