Resonance-enhanced integrated acousto-optic beam steering

TL;DR

This paper presents a resonance-enhanced integrated acousto-optic beam steering device on a lithium niobate platform, achieving high efficiency and enabling dynamic FMCW LiDAR operation through co-integrated acousto-optic and electro-optic functionalities.

Contribution

It introduces a novel integrated acousto-optic beam steering device with resonance enhancement and electro-optic control on a TFLN platform, advancing compactness and multifunctionality.

Findings

Achieved up to 20% beam steering efficiency over 18 degrees.

Enabled dynamic resonance locking for FMCW LiDAR.

Demonstrated integration of acousto-optic and electro-optic functionalities.

Abstract

Optical beam steering is a key technology for free-space optical communication, sensing, and imaging. Mechanical beam steering systems suffer from limited scanning speed and bulky form factors, while existing solid-state solutions rely on pixelated synthetic aperture that requires complex fabrication and control architectures. Integrated acousto-optic beam steering (AOBS) is an emerging technology that enables continuous one-dimensional beam steering using integrated acoustic transducers and fixed-wavelength laser sources. Here, we integrate AOBS with an optical ring resonator on the same thin-film lithium niobate (TFLN) platform to significantly enhance beam steering efficiency and system functionality. The resulting device achieves a resonance-enhanced beam steering efficiency of up to 20% over a 18 degrees field of view. Moreover, by leveraging integrated electro-optic control, we dynamically lock the ring-resonator's resonance to a chirped laser frequency, enabling frequency-modulated continuous-wave (FMCW) LiDAR operation. By combining lithium niobate's piezoelectric and electro-optic properties, this work establishes a compact, efficient, and scalable beam-steering platform with co-integrated acousto-optic modulation and electro-optic control for multifunctional applications.