Measurement of fs laser-induced refractive index changes using an integrated optical interferometer

Abstract

The measurement of femtosecond pulse laser induced refractive index changes inside transparent solids is challenging since only small phase differences of buried structures on a micrometer scale have to be resolved. Here we report on a new technique that allows to precisely determine the laser-induced refractive index changes in situ. It is based on the modification of an integrated optical Mach-Zehnder interferometer.