Taper-tip double-layer grating antenna based on SiN-on-SOI with large scale-scanning range for LiDAR

Abstract

In this article, with the objective of reducing the emission loss, enhancing the emission directionality and scale-scanning range, without increasing the complexity of the LIDAR system, a CMOS-compatible silicon nitride taper-tip double-layer auxiliary grating antenna is proposed and investigated systematically. Compared to conventional double layer grating, the directionality exceeds 72% for wavelengths from 1450 nm to 1600 nm, with a maximum directionality of 97.5% at 1550 nm. Therefore, the far-field divergence angle of 0.0081° × 0.03° and a large field of view of 108.45° × 23.43° can be achieved when the antenna aperture is 1.6 cm × 2.5 cm. These improvements come mainly from the increasing unidirectional emission performance of the phased array by adjusting the key structural parameters of the inverted taper-tip double-layer structure.