title: 2 μm semiconductor disk laser with a heterodyne linewidth below 10 kHz.
abstract: We demonstrate a 2 μm semiconductor disk laser emitting in a single longitudinal mode with a linewidth in the <10 kHz range. A heterodyne detection scheme was used for precise linewidth measurements. In these experiments, the output beams of two identical laser cavities were superposed in order to generate a beat note signal on a photodiode. In the absence of active frequency stabilization, a linewidth of 45 kHz was measured at an output power of 100 mW. When using a frequency stabilization consisting of a feedback loop with a Fabry-Perot interferometer as wavelength reference, the linewidth could be further reduced to 9 kHz.
authors.affiliation: Fraunhofer-Institut für Angewandte Festkörperphysik, Freiburg, Germany.
authors.forename: Benno
authors.initials: B
authors.lastname: Rösener
authors.forename: Sebastian
authors.initials: S
authors.lastname: Kaspar
authors.forename: Marcel
authors.initials: M
authors.lastname: Rattunde
authors.forename: Tino
authors.initials: T
authors.lastname: Töpper
authors.forename: Christian
authors.initials: C
authors.lastname: Manz
authors.forename: Klaus
authors.initials: K
authors.lastname: Köhler
authors.forename: Oliver
authors.initials: O
authors.lastname: Ambacher
authors.forename: Joachim
authors.initials: J
authors.lastname: Wagner