title: Subharmonic resonant optical excitation of confined acoustic modes in a free-standing semiconductor membrane at GHz frequencies with a high-repetition-rate femtosecond laser.
abstract: We propose subharmonic resonant optical excitation with femtosecond lasers as a new method for the characterization of phononic and nanomechanical systems in the gigahertz to terahertz frequency range. This method is applied for the investigation of confined acoustic modes in a free-standing semiconductor membrane. By tuning the repetition rate of a femtosecond laser through a subharmonic of a mechanical resonance we amplify the mechanical amplitude, directly measure the linewidth with megahertz resolution, infer the lifetime of the coherently excited vibrational states, accurately determine the system's quality factor, and determine the amplitude of the mechanical motion with femtometer resolution.
authors.affiliation: Department of Physics & Center for Applied Photonics, Universität Konstanz, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Bruchhausen
authors.forename: R
authors.initials: R
authors.lastname: Gebs
authors.forename: F
authors.initials: F
authors.lastname: Hudert
authors.forename: D
authors.initials: D
authors.lastname: Issenmann
authors.forename: G
authors.initials: G
authors.lastname: Klatt
authors.forename: A
authors.initials: A
authors.lastname: Bartels
authors.forename: O
authors.initials: O
authors.lastname: Schecker
authors.forename: R
authors.initials: R
authors.lastname: Waitz
authors.forename: A
authors.initials: A
authors.lastname: Erbe
authors.forename: E
authors.initials: E
authors.lastname: Scheer
authors.forename: J-R
authors.initials: JR
authors.lastname: Huntzinger
authors.forename: A
authors.initials: A
authors.lastname: Mlayah
authors.forename: T
authors.initials: T
authors.lastname: Dekorsy