摘要
根据非线性薛定谔方程建立了基于可饱和吸收体被动锁模掺Er^(3+)氟化物光纤激光器的理论模型,研究了中红外超短脉冲在掺Er^(3+)氟化物光纤激光器中形成的物理机制,数值模拟了被动锁模掺Er^(3+)氟化物光纤激光器中中红外超短脉冲的演化过程,重点分析了掺Er^(3+)增益光纤长度,可饱和吸收体不饱和损耗对被动锁模掺Er^(3+)氟化物光纤激光器产生中红外超短脉冲的影响,并给出了参数设置范围。研究发现:当小信号增益系数、可饱和吸收体不饱和损耗、腔内净色散量为一定值,掺Er^(3+)氟化物光纤长度在一定范围时,才会出现稳定的锁模脉冲,且随着掺Er^(3+)氟化物光纤长度增加脉冲宽度变窄、光谱变宽、峰值功率增高;当掺Er^(3+)氟化物光纤长度、腔内净色散量、小信号增益系数为一定值时,可饱和吸收体不饱和损耗在一定的范围时可以得到稳定的锁模脉冲,且随着可饱和吸收体不饱和损耗的增加脉冲宽度变窄,光谱先变宽后变窄变化范围不大,峰值功率增加。
Based on the Nonlinear Schr/Sdinger Equation（NLSE）, the theoretical model of psssively mode- locked Er3＋-doped fluorid fiber laser using a saturable absorber was set up, by which the mechanism of generating mid-infrared ultrashort pulse in the fiber laser was investigated. The numerical simulation focused on the evolution process of the mid-infrared ultrashort pulse in fluorine fiber laser. The impact of the Er3＋： fluorine gain fiber length and the saturable absorber unsaturated loss on the generation of mode-locked pulse was analyzed in detail, and the reasonable parameter range was determined. It is found that for a given set of small-signal gain, unsaturated loss, and net intracavity dispersion, the stable mode-locked pulses are achieved by tuning the Er3＋： fluorine gain fiber length within a certain range. With increasing the Er3＋： fluorine gain fiber length, the output pulse duration decreased gradually, while the increase of the spectrum width （FWHM） and the peak power are observed. Meanwhile, for a given set of Er3＋： fluorine gain fiber length, net intracavity dispersion and small-signal gain, the stable mode- locked pulses are also obtained by adjusting the saturable absorber unsaturated loss within a certain range. With the increase of the saturable absorber unsaturated loss, the output pulse duration decreases gradually, however spectral width broadens and then narrows, and peak power increases gradually.
出处
《红外与激光工程》
EI
CSCD
北大核心
2016年第11期67-72,共6页
Infrared and Laser Engineering
