Article,
Theory and experiment of transient two-wave mixing in Yb-doped single-frequency fiber amplifiers induced by frequency modulation
Affiliations
- [1] NKT Photon AS, Blokken 84, DK-3460 Birkerod, Denmark [NORA names: NKT Holding; Private Research; Denmark; Europe, EU; Nordic; OECD];
- [2] Tech Univ Denmark, Dept Elect & Photon Engn, Orsteds Plads Bldg 343, DK-2800 Lyngby, Denmark [NORA names: DTU Technical University of Denmark; University; Denmark; Europe, EU; Nordic; OECD];
- [3] Norlase ApS, Brydehusvej 13, DK-2750 Ballerup, Denmark [NORA names: Other Companies; Private Research; Denmark; Europe, EU; Nordic; OECD]
Abstract
This paper presents a theoretical and experimental characterization of an instability phenomenon observed in single -frequency fiber amplifiers when the frequency of the seed laser is modulated. The instability manifests itself as fluctuating elastic back -reflections that occur only when the frequency is decreasing with time. The theory is a generalization of a coupled -mode model developed for a single -frequency fiber amplifier back -seeded with a constant frequency shift relative to the main signal. It can explain most observed features of the experiments in a qualitative and semi -quantitative way. Open questions and directions for further developments are also discussed. (c) 2024 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement
