Spectral Dynamics of Actively Q-Switched Erbium-Doped Fiber Lasers

• Published in: IEEE photonics technology letters 2017-04, Vol.29 (8), p.683-686
• Main Authors: Minguela-Gallardo, J. A., Barmenkov, Y. O., Kir'yanov, A. V., Villegas-Garcia, I. L., Beltran-Perez, G., Kuzin, E. A.
• Format: Article
• Language: English
• Subjects: Cavity resonators; dynamics; erbium-doped fiber laser; Erbium-doped fiber lasers; Geometry; Optical pulses; Optical reflection; optical spectrum; Optical variables measurement; Q-switch; supercontinuum generation
• ISSN: 1041-1135; 1941-0174
• DOI: 10.1109/LPT.2017.2677743

We report the spectral dynamics of actively Q-switched erbium-doped fiber lasers implemented in two common laser configurations: linear Fabry-Pérot cavity with a pair of fiber Bragg gratings as reflectors and one-directional ring cavity without spectrally selective elements. In both geometries, the spectral width of sub-pulses, forming a Q-switch pulse, depends on the sub-pulse number, the spectrum of the most powerful sub-pulse is much broader than those of the rest, less powerful, ones. In the case of the ring laser, the optical spectra of sub-pulses shift to the Stokes side with increasing a sub-pulse's number. Possible reasons for such laser spectral dynamics are discussed. We also reveal the details of supercontinuum generation in a 100-m-long telecom fiber when such Q-switch pulses are employed as pump.