Photonic integrated circuit with multiple waveguide layers for broadband high-efficient on-chip 3-D optical phased arrays in light detection and ranging applications

TL;DR

This paper presents the first experimental demonstration of a true 3-D optical phased array using a multi-layer Si3N4/SiO2 platform, enabling broadband high-efficiency on-chip light detection and ranging applications.

Contribution

It introduces a novel multi-waveguide-layer PIC design for 3-D OPAs, expanding beyond traditional single-layer structures with proof-of-concept fabrication and testing.

Findings

Successful numerical simulation of the multi-layer 3-D OPA.

Fabrication and testing of proof-of-concept samples.

Potential for extended detection range in Lidar applications.

Abstract

Traditional photonic integrated circuit (PIC) inherits the mature CMOS fabrication process from the electronic integrated circuit (IC) industry. However, this process also limits the PIC structure to a single-waveguide-layer configuration. In this work, we explore the possibility of the multi-waveguide-layer PIC by proposing and demonstrating a true 3-D optical phased array (OPA) device, with the light exiting from the edge of the device, based on a multi-layer Si3N4/SiO2 platform. The multi-waveguide-layer configuration offers the possibility of utilizing edge couplers at both the input and the emitting ends to achieve broadband high efficiency. This uniqueness provides the potential for a more extended detection range in the Lidar application. The device has been studied by numerical simulation, and proof-of-concept samples have been fabricated and tested with a CMOS-compatible process. To the best of our knowledge, this is the first experimental proof-of-concept of a true 3-D OPA with a multi-waveguide-layer configuration all over the device.