Optical properties of Nd~(3+)- doped silica fibers obtained by sol-gel method

摘要

The Nd~(3+)-doped sol-gel silica fiber of clad-polymer type, 125 #mu#m in diameter, was pulled from thepreform with concentration of active ions of 0.03 mol. percent.The optical properties of such a fiber were investigated andcompared to monolithic samples. The attenuation factor for thisfiber was determined at 1.08 #mu#m to be 90 dB/km. Thedifference in emission spectra between neodymium-doped sol-gelsilica bulk samples and fibers manifesting in a significant shiftingof the peak emission of ~4F_(3/2) -> ~4I_(11/2) transition wasobserved. The fluorescence of Nd~(3+) silica gel fiber wasmeasured as a function of length of fiber and excitation power. Itwas found that the fluorescence intensities and lifetimes wereslightly dependent on fiber length. Moreover it was noted that theintensity of fluorescence increased linearly with power.