title: Instantaneous lineshape analysis of Fourier domain mode-locked lasers.
abstract: We present a theoretical and experimental analysis of the instantaneous lineshape of Fourier domain mode-locked (FDML) lasers, yielding good agreement. The simulations are performed employing a recently introduced model for FDML operation. Linewidths around 10 GHz are found, which is significantly below the sweep filter bandwidth. The effect of detuning between the sweep filter drive frequency and cavity roundtrip time is studied revealing features that cannot be resolved in the experiment, and shifting of the instantaneous power spectrum against the sweep filter center frequency is analyzed. We show that, in contrast to most other semiconductor based lasers, the instantaneous linewidth is governed neither by external noise sources nor by amplified spontaneous emission, but it is directly determined by the complex FDML dynamics.
authors.affiliation: Institute for Nanoelectronics, Technische Universität München, Munich, Germany. todor@tum.de
authors.forename: Sebastian
authors.initials: S
authors.lastname: Todor
authors.forename: Benjamin
authors.initials: B
authors.lastname: Biedermann
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Wieser
authors.forename: Robert
authors.initials: R
authors.lastname: Huber
authors.forename: Christian
authors.initials: C
authors.lastname: Jirauschek
mesh_terms: D003198:Computer Simulation; D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005583:Fourier Analysis; D007834:Lasers; D008962:Models, Theoretical