Ytterbium-sensitized thulium-doped f iber laser with a single-mode output operating at 1 900-nm region

Abstract

A single-mode laser is demonstrated using a newly developed double-clad thulium-ytterbium-doped fiber (TYDF) in a linear cavity formed by two fiber Bragg gratings (FBGs). The YTF used is drawn from a D-shape preform fabricated using the modified chemical vapor deposition and solution doping technique. The laser is operated at 1 901.6 nm via the transition of thulium ions from 3 F4 to 3 H6 with the assistance of ytterbium to thulium ion energy transfer. The efficiencies of the laser are 0.71% and 0.75% at 927and 905-nm multimode pumping, respectively. The thresholds of the launched pump power for 927-and 905-nm pumping are 1 314 and 1 458 mW, respectively. A 7-mW output is obtained at a 905-nm pump power of 2 400 mW. OCIS codes: 140.3510, 060.3510.

Low-phonon PbF2:Tm3+-doped crystal for 1.9µm lasing

“…Generally, Tm 3+ -doped active media can be used for direct diode pumping at 785 nm and the quantum efficiency can reach 2 because two Tm ions are raised to the upper laser level by one absorbed pump photon [9]. However, as a quasithree level system, the laser emission near 1.9 µm is difficult to obtain because of the reabsorption effect of the Tm ions.…”

“…However, as a quasithree level system, the laser emission near 1.9 µm is difficult to obtain because of the reabsorption effect of the Tm ions. Although many Tm 3+ -doped crystals (YAG, YAP, YLF and LLF) [10][11][12][13][14][15][16][17][18][19][20] were studied in the past (shown in table 1) and several of them have shown good laser performance, only the Tm:YLF crystal [9] achieves efficient laser operation with a center wavelength near 1.9 µm. Compared with oxide crystals, fluoride crystals are interesting because of their lowphonon energy reducing non-radiative relaxation and making them particularly suitable for infrared (IR) transitions, lower refractive index limiting non-linear effects, high transparency within a wide wavelength region from the vacuum ultraviolet to the IR and longer fluorescence lifetime for improving energy storage [21][22][23][24].…”