Low-loss nano- and micro-photonic platforms provide strong optical confinement and as a result enhance the effective material nonlinearity by several orders of magnitude, making them appealing candidates for quantum nonlinear photonics. One such platform is based on high-Q crystalline whispering-gallery-mode (WGM) microresonators, which can provide for highly efficient three-wave mixing, where even a single photon has a strong effect. We present experimental progress on the fabrication of small microresonators (R⪅100 μm) with Q-factors ≥ 10⁶ that are capable of supporting such strong coupling. We also demonstrate direct imaging of the spatial profiles of the WGMs, which is useful for identifying the phase-matched resonances of three-wave-mixing processes. Additionally, we present theoretical modeling of the cavity dynamics which suggests that single-photon-driven nonlinear processes are feasible in these crystalline microresonators. This crystalline WGM microresonator platform, therefore, can enable deterministic generation of non-classical light, including entangling gates for quantum information processing.

Date Published: 18 September 2018
PDF: 9 pages
Proc. SPIE 10771, Quantum Communications and Quantum Imaging XVI, 1077108 (18 September 2018); doi: 10.1117/12.2317833

Published in SPIE Proceedings Vol. 10771:
Quantum Communications and Quantum Imaging XVI
Ronald E. Meyers; Yanhua Shih; Keith S. Deacon, Editor(s)