Fig. 1. Fabricated silicate core glass and cladding glass

Fig. 2. Absorption cross section of Tm-doped silicate glass (Inset: the tested Tm-doped silicate glass)

Fig. 3. Emission cross section of Tm-doped silicate glass

Fig. 4. ³F₄ energy level fluorescence decay curve of Tm-doped silicate glass

Fig. 5. (a) End face of Tm-doped silicate glass fiber and (b) the fusion splice of silica fiber and Tm-doped silicate fiber

Fig. 6. Experimental scheme of Tm-doped fiber DBR laser

Fig. 7. Output power of the laser versus pump power with different active fiber lengths

Fig. 8. Spectrum of the laser at maximum output power with 2 cm active fiber (Inset: laser spectrum measured with a resolution of 0.05 nm)