Beam-distortion enhanced terahertz radiation generation in air

Abstract

Here we for the first time report an enhancement of terahertz (THz) radiation generation in air by a partial blocking of bichromatic pump beam consisting of the femtosecond Ti:Sapphire laser fundamental and its second harmonic. Both the experimental results and numerical analysis of the generation process demonstrated an increase of THz radiation yield by 15–20 percent over a wide range of the pump power and other experimental parameters. The dominant mechanism of THz radiation generation enhancement was found to be the pump pulse splitting suppression during its propagation in the plasma channel induced by the distorted beam.