High-speed photography, spectra, and temperature of optical discharge in silica-based fibers

The dynamics of fiber fuse effect including process of bubble formation in fiber core was investigated. Bubbles in the core were observed not later than 20/spl divide/70 μs after the plasma forepart passed. For the first time, the temperature of optical discharge was measured for a wide range of laser radiation powers. For 40-W laser power, the temperature reached 10
⁴
K, the velocity of discharge propagation having increased to 10 m/s.