Second-Harmonic Generation of a Short-Laser Pulse From a Gas-Jet Immersed in a Magnetic Field

A scheme for second-harmonic generation (SHG) of a short-laser pulse from a gas jet immersed in a magnetic field has been investigated. A laser pulse with sufficient intensity interacting with gas produces free electrons by tunnel ionization. The electrons accelerated by the laser pulse generate nonlinear currents at the second-harmonic (SH) frequency of the fundamental laser pulse. The ambient magnetic field provides an additional resonance to enhance the SH field amplitude. Based on the plasma current model, we estimate the SH field and provide various scaling laws for optimization and controlling the SHG process. This study might provide a new way to optimize the SH field from the laser interactions with a gas jet immersed in a magnetic field.