title: Broadband infrared spectroscopy using optical parametric oscillation in a radially-poled whispering gallery resonator.
abstract: We demonstrate optical parametric oscillation in a millimeter-sized whispering gallery resonator suitable for broadband infrared spectroscopy. This nonlinear-optical process is quasi-phase-matched using a radial domain pattern with 30 µm period length, inscribed by calligraphic poling. The output wavelengths are selected in a controlled way over hundreds of nanometers. We achieve this by increasing the temperature of the resonator in steps such that the azimuthal mode number of the pump wave rises by one. As a proof-of-principle experiment, we measure a characteristic resonance of polystyrene in the spectral range of 2.25 - 2.45 µm.
authors.forename: Sarah-Katharina
authors.initials: SK
authors.lastname: Meisenheimer
authors.forename: Josef Urban
authors.initials: JU
authors.lastname: Fürst
authors.forename: Christoph
authors.initials: C
authors.lastname: Werner
authors.forename: Tobias
authors.initials: T
authors.lastname: Beckmann
authors.forename: Karsten
authors.initials: K
authors.lastname: Buse
authors.forename: Ingo
authors.initials: I
authors.lastname: Breunig