We demonstrate waveguide-coupled titanium dioxide (TiO2) racetrack resonators with loaded quality factors of 2x10^4 for the visible wavelengths. The structures were fabricated in sputtered TiO2 thin films on oxidized silicon substrates using standard top-down nanofabrication techniques, and passively probed in transmission measurements using a tunable red laser. Devices based on this material could serve as integrated optical elements as well as passive platforms for coupling to visible quantum emitters.
@article{arxiv.1111.3545,
title = {Integrated TiO2 resonators for visible photonics},
author = {Jennifer T. Choy and Jonathan D. B. Bradley and Parag B. Deotare and Ian B. Burgess and Christopher C. Evans and Eric Mazur and Marko Loncar},
journal= {arXiv preprint arXiv:1111.3545},
year = {2015}
}