High-directionality SiN-assisted grating antenna for optical phased array

In the realm of consumer electronics, automotive, and robotics, lidar has proven to be a valuable technology. However, current lidar solutions such as mechanical, microelectromechanical, and flash lidar are associated with drawbacks such as high cost, low resolution, and a limited ranging distance. To address these issues, optical phased array (OPA) technology has been proposed as a promising solution due to its high resolution, rapid response times, long ranging distance, and low cost. Despite these advantages, OPA is still in the developmental stages and further optimization is required to address issues such as loss, field of view (FOV), and beam divergence. To address the FOV and beam divergence issues, SiN-assisted grating antenna has been used. However, the directionality of an SiN-assisted antenna is relatively low and may introduce additional loss for OPA. To overcome this limitation, this paper proposes a dual-layer SiN-assisted grating antenna with more than 94% directionality in 1550 nm. Moreover, the wavelength bandwidth of more than 90% directionality is over 80 nm, making it a promising solution for OPA devices.