Interferometric measurements of femtosecond group delay in optical components

Abstract

We report direct measurements of the frequency dependence of the optical group delay for a number of optical components commonly used in femtosecond optics. We have investigated the group-delay errors that occur on reflection from metal and dielectric mirrors under various conditions and passage through devices that introduce angular dispersion. We obtain measurement accuracy of about ±1 fsec over the spectral range of 400–750 nm.