梯度掺稀土光纤的制备工艺研究

Study on the preparation of graded rare earth doped fiber

为了提高掺稀土光纤的纵向温度分布均匀性和受激布里渊散射效应的阈值功率,研究了光纤纵向距离上稀土离子掺杂浓度呈梯度分布的掺稀土光纤的制备方法。分析了制备梯度掺稀土光纤预制棒的工艺要求与光纤几何尺寸的关系。基于离子液相掺杂方法,采用疏松层分区多次浸泡技术,在光纤预制棒中仅为28.0 mm的长度区间内,镱离子实现了含四个“台阶”的梯度掺杂。将梯度掺杂预制棒拉制成掺稀土光纤后,对长度为11.2 m的梯度掺杂段光纤的976 nm波长处包层吸收系数进行了测试,高掺杂浓度区的吸收系数达到了低掺杂浓度区的2.57倍。

In order to improve the longitudinal uniformity of temperature distribution and the threshold power of stimulated Brillouin scattering effect of rare earth doped fiber,the preparation method of rare earth doped fiber with gradient distribution of rare earth ion doping concentration along the longitudinal distance of the fiber is studied.The relationship between the technological requirements of the preparation of rare earth doped graded preform and the geometrical size of the optical fiber is analyzed.Based on the method of ionic liquid phase doping,using the technology of porous layer division and multiple immersion,ytterbium ion achieved gradient doping with four steps in the length range of 28.0 mm in the fiber preform.The 976 nm cladding absorption coefficient of 11.2 m graded doped fiber is measured after the graded doped preform is drawn into the rare earth doped fiber.The absorption coefficient in the high doping concentration region is 2.57 times of that in the low doping concentration region.