Polarisation dependence in thermally poled twin-hole silica fibre

Abstract

A hypothesis is presented based on the distribution of the frozen-in electric field around the core that qualitatively explains the smaller than expected polarisation dependence observed in thermally poled twin-hole silica fibre. The polarisation dependent 3:1 ratio of the local electro-optic response that is predicted by the charge separation model will be averaged over the region spanned by the polarisation modes. If the electric field is non-uniform, or more specifically non parallel, then on average the polarisation dependence will be reduced. In this paper experimental results and a qualitative analysis are presented.