全光纤同带泵浦宽带掺镱超荧光光纤光源的实验研究

采用自制的1018 nm光纤激光器做泵浦源，建立了全光纤同带泵浦的宽带掺镱超荧光光纤光源实验系统，首次利用同带泵浦对单程前向结构的超荧光产生进行了深入的实验研究。研究结果表明:基于同带泵浦的掺镱超荧光光源的斜率效率高达88%，半极大全宽度（Full Width at HalfMaximum，FWHM）最宽可以达到14.81 nm。掺镱光纤长度的改变，将影响超荧光光源的最大输出功率、斜率效率及中心波长，随着掺镱光纤长度的增加，最大输出功率和斜率效率下降，中心波长红移。固定光纤长度，改变泵浦功率，随着泵浦功率的增加，超荧光的最大功率和FWHM增加，光谱中心波长偏移很小。在掺镱光纤长度为5.7 m时，超荧光光源的最宽FWHM为14.81 nm，斜率效率在80.3%以上，输出功率的波动小于1%，没有驰豫振荡出现。

Experiment study on all-fiberized tandem pump broadband superfluorescent fiber source based on single stage Yb-doped fiber

With a homemade 1 018 nm fiber laser, an all-fiberized tandem pump broadband superfluorescent fiber source (SFS) based on single stage Yb-doped fiber was set up experimentally. It is the first time to experimently investigate the generation of forward superfluorescence by utilizing tandem pump in detail. Experimental results demonstrate the highest slope efficiency of 88% and the widest full width at half maximum (FWHM) of 14.81 nm for this all-fiberized tandem pump broadband SFS. The length of Ybdoped fiber would affect the maximum of output power, slope effiency and the central wavelength. With an increase in the length of Yb-doped fiber, the maximum of output power and slope effiency of the SFS are reduced. The central wavelength shifts towards the longer wavelength. With an increase of the pump power at a certain fiber length, the maximum of output power and slope effiency of the SFS increase. The central wavelength of superfluorescent spectrum has a slight shift. When 5.7 m Yb-doped fiber is employed as the active medium, the widest FWHM is 14.81 nm and the slope efficiency is above 80.3%. The fluctuation of the output power is less than 1% and no self pulsing or relaxation oscillation effect is observed.