Electron Beam-Induced Airy Beam-Like THz Radiation from Graded Metallic Grating

We have numerically analyzed an electron beam -induced Airy beam-like terahertz (THz) radiation from graded metallic grating structures with graded groove spacing (GGS) based on a simplified particle-in-cell finite-difference time-domain method. Airy beam-like directional THz beams are obtained from GGSs designed to give appropriate phase delay in each scattered radiation from each grooves. Our findings may open the way for a development of novel THz radiation source based on the wide variety of metallic grating structures.