Comparative modeling of focusing of femtosecond pulses

摘要

The comparative modeling of focusing of femtosecond Gaussian and Poissonian pulses was presented in this paper. Poissonian spectral shape pulses, as opposed to the Gaussian-shaped ones, allow to avoid negative frequency components. The spectral properties of pulses for various durations are investigated. Calculations showed that a significant difference between the Gauss and Poisson pulses begins only for very short durations (less than 3 fs). A comparative simulation of the focusing of short pulses, as well as the passage of focused pulses through a binary phase plate, is performed. The calculation was carried out on the basis of solutions of the Maxwell equations by the method of finite differences in the time domain.