Theoretical investigation of properties of filament pumped by Gaussian and super-Gaussian beams at relative low incident power

In this paper, the properties of filament generated by Gaussian and super-Gaussian laser beams are investigated systematically. Through theoretical calculations, it is found that the super-Gaussian beam can carry more energy and benefit generation of higher plasma density in comparison with standard Gaussian beam under the same condition. Our findings demonstrate that the properties of the filament can be easily manipulated by changing the spatial shape of the incident laser beam. In experiment, this method can be directly utilized by simply using diaphragmed input beams with steep intensity gradients. From the practical point of view, our findings imply that the super-Gaussian beam should have potential application in the field of ultrashort laser spectroscopy.