Transverse-Mode Effect of Second-Harmonic Generation of Ultrashort Laser Pulses with Time Delay

We describe simulations of the transverse-mode effect of type II second-harmonic generation of ultrashort laser pulses with a time delay by numerically solving a set of wave-propagation equations. The results showed that intensity ripples appearing in the second harmonic wave primarily result from the second-order nonlinear process and are further amplified by the third-order nonlinear process.