Broadband amplification and highly efficient lasing in erbium-doped tellurite microstructured fibers

We report broadband amplification and highly efficient lasing in erbium-doped tellurite microstructured fibers. A broad positive net gain bandwidth of 113 nm (1524-1637 nm) is obtained in a 17 cm long erbium-doped tellurite microstructured fiber upon a pump power of 94 mW at 1480 nm. An all-fiber lasing at 1561 nm with maximum unsaturated power of 140 mW and slope efficiency of 53.7% is achieved from the fiber by employing a linear cavity. In addition, the influence of the fiber length on amplification and lasing is investigated and laser oscillation at 1535 nm is realized in a 4.3 cm long fiber.