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 SiCl 4 , GeCl 4 , POCl 3 , and FeCl 3. 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 µ µm and 124⋅ ⋅31 µ 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 µ µm and 9⋅ ⋅2 µ 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).

The optical properties of single mode fibers, which are drawn from the silica preform made by MCVD technique, have been studied. The properties such as cutoff wavelength, chromatic dispersion, and polarization mode dispersion (PMD) were studied for 2.3 km length of single mode fiber (SMF). The cutoff wavelength was measured by fiber optic test procedure (FOTP)-80 which was found to be 1179 nm. The chromatic dispersion was measured by FOTP-169 at various wavelengths, the zero dispersion being observed at 1503 nm. The PMD was measured by interferometric method, and exhibited the magnitude of 0.07 ps at 1550 nm. The results are discussed to assess the suitability of these fibers for long haul communication systems.