Exponential Enhancement of Terahertz Power from an Asymmetric Plasma Filament Pumped by Two-Color Femtosecond Laser Pulses

Abstract

We have demonstrated an order of magnitude increase in terahertz (THz) power, and showed that such an enhancement might be attributed to formation of an asymmetric plasma profile in which the plasma density increases steeply in the head and decreases gradually in the tail. We solved a onedimensional model with and without accounting for amplification of THz wave. Comparison of these two cases implies that the THz wave may have been amplified during propagation in the plasma.