Tunable terahertz radiation from arbitrary profile dielectric grating coated with graphene excited by an electron beam
Zhao Taoa),b), Zhong Ren-Bin†a),b), Hu Mina),b), Chen Xiao-Xinga),b), Zhang Pinga),b), Gong Sena),b), Liu Sheng-Ganga),b)
       
(a) Frequency at the Brillouin center of the second dispersion band and band gap versus the asymmetry factor a 1. (b) Radiation intensity with frequency at the Brillouin center of the second dispersion band in vacuum and substrate sides versus the asymmetry factor a 1. Other parameters are the same as that used in Fig.  4 .