Fabrication of silicon based glass fibres for optical communication

Abstract

Silicon based glass fibres are fabricated by conventional fibre drawing process. First, preform fabrication is carried out by means of conventional MCVD technique by using various dopants such as SiCl4, GeCl4, POCl3, and FeCl3. The chemicals are used in such a way that step index single mode fibre can be drawn. The fibre drawing process consists of various steps such as heating the preform at elevated temperature, diameter monitor, primary and secondary coating, and ultra violet radiation curing. The fibres are then characterized for their geometrical and optical properties. The drawn fibre has diameter of core and cladding to be 8.3 μm and 124·31 μm, respectively whereas non-circularity is found to be 4·17% for core and 0·26% for cladding as seen from phase plot. Mode field diameter is found to be 8·9 μm and 9·2 μm using Peterman II and Gaussian method, respectively. The fabricated fibres showed the signal attenuation of 0·35 dB/km and 0·20 dB/km for 1310 nm and 1550 nm, respectively as measured by the optical time domain reflectometer (OTDR).