Wide-Angle Beam-Steering Using an Optical Phased Array with Non-Uniform-Width Waveguide Radiators

We demonstrate wide-angle beam-steering using an optical phased array (OPA) with waveguide radiators designed with non-uniform widths to reduce the crosstalk between waveguides. The OPA consists of a silicon based 1 x 16 array of electro-optic phase shifters and end-fire radiators. The 16 radiators were configured with four different widths and a half-wavelength spacing, which can remove the higher-order diffraction patterns in free space. The waveguides showed a low crosstalk of -10.2 dB at a wavelength of 1540 nm. With phase control, the OPA achieved wide beam-steering of over +/- 80 degrees with a side-lobe suppression of 7.4 dB.