High-Efficiency, Wide Working Bandwidth Antenna Based on SOI Platform for Optical Phased Array.

A novel structure of a subwavelength surface optical antenna for optical phased array is proposed in this paper. An asymmetric vertical grating structure is applied to achieve high emission efficiency (73% at 1550 nm). Optical antennas with large fabrication tolerances can also maintain a wide working bandwidth of 1 dB between 1350 and 1850 nm. The far-field scanning characteristics of 16-channel optical phased array are investigated in this study by employing the proposed antenna. The results show that the background suppression without considering side lobes caused by the antenna arrangement is -24.5 dB when the phase difference is 0 and when the scan range is as large as ±14.8° × 73.6°.