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 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 characterization of step index single mode silica fiber for long haul signal communication

“…First, preform fabrication 5 was carried out by means of conventional MCVD technique by using various dopants such as SiCl 4 , GeCl 4 , POCl 3 , and CCl 2 F 2 (freon 12). After fabrication, this preform was subjected to fiber drawing process.…”

“…The performance of optical fibers, specifically the transmission losses, bandwidth and strength, is strongly influenced by the fiber drawing and coating process. Fiber drawing proceeds 5 by heating the tip of the preform to a molten state and allowing it to extend under the force of gravity downward into a fine-diameter filament without the use of any die mechanism whereas pulling and winding mechanism sustains a drawing force. Then it immediately enters into the coating applicator.…”

“…Much stress is given to the fact that these fibers should have stable transmission characteristics in long lengths 3,4 with maximum reproducibility. Therefore, characterization of the fibers plays a crucial role for optical signal transmission, which is carried out mainly by observing attenuation using optical time domain reflectometer (OTDR), mode field diameter and core clad geometry 5 . Beside these factors, cutoff wavelength, chromatic dispersion and polarization mode dispersion also play an important role to define the properties of single mode optical fiber.…”

“…The various methods such as four wave mixing 9 , poincare sphere, polarimetric methods 10 have been reported for measuring the PMD. In this paper we report the characterization of single mode silica fibers that were made by MCVD technique 5 described by us previously. The optical properties reported in this paper are useful in assessing the drawn fibers 5 for long haul communication systems.…”