Third Harmonic Generation Enhanced By Defective Plasma Bragg Gratings.

Plasma Bragg grating is composed of periodic variations of plasma and dielectric or vacuum. The characteristic of the bandgap of the plasma Bragg grating without or with defect is studied by theory and particle-in-cell (PIC) simulation. A one-dimensional (1D) defective plasma Bragg grating is proposed to increase the conversion efficiency of the third harmonic of the incident laser pulse as compared with a simple plane target. In such a structure, the high laser field intensity and high plasma density are produced by laser localization in defect states, from which the third harmonic is enhanced by one order of magnitude. [ABSTRACT FROM AUTHOR]