The group delay of multilayer laser mirrors was measured by determining the spectral position of transmission maxima of a Fabry-Perot interferometer formed by the mirrors to be characterized. By optimizing the spacer thickness, we obtained an accuracy of the group-delay measurement of better than 0.23 fs. To our knowledge, this is the most precise direct measuring method reported.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics