Extremely compact high power erbium-ytterbium codoped phosphate glass fiber lasers

Extremely compact high-power fiber lasers operating at eye-safe telecom wavelength of 1.5 mum have been achieved by systematic experimental studies. Heavily Er3+-Yb3+-codoped phosphate glasses have been chosen as the host glass for our fibers and 1.5 mum lasers have been realized when pumped with 975 nm laser diodes.; The first short-length cladding-pumped fiber laser with watt-level CW output power has been demonstrated by an 11-cm-long doped step-index phosphate fiber. Without active cooling, 1.5 W output power at 1535 nm has been obtained.; Thermoelectric cooler has been used for heavily doped phosphate step-index fibers. A dual-end-pumped actively cooled fiber laser has generated more than 11 W CW output power at 1535 nm from an 11.9 cm long active fiber. A fully 3-dimensional thermal analysis has been performed to calculate the internal temperature distribution of the shortlength fiber laser and the simulated results have been experimentally verified.; Phosphate glass microstructured optical fibers (MOFs) with large active cores have been fabricated. The first demonstrated short phosphate MOF laser has generated >3 W single-mode CW output power from an 11-cm-long fiber. The impacts of depressed-core-index and annealing upon MOF's modal property have been systematically investigated. Extremely compact high-power fiber laser is demonstrated by a heavily doped MOF laser and >4.5 W single-mode CW output power is delivered from a 3.5 cm long fiber. Finally, a high-power single-frequency fiber laser is realized by splicing a FBG with a 3.8 cm long MOF, which achieves >2 W single-frequency output power.