title: First investigation of the noise and modulation properties of the carrier-envelope offset in a modelocked semiconductor laser.
abstract: We present the first characterization of the noise properties and modulation response of the carrier-envelope offset (CEO) frequency in a semiconductor modelocked laser. The CEO beat of an optically-pumped vertical external-cavity surface-emitting laser (VECSEL) at 1030 nm was characterized without standard f-to-2f interferometry. Instead, we used an appropriate combination of signals obtained from the modelocked oscillator and an auxiliary continuous-wave laser to extract information about the CEO signal. The estimated linewidth of the free-running CEO beat is approximately 1.5 MHz at 1-s observation time, and the feedback bandwidth to enable a tight CEO phase lock to be achieved in a future stabilization loop is in the order of 300 kHz. We also characterized the amplitude and phase of the pump current to CEO-frequency transfer function, which showed a 3-dB bandwidth of ∼300  kHz for the CEO frequency modulation. This fulfills the estimated required bandwidth and indicates that the first self-referenced phase-stabilization of a modelocked semiconductor laser should be feasible in the near future.
authors.forename: Pierre
authors.initials: P
authors.lastname: Brochard
authors.forename: Nayara
authors.initials: N
authors.lastname: Jornod
authors.forename: Stéphane
authors.initials: S
authors.lastname: Schilt
authors.forename: Valentin J
authors.initials: VJ
authors.lastname: Wittwer
authors.forename: Sargis
authors.initials: S
authors.lastname: Hakobyan
authors.forename: Dominik
authors.initials: D
authors.lastname: Waldburger
authors.forename: Sandro M
authors.initials: SM
authors.lastname: Link
authors.forename: Cesare G E
authors.initials: CG
authors.lastname: Alfieri
authors.forename: Matthias
authors.initials: M
authors.lastname: Golling
authors.forename: Laurent
authors.initials: L
authors.lastname: Devenoges
authors.forename: Jacques
authors.initials: J
authors.lastname: Morel
authors.forename: Ursula
authors.initials: U
authors.lastname: Keller
authors.forename: Thomas
authors.initials: T
authors.lastname: Südmeyer