Empirical study of the group delay dispersion achievable with multilayer mirrors.

With the help of the most advanced algorithms we obtained many dozens of multilayer dispersive mirror designs to empirically find limits for the maximum achievable negative value of the group delay dispersion (GDD). This value depends on the total thickness of coatings and layer material combination. Nb(2)O(5)/SiO(2) and Ta(2)O(50/SiO(2) combinations are studied in detail, for combinations HfO(2)/SiO(2) and TiO(2)/SiO(2) we obtained estimations for two bandwidths. We also show that reasonable values of third-order dispersion have no significant impact on the obtained results. Current state-of-the-art technology allows to produce designs with total physical thicknesses slightly higher than 10 µm and to achieve maximum negative GDD values corresponding to this total design thickness. Designs with total physical thickness of 15 µm and 20 µm are not realized yet due to high sensitivity to deposition errors.