Abstract

We demonstrate that in femtosecond pumpprobe experiments the signal is not always independent of the probe-pulse spectral shape. This is in contradiction to the common interpretation of these experiments, in which the pump-probe spectra are simply assumed to represent time-dependent absorption spectra. Indeed, the absorption of a sample as measured by a single low- intensity optical field is independent of its spectral shape.

© 1995 Optical Society of America