Tilted-pulse second-harmonic beam analysis for femtosecond to subnanosecond laser pulse-duration measurements

The possibility of extending the second-harmonic beam (SHB) method proposed originally for picosecond and subpicosecond pulse-duration measurements to the femtosecond region is pointed out. This can be achieved by introducing a differential time delay of the pulse wave front corresponding to a tilting of the pulse in the direction other than that applied by Wyatt and Marinero, and also by Saltiel et al., who achieved extensions towards the subnanosecond region. The solution of the wave equations for noncollinear second-harmonic generation in the case of arbitrarily tilted pulses has been carried out. Simple formulae valid from the subnanosecond to the femtosecond region are presented.