【作者】 王少奇； 邓颖； 李超； 王方； 张永亮； 康民强； 薛海涛； 罗韵； 粟敬钦； 胡东霞； 郑奎兴； 朱启华；

【Author】 Wang Shaoqi;Deng Ying;Li Chao;Wang Fang;Zhang Yongliang;Kang Minqiang;Xue Haitao;Luo Yun;Su Jingqin;Hu Dongxia;Zheng Kuixing;Zhu Qihua;Research Center of Laser Fusion,China Academy of Engineering Physics;Science and Technology on Plasma Physics Laboratory;collaborative Innovation Center of IFSA (CICIFSA),Shanghai JiaoTong University;Graduate School of China Academy of Engineering Physics;

【机构】 中国工程物理研究院激光聚变研究中心； 等离子体物理重点实验室； IFSA协同创新中心上海交通大学； 中国工程物理研究院研究生院；

【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Er³⁺氟化物光纤激光器的理论模型,在此基础上研究了中红外超短脉冲在掺Er³⁺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Er³⁺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Er³⁺增益光纤长度,可饱和吸收体不饱和损耗对被动锁模掺Er³⁺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Er³⁺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Er³⁺氟化物光纤长度增加脉冲宽度变窄,光谱变宽,峰值功率升高;当掺Er³⁺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。更多还原

【Abstract】 Based on the nonlinear Schr?dinger equation（NLSE）, the theoretical model of psssively modelocked Er³⁺-doped fluorid fiber laser using a saturable absorber is set up, by which the mechanism of generating mid-infrared ultrashort pulse in the fiber laser is investigated. The numerical simulation focuses 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 is analyzed in detail, and the reasonable parameter range is determined. It’s 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 decreases 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 increase gradually.更多还原