Bound State in the Continuum Enabled Ultralong Silicon Waveguide Grating Antennas for Integrated LiDAR Applications

In this paper, we report two kinds of silicon ridge-waveguide-based waveguide grating antennas (WGAs) with ultra-sharp instantaneous field-of-view (IFOV) for light detection and ranging (LiDAR) applications. Lateral bound state in the continuum (L-BIC) is utilized to suppress side scattering and improves the emission efficiency. The WGAs are fabricated on silicon on insulator (SOI) platform with 220nm device layer and foundry compatible etching depths. The measured losses are as low as 2.64 and 2.40 dB/mm at the wavelength of 1550nm, and the measured beam divergence of WGAs with 6mm length are 0.0251° and 0.0237°. These low beam divergences WGAs are promising for high resolution LiDAR applications.