单轴晶体包层抛物型渐变光纤中基模功率分析

研究了以单轴晶体为包层，纤芯为各向同性非均匀材料光纤的功率传输特性.在纤芯满足弱渐变条件的假定下，按矢量场法进行了分析.针对基模讨论了包层的轴向与横向的介电常量比τ对光纤截面上功率分布的影响.结果表明,τ对低频情况影响显著，而对高频情况则影响很小.当此种结构的光纤用做单模光纤时，选用τ较大的包层材料有利于提高传输效率.

Analysis on Power Distribution of Parabolic Weakly-graded Index Optical Fiber with Uniaxial Crystal Cladding

The parabolic index optical fiber with uniaxial crystal cladding was studied by the vector-field method under the assumption of weakly-graded-index in the core. The power distribution in core and cladding for fundamental mode is analyzed. It is shown that the influence of parameter τ(the ratio of axial permittivity to transverse-permittivity in the cladding) to the power distribution for lower frequency is obvious,but it is negligible for higher frequency. Using the material of large τ to make the cladding is advantaged for the single-mode transmission in this kind of fiber.