High-energy passively Q-switched 2 μm Tm^3+-doped double-clad fiber laser using graphene-oxide-deposited fiber taper

Abstract

We have demonstrated a high-energy Q-switched double-clad thulium-doped fiber laser (TDFL) using a graphene-oxide-deposited tapered fiber (GODTF) device as a saturable absorber operating at a wavelength of 2 μm for the first time. Because of the side-interaction of the graphene-oxide with the evanescent field on the taper waist, the GODTF devices have potential for offering high laser damage threshold. Using a 788 nm laser diode as the pump source, the TDFL generated stable single transverse mode Q-switched pulses with a single pulse energy of 6.71 μJ (corresponding to an average power of 302 mW) at a wavelength of 2032 nm. This is significantly higher than the highest pulse energy/average power from any rare-earth-doped fiber lasers employing a graphene or graphene-oxide based Q-switch so far. The demonstrated TDFL in this paper represents an encouraging step towards the practical applications of graphene or graphene-oxide based Q-switched 2 μm TDFLs.

Vector rectangular-shape laser based on reduced graphene oxide interacting with a long fiber taper

“…The waist diameter and the length of the taper is ~4 μm and 8 mm, respectively. Compared with the reported taper length [17][18][19], the 8 mm taper waist in our laser cavity provides enough interacting length between the rGO and the transmission light, guaranteeing excellent saturable absorption and high nonlinearity. As shown in Fig.…”

Black Phosphorus Q-Switched Large-Mode-Area Tm-Doped Fiber Laser

“…Passively Q-switched Tmdoped fiber lasers are favorable ways to generate high-energy pulses at 2 m, where two-dimension (2D) materials such as graphene, topological insulators (TIs), and transition metal dichalcogenides (TMDCs) are usually adopted as saturable absorbers (SAs) instead of commercial semiconductor saturable absorber mirror (SESAM) due to their low cost and easy fabrication [6][7][8][9][10][11][12][13].…”

Tunable passively Q-switched thulium-doped fiber laser operating at 1.9 μm using arrayed waveguide grating (AWG)

“…This is due to their emission being strongly absorbed by water [26], making them suitable to be applied in ophthalmic surgery. Q-switched TDFLs are also able to generate higher pulse energies at their output [27], making them important in the field of material processing and they are more efficient and are more simple as they do not require the subtle balancing of losses associated with mode-locking.…”