Subfemtosecond compression of periodic laser pulses

It is shown that a recently proposed technique of molecular modulation can be used to compress mode-locked laser pulses into the subfemtosecond domain . The method relies on driving a molecular oscillation with a periodic puls e train. The coherent molecular motion, in turn, modulates the laser freque ncy and allows pulse compression by group;velocity dispersion of the same m olecular medium. (C) 1999 Optical Society of America.