THz generation with transition radiation from the rear surface of a laser-driven foil

Abstract

Terahertz (THz) radiation has attracted increasing attention over last decades for its wide promising applications in many interdisciplinary fields of research. Since a plasma is free of damage, laser-plasma interactions have potentials to achieve tabletop high-field THz radiation sources. The THz sources provide opportunities to study nonlinear THz field-matter interactions. In this presentation, we will show generation of coherent THz transition radiation by relativistic laser-accelerated electrons crossing the rear surface of a thin solid target. To verify the generation mechanism, various target parameters and structures are adopted to characterize the THz radiation properties and to distinguish the proposed mechanism from others. The model of transition radiation and particle-in-cell simulations well explain the observations. The presented laser-solid based THz transition radiation provides a new approach toward compact brilliant THz sources.