An extension of the single-shot second harmonic beam method proposed earlier for picosecond pulse duration measurements is presented for the case of two incident pulses of differing frequencies, durations and transverse sizes. The solution of the wave equation for noncollinear sum frequency generation in a nonlinear crystal by two Gaussian, spatially limited ultrashort pulses is given. It is shown that the width (τ12+τ22)1/2 of the temporal cross-correlation function of the two pulses can be deduced from the spatial energy distribution of the sum frequency beam. The method can be used e.g. in the case of a relatively weak secondary pulse obtained in some nonlinear processes. Preliminary experimental results demonstrating the possibilities offered by the method are presented.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Electrical and Electronic Engineering