NONLINEAR OPTICAL PROPERTIES OF ZINC DOPED GERMANO-SILICATE GLASS OPTICAL FIBER

Abstract

Zinc doped germano-silicate glass optical fiber was developed by using the modified chemical vapor deposition and the drawing tower process. Absorption peaks of the germano-silicate glass optical fiber preform appeared at 240 nm and 330 nm were due to the incorporated Zn metal nano-particles (MNPs) and ZnO semiconductor nano-particles (SNPs), respectively and the average diameter of nano-particles (NPs) was estimated to be about 2 nm by transmission electron microscopy. However, the absorption peak of the zinc doped optical fiber due to ZnO SNPs was found to appear at 490 nm red-shifted from 330 nm can be explained by the increase in average size of ZnO SNPs in the fiber core due to growth or recrystallization of ZnO SNPs during the fiber drawing process about 2150°C. The nonlinear refractive index coefficient, n2, of the fiber was estimated to be 5.62 × 10-20 m2/W due to the stable dispersion of ZnO SNPs using the continuous-wave self-phase modulation method.