以973 nm半导体激光器(LD)为抽运源,高掺杂浓度Yb³⁺光纤为增益介质,构建了一套环形腔光纤激光器,通过调整腔内由普通光纤和偏振器件构成的偏振态滤波器,得到连续调谐宽度24 nm(1030-1054 nm)、激光阈值为49 mW的激光输出。通过对部分腔体光纤施加均匀应力的方法较大地扩展了激光器的调谐范围,实现了宽达57 nm(1021-1078 nm)的可调谐激光输出。与文献报道的基于偏振滤波原理的其他可调谐Yb³⁺光纤激光器相比,构建的激光器实现了更大范围的可调谐性。

A ring-cavity fiber laser using a 973-nm laser diode (LD) as pump source and a highly Yb³⁺-doped fiber as gain medium is built. A laser output with a continuously-tunable width of 24 nm (1030-1054 nm) and a threshold power of 49 mW is obtained by tuning the intra-cavity polarization filter,which is made of a common fiber and some polarization elements. Moreover,we significantly expand the tunable range to 57 nm (1021-1078 nm) by introducing uniform stress in a part of cavity fiber. Compared with other tunable Yb³⁺-doped fiber lasers on the principle of polarization filter,this laser system has realized a much wider tunable width.