Dual-Operation Regime Thulium-Doped Fiber Laser and Its Applications in Cascaded Raman Light and Supercontinuum Generation

Abstract

We report on a passively mode-locked thulium-doped fiber laser (TDFL) with dual operation regimes and applications in cascaded Raman light and supercontinuum generation. The mode-locking is initiated by using a semiconductor saturable absorber mirror (SESAM) and can operate at both fundamental mode-locking and noise-like twin-pulse regimes. Output power can be scaled up through two-stage amplifications, and then was further fed into a segment of ultrahigh numerical aperture (NA) single-mode fiber with a length of ~30 m. At the fundamental mode-locking regime, two orders of stokes lights can be generated, centered at 2.13 and 2.35 μm, respectively, with a maximum total power of 3.75 W. At the noise-like twin-pulse regime, a near-infrared supercontinuum from 1.93 to 2.46 μm was generated with a maximum average output power of 2.5 W. It is, to the best of our knowledge, the first demonstration of both cascaded Raman light and supercontinuum generation with the same system.

Keywords

• Thulium-doped fiber lasers
• supercontinuum generation
• Raman
• laser amplifiers