Multi-Channel Microwave-to-Optics Conversion Utilizing a Hybrid Photonic-Phononic Waveguide

TL;DR

This paper presents a novel multi-channel microwave-to-optics converter using a hybrid photonic-phononic waveguide on lithium niobate, achieving broad bandwidth and simultaneous multiple channel operation at room temperature.

Contribution

Introduces the first traveling-wave architecture for multi-channel microwave-to-optics conversion leveraging continuous phase-matching on TFLN, enabling high bandwidth and multiple simultaneous channels.

Findings

Achieves over 40 nm optical bandwidth and 250 MHz microwave bandwidth.

Demonstrates nine concurrent conversion channels in a single device.

Attains 2.2% internal efficiency at room temperature.

Abstract

Efficient and coherent conversion between microwave and optical signals is crucial for a wide range of applications, from quantum information processing to microwave photonics and radar systems. However, existing conversion techniques rely on cavity-enhanced interactions, which limit the bandwidth and calability. Here, we demonstrate the first multi-channel microwave-to-optics conversion by introducing a traveling-wave architecture that leverages a hybrid photonic-phononic waveguide on thin-film lithium niobate (TFLN). Our approach exploits continuous phase-matching rather than discrete resonances, enabling unprecedented operational bandwidths exceeding 40 nm in the optical domain and 250 MHz in the microwave domain. By harnessing the strong piezoelectric and photoelastic effects of TFLN, we achieve coherent conversion between 9 GHz microwave photons and 1550 nm telecom photons via traveling phonons, with an internal efficiency of 2.2% (system efficiency 2.4 *10^-4 ) at room temperature. Remarkably, we demonstrate simultaneous operation of nine conversion channels in a single device. Our converter opens up new opportunities for seamless integration of microwave and photonic technologies, enabling the quantum interface for distributed quantum computing with superconducting quantum processors, high efficient microwave signal processing, and advanced radar applications.