Beam Steering with Ultracompact and Low-Power Silicon Resonator Phase Shifters

TL;DR

This paper presents ultracompact, low-power silicon resonator phase shifters for photonic phased arrays, enabling scalable, energy-efficient beam steering suitable for long-distance laser communication.

Contribution

Introduction of thermally tuned microring resonator phase shifters with calibration techniques for scalable, low-power PIC phased arrays.

Findings

Achieved beam steering with a 1x8 array using microring resonator phase shifters.

Resonators consume only 0.4 mW power and provide large, adjustable phase shifts.

Demonstrated potential for ultra-large scale, low-power photonic phased arrays.

Abstract

Photonic integrated circuit (PIC) phased arrays can be an enabling technology for a broad range of applications including free-space laser communications on compact moving platforms. However, scaling PIC phased arrays to a large number of array elements is limited by the large size and high power consumption of individual phase shifters used for beam steering. In this paper, we demonstrate silicon PIC phased array beam steering based on thermally tuned ultracompact microring resonator phase shifters with a radius of a few microns. These resonators integrated with micro-heaters are designed to be strongly coupled to an external waveguide, thereby providing a large and adjustable phase shift with a small residual amplitude modulation while consuming an average power of 0.4 mW. We also introduce characterization techniques for the calibration of resonator phase shifters in the phased array. With such compact phase shifters and our calibration techniques, we demonstrate beam steering with a 1x8 PIC phased array. The small size of these resonator phase shifters will enable low-power and ultra-large scale PIC phased arrays for long distance laser communication systems.