A Large-Scale Passive Optical Phase Array With 1024 Channels

Due to the advantages of fast scanning speed, good stability, flexible pointing, high resolution, small size and low cost, optical phased array has become a potential key component of beam scanners. The effective aperture of optical phased array determines properties such as divergence angles and ranging distance, and how to achieve it has been of interest to researchers. In this letter, we have designed and fabricated a 1024-channel passive optical phased array chip. A small divergence angle (0.05 $^{\circ }\,\,\times 0.04^{\circ }$ ) has been achieved by adopting a Si ₃ N ₄ perturbation grating structure on Si waveguide. Based on this chip, we have built a coherent detection demonstration system and carried out relevant experiments with it.