title: Two-colour high-speed asynchronous optical sampling based on offset-stabilized Yb:KYW and Ti:sapphire oscillators.
abstract: We present a high-speed asynchronous optical sampling system, based on two different Kerr-lens mode-locked lasers with a GHz repetition rate: An Yb:KYW oscillator and a Ti:sapphire oscillator are synchronized in a master-slave configuration at a repetition rate offset of a few kHz. This system enables two-colour pump-probe measurements with resulting noise floors below 10⁻⁶ at a data aquisition time of 5 seconds. The measured temporal resolution within the 1 ns time window is below 350 fs, including a timing jitter of less than 50 fs. The system is applied to investigate zone-folded coherent acoustic phonons in two different semiconductor superlattices in transmission geometry at a probe wavelength far below the bandgap of the superlattice constituents. The lifetime of the phonon modes with a zero wave vector and frequencies in the range from 100 GHz to 500 GHz are measured at room temperature and compared with previous work.
authors.forename: N
authors.initials: N
authors.lastname: Krauß
authors.forename: G
authors.initials: G
authors.lastname: Schäfer
authors.forename: J
authors.initials: J
authors.lastname: Flock
authors.forename: O
authors.initials: O
authors.lastname: Kliebisch
authors.forename: C
authors.initials: C
authors.lastname: Li
authors.forename: H G
authors.initials: HG
authors.lastname: Barros
authors.forename: D C
authors.initials: DC
authors.lastname: Heinecke
authors.forename: T
authors.initials: T
authors.lastname: Dekorsy