title: Highly tunable low-threshold optical parametric oscillation in radially poled whispering gallery resonators.
abstract: Whispering-gallery resonators (WGR's), based on total internal reflection, possess high quality factors in a broad spectral range. Thus, nonlinear-optical processes in such cavities are ideally suited for the generation of broadband or tunable electromagnetic radiation. Experimentally and theoretically, we investigate the tunability of optical parametric oscillation in a radially structured WGR made of lithium niobate. With a 1.04  μm pump wave, the signal and idler waves are tuned from 1.78 to 2.5  μm--including the point of degeneracy--by varying the temperature between 20 and 62 °C. A weak off centering of the radial domain structure extends considerably the tuning capabilities. The oscillation threshold lies in the mW-power range.
authors.affiliation: Institute of Physics, University of Bonn, Wegelerstraße 8, 53115 Bonn, Germany. beckmann@uni-bonn.de
authors.forename: T
authors.initials: T
authors.lastname: Beckmann
authors.forename: H
authors.initials: H
authors.lastname: Linnenbank
authors.forename: H
authors.initials: H
authors.lastname: Steigerwald
authors.forename: B
authors.initials: B
authors.lastname: Sturman
authors.forename: D
authors.initials: D
authors.lastname: Haertle
authors.forename: K
authors.initials: K
authors.lastname: Buse
authors.forename: I
authors.initials: I
authors.lastname: Breunig