Photosensitive fiber light guides made on the basis of borogermanosilicateglass

The technology is developed and samples produced of light guides with a bor ogermanosilicate core with the introduction of boron oxide during the time of exposure of a tube to vapors of boron bromide and oxygen. It is demonstr ated that the additivity rule may be used for an approximate calculation of the profile of the refractive index of borogermanosilicate glass. The phot osensitivity of these light guides is investigated, and it is found that an additional alloying with boron does not affect adversely the photosensitiv ity of light guides containing germanium oxide in their core but makes it p ossible to increase the mode spot diameter (up to 6-9 mum, depending on the glass composition).