Effect of various chirped frequency functions on Gaussian laser beam characteristics

Abstract

In this paper, a chirped Gaussian laser beam with a general chirped frequency function has been considered. In order to find how the chirping frequency can affect Gaussian laser parameters, the wave equation governing the electric field of the laser beam was solved in paraxial approximation, self-consistently. The parameters of the chirped laser beam, such as the Rayleigh length, beam waist radius, spot size, as a function of the chirped frequency, have hereby been presented. Several different chirping functions, including linear, quadratic, Gaussian, exponential and sinusoidal ones, were employed to compare the effect of frequency chirping type. It was shown that the chirping, as well as the kind of chirping of laser frequency, plays an important role in the evolution of the laser parameters along the pulse length. It has also been shown that a Gaussian chirped frequency function can provide a more effective laser intensity distribution, which can be useful in laser-driven charged particle acceleration. Yet another notable result is the reshaping of the laser pulse due to its chirping frequency which can be considered important for numerous applications of the laser pulse.