Properties of optical fiber preforms prepared by inner coating of substrate tubes

Substrate/deposit high-temperature interactions taking place at the standar d MCVD method, MCVD method combined with the solution doping and sol-gel me thod are experimentally investigated on preform cores composed of (P2O5)/Ge O2/SiO2 glasses and Al2O3/P2O5/SiO2 glass matrices doped with Yb and Er ion s. Effects of these interaction processes on the increase of the core radiu s, the content of dopants in the core and attenuation of fibers are shown. Conditions under which the interaction substantially affects the refractive -index profiles are found by comparing the theoretically estimated and expe rimentally determined characteristics. Attenuation of optical fibers used i n fiber-optic sensors and soliton fiber lasers which have been fabricated o n the basis of these results are shown.