Gain characteristics of ytterbium-doped SiO2–Al2O3–Y2O3 fibers

Ytterbium (Yb3+)-doped SiO2-Al2O3-Y2O3 fibers were fabricated by using a molten core method. An Yb3+ doped yttrium aluminium garnet crystal was used as the core material. The doping concentration of Yb3+ in the fabricated SiO2-Al2O3-Y2O3 fibers was measured to be similar to 3.26 wt%. The background loss of the above fibers was measured to be similar to 0.0085 dB cm(-1) at 1560 nm by using a cutback method. The gain characteristics of the Yb3+ doped fiber were measured by using a single mode fiber pigtailed 980 nm laser diode as the pump source, and an unit length gain of similar to 3.9 dB cm(-1) was obtained for a signal power of similar to 0.1 mu W at 1036 nm. Our result showed that the Yb3+ doped SiO2-Al2O3-Y2O3 fiber was a potential gain media for constructing narrow line-width fiber lasers.