Measurement of pump induced refractive index change in Er~(3+) doped fiber by two-mode interferometry

摘要

We present and demonstrate a method do determine the refractive index and absorption changes in a two mode fiber interferometer. Measurement on the 632 nm transitions in Er~(3+) silica fiber shows that refractive index and absorption changes result from ground and excited state transitions respectively. The GSA/ESA cross-sections ratio was found to be 14.