Proceedings Article | 1 December 2017
Proc. SPIE. 10603, Photonics, Devices, and Systems VII
KEYWORDS: Signal to noise ratio, Ultrafast phenomena, Resonators, Dispersion, Mode locking, Solitons, Fiber lasers, Laser resonators, Picosecond phenomena, Pulsed laser operation
Today ultrashort pulse (USP) fiber lasers are in great demand in a frequency metrology field, THz pulse spectroscopy,
optical communication, quantum optics application, etc. Therefore mode-locked (ML) fiber lasers have been extensively
investigated over the last decade due the number of scientific, medical and industrial applications. It should be noted,
that USP fiber lasers can be treated as an ideal platform to expand future applications due to the complex ML nonlinear
dynamics in a laser resonator. Up to now a series of novel ML regimes have been investigated e.g. self-similar pulses,
noise-like pulses, multi-bound solitons and soliton rain generation. Recently, we have used a highly nonlinear
germanosilicate fiber (with germanium oxides concentration in the core ~ 50 mol. %) inside the resonator for more
reliable and robust launching of passive mode-locking based on the nonlinear polarization evolution effect in fibers. In
this work we have measured promising and stable ML regimes such as stretched pulses, soliton rain and multi-bound
solitons formed in a highly-nonlinear ring laser and obtained by intracavity group velocity dispersion (GVD) variation in
slightly negative region. As a result, we have obtained the low noise ultrashort pulse generation with duration < 250 fs
(more than 20 bound pulses when obtained multi-bound soliton generation with intertemporal width ~ 5 ps) at a
repetition rate ~ 11.3 MHz (with signal-to-noise ratio at fundamental frequency > 59 dB) and relative intensity noise
<-101 dBc / Hz.
