2.8μm自相似锁模掺铒氟化物光纤激光器的数值研究

Numerical Investigation on Self-Similar Mode-Locked Er-Doped Fluoride Fiber Laser at 2.8μm

数值研究了中红外2.8μm波段基于可饱和吸收体(SA)锁模掺铒氟化物光纤激光器中自相似脉冲的产生及演化过程。结果表明:通过锗棒进行色散补偿使腔内净色散为0.020~0.048 ps2时,基于SA锁模的掺铒氟化物光纤激光器腔内脉冲可维持自相似演化;保持腔内净色散为0.03 ps2,可以获得抛物线形状最理想的脉冲,其脉冲宽度为19.7 ps、峰值功率为630 W、脉冲能量为12.4 nJ。为了进一步优化激光器的输出特性,研究了增益光纤的小信号增益、增益饱和能量以及SA的调制深度、饱和功率等参数对激光器脉冲输出特性的影响,为自相似锁模掺铒氟化物光纤激光器的设计提供了一定的参考。

In this paper,the generation and propagation of self-similar pulses in an Er-doped mode-locked fiber laser based on saturable absorber(SA)are numerically investigated.Research results indicate that by using a germanium rod to compensate the cavity dispersion,the intracavity pulse of an erbium-doped fluoride fiber laser based on SA mode-locking can support self-similar pulses evolution when the net dispersion of the cavity is in the range of 0.020-0.048 ps2.Keeping the net dispersion of the cavity with 0.03 ps2,ideal parabolic pulse with a pulse width of 19.7 ps,a peak power of 630 W,and a pulse energy of 12.4 nJ is obtained.To further optimize the output properties of the laser,the effects of small signal gain and gain saturated energy of the gain fiber,as well as the modulation depth and saturated power of the SA on the pulse output properties are studied in detail,which provides reference for the design of self-similar mode-locked Er-doped fluoride fiber lasers.