Efficient operation of diode-pumped single-frequency thulium-doped fiber lasers near 2 micro m.
Efficient operation of diode-pumped single-frequency fiber lasers at wavelengths from 1740 to 2017 nm has been demonstrated by using a very short piece of newly developed single-mode active fiber, i.e., heavily thulium-doped germanate glass fiber. At 1893 nm, the single-frequency fiber laser has a pump threshold of 30 mW, a slope efficiency of 35%, and maximum output power of 50 mW with respect to the launched power of single-mode pump diodes at 805 nm. To the best of our knowledge, this is the highest lasing efficiency achieved in single-frequency fiber lasers operating near 2 micro m. Frequency noise of the single-frequency fiber laser at 1893 nm has been characterized and compared with that of single-frequency fiber lasers at 1 and 1.55 micro m.
Geng
Jihong
J
NP Photonics Incorporated, Tucson, AZ 85747, USA. geng@npphotonics.com
Wu
Jianfeng
J
Jiang
Shibin
S
Yu
Jirong
J