Generation and detection of blue 10.0-fs pulses

Abstract
We report the generation of 10.0-fs optical pulses at a center wavelength of 438 nm by extracavity frequency doubling of a 10–11-fs Ti:sapphire laser followed by prism–grating dispersion compensation. To our knowledge these are the shortest pulses that have been generated in the blue region of the spectrum. We argue that the value of 10.0 fs is still limited by the 20-μm thickness of the freestanding autocorrelator doubling crystal. The well-behaved laser spectrum supports a 7.6-fs pulse. Studies of both the generation and the autocorrelator second-harmonic crystal thickness are presented.