Switchable dissipative soliton resonance and noise like pulses regimes in a mode-locked double-clad thulium doped fiber laser

We report an experimental study of switchable rectangular pulses generation in a passively mode-locked double-clad thulium-doped fiber laser operating in the anomalous dispersion regime. A fiber loop mirror and a polarization imbalanced nonlinear optical loop mirror (NOLM) forms the linear cavity. The loop in the NOLM includes a quarter-wave retarder, which allows switching between two regimes of rectangular pulse generation. The laser generates rectangular noise-like pulses (NLPs) or dissipative soliton resonance (DSR) pulses with 1.18 MHz repetition rate at similar to 1990 nm. At the maximum pump power of 10 W, rectangular pulses with energy of up to 540 nJ in DSR operation and 482 nJ in NLP operation were obtained with output average power of 640 mW and 571 mW, respectively.

Automated summary

In this experimental study, switchable rectangular pulses were generated in a passively mode-locked double-clad thulium-doped fiber laser operating in the anomalous dispersion regime. The laser utilizes a fiber loop mirror and a polarization imbalanced nonlinear optical loop mirror (NOLM) to form a linear cavity, with the loop in the NOLM allowing switching between two regimes of rectangular pulse generation. The laser is capable of generating rectangular noise-like pulses (NLPs) or dissipative soliton resonance (DSR) pulses with 1.18 MHz repetition rate at around 1990 nm.