Phased Array, Integrated Optical Beam Steering Device

Abstract

In this paper we demonstrate a phased array integrated optical beam steering device for sensing and analyze the efficiency of using thermo optic heaters to manipulate the phase of the signal in each waveguide to produce a steering effect in the far field. The designed silicon nitride waveguide array has eight arms that must be controlled individually. Manufacturing variations cause the fabricated device performance to deviate from the nominal design behavior. An algorithm was formulated to attain the optimal phases for each arm to steer the beam, the algorithm performed as expected but significant amount of drift appears in the output, potentially due to the temperature gradient presented on each channel. A temperature stabilization system was attached to the chip to minimize the drift, and to better characterize the behavior of the beam we including an IR camera to view the near and far fields. The algorithm proved effective by improving the intensity of the main beam, and steering the beam to our target location.