Circular optical phased array for 360° constant amplitude scanning

Optical phased arrays (OPAs) are widely used in many applications to realize high-speed optical beam scanning. At present OPAs often suffer from limited scanning range. Here we propose a circular optical phased array (COPA) based on silicon photonics platform. According to our simulations, by positioning the OPA units in a circle and adopting a specific phase distribution, the COPA can realize 360° constant amplitude scanning. In addition, the design of the disk grating coupler, which is the key device of the COPA, is presented. The COPA is believed to have great potential for applications where a wide scanning range is mandatory.