Generation of sub-10-fs pulses from a Kerr-lens mode-locked Ti : Sapphire laser using double-chirped mirrors with flat group delay dispersion

Abstract

We have generated sub-10-fs laser pulses from a Kerr-lens mode-locked Ti:Sapphire laser using a single set of commercially available simple double-chirped mirrors. Double-chirped mirrors which are deliberately designed for negative group delay dispersion allow pulses with a high-quality spectral shape and with a spectral bandwidth as broad as 143 nm to be achieved. Broad spectral tunability over a similar to 140 nm spectral range was achieved. Numerical simulations show that quadratic-chirped double-chirped mirrors have the advantage of weak oscillation in group delay over linear-chirped mirrors, but have the drawback of showing a more negative value of group delay dispersion at long,wavelengths, which leads to incomplete compensation of the intra-cavity group delay dispersion, Residual oscillations in the group delay could be compensated for effectively Over a bandwidth of 250 nm by using a pair of simple double-chirped mirrors designed to have shifts in dispersion characteristics, The analysis of these simple double-chirped mirrors with flat group delay dispersion showed good agreement with the characteristics of commercially available mirrors.