提出并演示了一种基于声光调制器(AOM)主动调Q的环形腔双包层光纤激光器获得窄线宽、窄脉宽和高重复频率激光脉冲的方法。通过在腔内采用以双包层增益光纤作为输入尾纤的泵浦剥离器来缩短腔长,可以降低增益光纤正向放大自发辐射(ASE)的反射,抑制其ASE的增益自饱和效应,使腔内有效增益增大,窄线宽调Q脉冲可在环形腔中快速建立,从而不仅可使调Q脉冲脉宽变窄,还允许其重复频率大幅提升。在7 W泵浦功率下,所提出的调Q光纤激光器获得了线宽和脉宽分别窄至0.16 nm和10.4 ns、重复频率高达150 kHz的调Q激光脉冲。

This paper proposes and demonstrates a method to produce narrow-linewidth, narrow-pulse-width, and high-repetition-rate pulses with actively Q-switched ring-cavity all-fiber lasers based on acoustic-optic modulators. We use a double-clad gain fiber as the cladding power stripper's input fiber in the ring cavity to shorten the cavity length and reduce reflections from the forward amplified spontaneous emission (ASE) at the output end of the gain fiber, which can efficiently suppress the ASE gain self-saturation so that the effective cavity gain can be enhanced. The narrow-linewidth Q-switched laser pulse can be established quickly, providing a narrow pulse width and high repetition rate for the pulses. Our experimental results demonstrate that the laser can produce 150-kHz Q-switched laser pulses with a narrow linewidth and pulse width of 0.16 nm and 10.4 ns, respectively, at a pump power of 7 W.