分析了W 型单模单偏振光纤中 ,椭圆内包层硼掺杂量与单模单偏振带宽的关系 ,得出了长W 型单模单偏振光纤的带宽与内包层硼掺杂量的大小无关 ,它只由光纤几何结构以及内包层折射率深度确定 ,而对于短W 型单模单偏振光纤 ,硼掺杂量的增加可以增大截止基模能量损耗 ,从而适度提高其消光比和有效带宽。 The relationship between the amount of boron doping and the single mode single polarization bandwidth in the W single mode single polarization fiber is analyzed. It is found that the bandwidth of the long W single mode single polarization fiber is not related to the boron content of the inner cladding , Which is only determined by the fiber geometry and the refractive index depth of the inner cladding. For the short W single mode single polarization fiber, the increase of the boron doping amount can increase the energy loss of the cutoff fundamental mode, so as to moderately increase its extinction ratio and effective bandwidth .