Our work on "Frequency doubling from a Whispering Gallery Mode Cavity with Ultra-High Q" has been published in Physical Review Letters
We study non-critical phase matching for optical frequency doubling in whispering gallery mode resonators and demonstrate this process in a high-Q resonator made from Lithium Niobate. A conversion effciency of 9% is achieved at 30 microwatt in-coupled CW pump power. The observed saturation pump power of 3.2 mW is almost two orders of magnitude lower than the former state-of-the-art.This suggests an important application of the demonstrated frequency doubler as a source of non-classical light pumped by a low-power, shot-noise (or even sub-shot noise) pump.