Dual-Waveband Self-Pulsed Laser at 3 $mu$ m and 2.1 $mu$ m

摘要

We report dual-waveband self-pulsing at 3 and 2.1 mu m in a Ho-doped ZBLAN fiber laser, for the first time to our knowledge. In a linear cavity bi-directionally pumped at 1150 nm, stable 3- and 2.1-mu m self-pulsing in the kHz region with a ns similar to mu s scale was simultaneously achieved. Their behaviors depending on the pump power were similar to Q-switching and gain-switching, respectively. The preliminary experimental results indicated that the origin of the 3-mu m self-pulsing was probably the excited state re-absorption process I-5(7) -> I-5(6) and the 2-mu m self-pulsing should be induced by the 3-mu m self-pulsing by the way of gain-switching. At the maximum pump power of 8.72 W, the largest output power of 917.5 mW (3 mu m)/414.7 mW (2.1 mu m) and pulse energy of 5.87 mu J (3 mu m)/2.62 mu J (2.1 mu m) were gained. This demonstration provides an alternative way for 3- and 2.1-mu m dual-waveband short pulse generation in a simple scheme, which can find direct medical applications.