主动调Q掺铥双包层光纤激光器

Actively Q-switched thulium-doped double-clad fiber laser

利用790 nm半导体激光器作为泵浦源、声光调制器作为Q开关,将4 m长掺铥双包层D型光纤作为增益光纤,在入纤功率9.17 W、调制频率50 kHz时,获得激光器最大输出功率为1.26 W.调制频率为30 kHz时,获得单脉冲能量40μJ的脉冲激光.激光器在30～50 kHz工作时可以获得稳定的脉冲输出.讨论了在阈值入纤功率附近形成1/2、1/3调制频率脉冲及在较大泵浦功率时形成多脉冲的原因.

An acoustic-optical Q-switched thulium-doped fiber laser pumped by a 790 nm diode laser was investigated in this experiment. A 4 m-long thulium-doped double cladding D-shaped fiber was adopted as the active fiber. When the launched pump power is 9.17 W, the maximum output power of 1.26 W at the repetition rate of 50 kHz was obtained while the maximum single pulse energy was 40μL at the repetition rates of 30 kHz. Stable pulses could be achieved at the repetition rates from 30 kHz to 50 kHz. The cause of the pulses with 1/2 and 1/3 modulation frequency generated near the threshold launched pump power was analyzed. In addition, the reason for multi pulses at high pump power was also examined.