基于结模型的极化石英光纤内建电场分析

用多载流子模型分析了D型石英光纤的热极化过程及耗尽层的形成,分析了氢离子注入及钠离子耗尽层的形成.并把正负电荷的交界处类比为pn结,分别计算了所形成的内建电场大小.最终得出极化完成后石英光纤的二阶非线性效应主要由钠离子的耗尽形成,计算出的内建电场大小约为108 V/m,由此算出的二阶非线性系数的数值在0.10～0.60 pm/V,和实验报道数值符合较好.

Analysis of Built-in Field in Poled Silica Fiber Using Junction Model

The thermal poling process and the formation of depletion layer in D-type silica fiber were analyzed by multi-carriers model. Hydrogen ion injection and the formation of Na ion depletion layer was given. We draw an analogy between pn junction and the interface of the positive and negative charges, and the built-in electric field was calculated. It is conculded that the second order nonlinear effect appeared in the polarization silica fiber is determined mainly by the exhaustion of Na ion. The built-in electric field is about 108V/m and based on which, the calculated second-order nonlinearity value is within 0.1~0.6pm/V, which is consistent well with the experimental data.