الفهرس 
Interferometric Stydiel On Flbrl •Only 14 pages are availabe for public view
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Abstract
In this work, optical properties of polymeric and glass fibres were studied. The first part deals with interferometric studies in poiymeric fibres and glass optical fibres. The multiple-beam Fizeau fringes method is used to measure the refractive index, birefringence, polarizability per unit volume and optical orientation function for unirradiated and gamma irradiated nylon-6 fibres. The same optical properties are measured using two-beam interferometric method for polypropylene drawn at different draw ratios. The interference fringe shift and the area enclosed under it, were used to obtain the refractive index profile of optical fibres using three different methods. In chapter I the theory is given for fibres of circular cross-section or irregular cross-section in case of tep or graded index. In chapter II experimental results are reported. Using the multiple beam interferometric method it was found that the optical orientation function increases with increasing the dose according to a given empirical formula. The relation between the dose and the value of (Aa/3ao ) where ~ and ao are the polarizability per one molecule and its isotropic polarisability , respecrvely, which depends upon the molecular structure of the polymer have been studied, The result indicates that the gamma -irradiation of nylon-6 fibers affect the orientation in these fibres and the molecular structure remains unchanged . The two beam interferometric method is used to study the effect of drawing on the polypropylene structure.