Electro-optically tunable microring resonators in lithium niobate

TL;DR

This paper reports the first realization of electro-optically tunable microring resonators in lithium niobate thin films, enabling advanced integrated optical devices with tunable properties for photonics applications.

Contribution

It demonstrates the fabrication and electro-optic tuning of lithium niobate microring resonators in submicrometric films, a novel achievement in integrated photonics.

Findings

Resonators with 100 um radius successfully fabricated.

Transmission spectra can be tuned via electro-optic effect.

Results enable new integrated optical device functionalities.

Abstract

Optical microresonators have recently attracted a growing attention in the photonics community. Their applications range from quantum electro-dynamics to sensors and filtering devices for optical telecommunication systems, where they are likely to become an essential building block. The integration of nonlinear and electro-optical properties in the resonators represents a very stimulating challenge, as it would incorporate new and more advanced functionality. Lithium niobate is an excellent candidate material, being an established choice for electro-optic and nonlinear optical applications. Here we report on the first realization of optical microring resonators in submicrometric thin films of lithium niobate. The high index contrast films are produced by an improved crystal ion slicing and bonding technique using benzocyclobutene. The rings have radius R=100 um and their transmission spectrum has been tuned using the electro-optic effect. These results open new perspectives for the use of lithium niobate in chip-scale integrated optical devices and nonlinear optical microcavities.