Supercontinuum source directly from noise-like pulse emission in a Tm-doped all-fiber laser with nonlinear polarization rotation

Abstract

Supercontinuum (SC) generation directly from noise-like pulse (NLP) emission is demonstrated in a mode-locked thulium-doped all-fiber laser with nonlinear polarization rotation. The laser supports NLP emission at a repetition rate of 812.79 kHz, producing optical pulses of 2 ns pulse duration and 400 nm of optical bandwidth, which expands from 1800 nm to 2200 nm at floor level and covers the entire thulium band. The SC source presents a high dynamic range, higher than 50 dB, a high degree of spectral flatness, without significant spectral variations or pump remnants, and an output average power of 20.25 mW. Moreover, our proposal avoids the inclusion of external components and devices, thus preserving the robustness and simplicity in a single all-fiber system.