采用MCVD方法研发了掺镱双包层光纤,并对其结构特性、荧光特性和激光特性进行了测试和研究.其D形内包层尺寸为400/450μm,数值孔径为0.36,纤芯直径约为16μm,数值孔径约为0.18.荧光谱线的范围为1 000～1 140 nm,1 030 nm处的峰宽大于50 nm.采用大功率激光二极管单端泵浦6 m长的双包层光纤,在泵浦入纤功率为61 W时,获得了32 W的激光输出,斜率效率为64%.该光纤在高功率处未发现饱和现象,通过优化光纤参数与泵浦方式还可以提高转化效率和输出功率.试验表明该光纤可以取代进口光纤用作高功率激光器件。

The double clad fiber made in China was fabricated by the modified chemical-vapor deposition (MCVD) technique. The geometric, fluorescence, and laser characters of the fiber were measured. The fiber has a 16 μm diameter Yb-doped core with a numerical aperture (N_A) of 0.18,and the inner cladding has a 400/450 μm diameter for the longer/shorter axis with a N_A of 0.36. The fluorescence spectrum ranged from 1 000~1 140 nm, and the spectrum width at 1 030 nm is greater than 50 nm.When one end of the fiber was pumped by a high-power laser diode with the launched power of 61 W, 32 W laser output was obtained with the slope efficiency of 64%. There is no evidence of saturation at high pump powers, so the output power can be further improved by optimizing the parameters.