title: Naturally phase-matched second-harmonic generation in a whispering-gallery-mode resonator.
abstract: We demonstrate for the first time natural phase matching for optical frequency doubling in a high-Q whispering-gallery-mode resonator made of lithium niobate. A conversion efficiency of 9% is achieved at 30 microW in-coupled continuous wave pump power. The observed saturation pump power of 3.2 mW is almost 2 orders of magnitude lower than the state-of-the-art value. This suggests an application of our frequency doubler as a source of nonclassical light requiring only a low-power pump, which easily can be quantum noise limited. Our theoretical analysis of the three-wave mixing in a whispering-gallery-mode resonator provides the relative conversion efficiencies for frequency doubling in various modes.
authors.affiliation: Max Planck Institute for the Science of Light, Erlangen, Germany.
authors.forename: J U
authors.initials: JU
authors.lastname: Fürst
authors.forename: D V
authors.initials: DV
authors.lastname: Strekalov
authors.forename: D
authors.initials: D
authors.lastname: Elser
authors.forename: M
authors.initials: M
authors.lastname: Lassen
authors.forename: U L
authors.initials: UL
authors.lastname: Andersen
authors.forename: C
authors.initials: C
authors.lastname: Marquardt
authors.forename: G
authors.initials: G
authors.lastname: Leuchs