Using 3.6- and 5.3-fs pulses, we demonstrated theoretically and experimentally that fringe-resolved autocorrelation (FRAC) traces are distorted by bandwidth limitations of the
second-harmonic generation (SHG) in 10-µm-thick, type I β -BaB2O4 for pulses shorter than sub-5 fs. In addition, detailed
numerical analysis of the SHG showed that the optimum crystal angle where the FRAC trace distortion becomes minimum is in disagreement not only with the phase-matching angle but also
with the angle where the FRAC signal intensity becomes maximum. Furthermore, the apparent pulse duration measured at a nonoptimum angle was confirmed to become shorter than that of its
transform-limited pulse, in excellent agreement with the calculated result.
© 2004 Optical Society of America
Equations on this page are rendered with MathJax. Learn more.