High effective SHG of femtosecond pulse with ring profile of beam in bulk medium with cubic nonlinear response

摘要

Possibility of high intense second harmonic formation with beam profile and pulse shape, which are similar the Gaussian ones, under the cascading SHG with taking into account cubic nonlinear response of medium is shown. Laser pulse on doubling frequency has intensity that is comparable or greater than the one of basic harmonic. The duration of second harmonic pulse can be many times less than the first harmonic pulse duration. We take into account dispersion and diffraction of laser pulses and group velocity mismatching.