Strong mid-infrared radiation from self-guided fast electron bunch propagating along a grated target surface in laser-solid interaction.

Generation of 10¹² W/cm2 Smith-Purcell radiation in the infrared (5-20μm) regime from the interaction of high-density laser-produced MeV electrons is proposed. The electron bunch is produced by impinging an intense ultrashort laser pulse on a metallic target with a grated upper surface. Particle-in-cell simulation shows that the electron bunch can efficiently couple to the periodic structure through the quasistatic self-generated electric and magnetic fields there. An analytical model for predicting the dependence of the radiation intensity on the laser and grating parameters is also proposed. With appropriate laser and grating parameters, the proposed scheme provides a tunable source for intense radiation in the infrared regime. [ABSTRACT FROM AUTHOR]