Toward scalable and bias-stable optical phased arrays on lithium tantalate

TL;DR

This paper demonstrates a bias-stable, scalable optical phased array on lithium tantalate, significantly improving phase stability and enabling practical applications in various advanced photonic systems.

Contribution

It introduces a novel lithium tantalate-based PIC platform that achieves bias stability and scalability, overcoming phase drift issues in ferroelectric photonic devices.

Findings

OPA maintains main lobe 8 dB higher than side lobes for over 4 hours

Device generates arbitrary waveforms at 0.1 Hz modulation frequency

Establishes LT as a high-speed, bias-stable PIC platform for large-scale systems

Abstract

Ferroelectric materials are an ideal platform for high-speed reconfigurable photonic integrated circuits (PICs) for classical and quantum photonic computations, communications, and sensing. Most reconfigurable PIC devices achieve their functionalities via interference and are therefore highly sensitive to phase errors. Under static bias, carrier drift in ferroelectric waveguides induces continuous phase drift, creating a severe bottleneck for both PIC functionality and scalability. Here we propose achieving bias-stable and scalable ferroelectric PICs by exploiting the intrinsically low carrier drift of lithium tantalate (LT). Taking one of the PIC devices that is most sensitive to phase drift, the optical phased array (OPA), as an example, we designed and fabricated an integrated LT OPA that can keep the far-field main lobe 8 dB higher than side lobes for over 4 hours, representing at least a two-order-of-magnitude improvement over the state of the art. We demonstrated our device's capability in generating arbitrary spatiotemporal waveforms with a modulation frequency as low as 0.1 Hz, leading to practical applications in optical tweezers, trapped-ion quantum computers, adaptive optics for astronomy, AR, 3D printers, LiDAR, and free-space optical communications. Beyond OPA, our work establishes LT as a bias-stable, scalable, and high-speed PIC platform for large-scale classical and quantum photonic systems.