Mayer Aline S, Grosinger Wilfrid, Fellinger Jakob, Winkler Georg, Perner Lukas W, Droste Stefan, Salman Sarper H, Li Chen, Heyl Christoph M, Hartl Ingmar, Heckl Oliver H
Opt Express. 2020 Jun 22;28(13):18946-18968. doi: 10.1364/OE.394543.
We present a flexible all-polarization-maintaining (PM) mode-locked ytterbium (Yb):fiber laser based on a nonlinear amplifying loop mirror (NALM). In addition to providing detailed design considerations, we discuss the different operation regimes accessible by this versatile laser architecture and experimentally analyze five representative mode-locking states. These five states were obtained in a 78-MHz configuration at different intracavity group delay dispersion (GDD) values ranging from anomalous (-0.035 ps) to normal (+0.015 ps). We put a particular focus on the characterization of the intensity noise as well as the free-running linewidth of the carrier-envelope-offset (CEO) frequency as a function of the different operation regimes. We observe that operation points far from the spontaneous emission peak of Yb (∼1030 nm) and close to zero intracavity dispersion can be found, where the influence of pump noise is strongly suppressed. For such an operation point, we show that a CEO linewidth of less than 10-kHz at 1 s integration can be obtained without any active stabilization.
