High efficiency end-fire 3-D optical phased array based on multi-layers Si3N4/SiO2 platform

TL;DR

This paper presents a multi-layer Si3N4/SiO2 platform enabling a high-efficiency 3-D optical phased array with wide horizontal beam steering, addressing energy loss issues in traditional single-layer OPAs.

Contribution

It introduces a novel multi-layer structure for 3-D OPAs that significantly improves efficiency and beam steering capabilities compared to existing single-layer designs.

Findings

Achieved high efficiency and wide horizontal beam steering numerically.

Analyzed the effects of vertical cross-talk, delay length, and layer number.

Discussed fabrication feasibility of the multi-layer structure.

Abstract

Beam steering device such as optical phased array (OPA) is a key component in applications of solid-state Lidar and wireless communication. The traditional single-layer optical phased array (OPA) results in a significant energy loss due to the substrate leakage caused by the downward coupling from the grating coupler structure. In this work we have investigated a structure based on multi-layers Si3N4/SiO2 platform that can form a 3-D OPA to emit the light from the edge of the device with high efficiency, a 2-D converged out-coupling beam will be end-fired to the air. The high efficiency and wide horizontal beam steering are demonstrated numerically, the influence of vertical cross-talk, the delay length, number of waveguide layers, and the fabrication feasibility are also discussed.