Phase-locked two-color sub-40-fs double pulses in the visible are produced
by noncollinear parametric amplification of white light tailored in a pulse
shaper with a liquid-crystal mask. The carrier phase between the pulses is
conserved during the amplification process and can be adjusted, as can the
temporal separation and the center of wavelengths of the pulses. (C) 2001
Optical Society of America.