High-Q photonic resonators and electro-optic coupling using silicon-on-lithium-niobate

TL;DR

This paper demonstrates high-Q silicon-on-lithium-niobate resonators and electro-optic modulation, advancing integrated photonics for quantum networks and other applications by achieving high quality factors and effective resonance tuning.

Contribution

It presents the fabrication and characterization of high-Q resonators and electro-optic modulation in a silicon-on-lithium-niobate platform, a novel approach for quantum and classical photonics.

Findings

Optical quality factors up to 730,000 achieved

Resonance frequency modulated with 1-2 pm/V electro-optic coefficient

Propagation loss of 0.8 dB/cm in resonators

Abstract

Future quantum networks in which superconducting quantum processors are connected via optical links, will require microwave-to-optical photon converters that preserve entanglement. A doubly-resonant electro-optic modulator (EOM) is a promising platform to realize this conversion. Here, we present our progress towards building such a modulator by demonstrating the optically-resonant half of the device. We demonstrate high quality factor ring, disk and photonic crystal resonators using a hybrid silicon-on-lithium-niobate material system. Optical quality factors up to 730,000 are achieved, corresponding to propagation loss of 0.8 dB/cm. We also use the electro-optic effect to modulate the resonance frequency of a photonic crystal cavity, achieving a electro-optic modulation coefficient between 1 and 2 pm/V. In addition to quantum technology, we expect that our results will be useful both in traditional silicon photonics applications and in high-sensitivity acousto-optic devices.