We demonstrate quasi-phase matched, triply-resonant sum frequency conversion in 10.6-um-diameter integrated gallium phosphide ring resonators. A small-signal, waveguide-to-waveguide power conversion efficiency of 8%/mW is measured for conversion from telecom (1536 nm) and near infrared (1117 nm) to visible (647 nm) wavelengths with an absolute power conversion efficiency of 6.3% measured at saturation pump power. For the complementary difference frequency generation process, a single photon conversion efficiency of 7.2%/mW from visible to telecom is projected for resonators with optimized coupling. Efficient conversion from visible to telecom will facilitate long-distance transmission of spin-entangled photons from solid-state emitters such as the diamond NV center, allowing long-distance entanglement for quantum networks.
@article{arxiv.2208.06764,
title = {Triply-Resonant Sum Frequency Conversion with Gallium Phosphide Ring Resonators},
author = {Alan D. Logan and Shivangi Shree and Srivatsa Chakravarthi and Nicholas Yama and Christian Pederson and Karine Hestroffer and Fariba Hatami and Kai-Mei C. Fu},
journal= {arXiv preprint arXiv:2208.06764},
year = {2023}
}