Single-mode W-type optical fiber stable against bending and radiation

It is shown that single-mode fluorosilicate optical fibers fabricated with the aid of modified chemical vapor deposition exhibit a significant decrease in the radiation resistance when 1 mol % GeO$_2$ is introduced into the silica-glass core. Elimination of chlorine and OH group impurities in the silica glass of the core of the fluorosilicate single-mode fiber leads to a relatively low level of radiation-induced attenuation. Prior to radiation processing, the loss factors of optical fiber are 0.18 and 0.3 dB/km at wavelengths of 1.55 and 1.31 $\mu$m, respectively. The dependence of optical loss of such fibers on the bend diameter ranging from 6 to 12 mm is studied.