Owing to the limitation of the ray method in analyzing the field distribution and transmit power of optical waves in fibers we decide to apply waveguide theory for analyzing dcf with truncated inner cladding in an at tempt to find out the divergences of different types of dcf with truncated inner cladding in absorption efficiency in unit distance 由于射线法在分析光波在光纤中的场分布、传播功率等情况时有其局限性，因此，文章改用波动理论对缺陷型内包层双包层光纤进行分析，试图找出不同类型的缺陷型内包层双包层光纤单位距离内吸收效率的差异。
