ULTRABROADBAND CHIRPED MIRRORS FOR FEMTOSECOND LASERS

We report on the performance of widely tunable femtosecond and continu ous-wave Ti:sapphire lasers that use a newly developed ultrabroadband mirror set. The mirrors exhibit high reflectivity (R > 99%) and smooth variation of group delay versus frequency over a wavelength range fro m 660 to 1060 nm. Mode-locked operation with pulse durations of 85 fs was achieved from 693 to 978 nm with only one set of ultrabroadband mi rrors. (C) 1997 Optical Society of America.