摘要
Abstract
An analysis of Smith-Purcell superradiation from subwavelength holes array(SHA) is carried out with the help of three-dimensional Particle-In-Cell code. The two-asymmetric grating is applied to modulate the electron beam and the dispersion curve of the two-asymmetric grating is numerical calculated by MATLAB while the dispersion equation calculated in theory. Using emission voltage U=50 kV, emission current I=30 A/cm2, the wave interaction frequency point is about 0. 3 THz which fall into the terahertz regime. The final simulation result is 0. 31 THz which matches the theoretical value well. We choose 0. 3 mm as the period of the subwavelength hole array. According to the S-P radiation formula, the second harmonic at the frequency of 0. 62 THz would radiate at the angle of 60. 7° which has good agreement with the simulation result. In the radiation zone, the amplitude of second harmonic wave is five times more than the amplitude of the fundamental wave, which most of the energy is the second harmonic at the frequency 0. 62 THz.关键词
孔阵列/Smith-Purcell/超辐射/太赫兹Key words
Holes array, Smith-purcell, Superradiation, Terahertz分类
数理科学
