numerical analysis of enhanced photodetector in terahertz spectrum

we report numerical analysis based on finite element method to characterize the performance of photodetector in terahertz band. in this paper based on the fabry-perot cavity rules, we propose an enhanced photodetector, which au rods and au film constitute its cavity. to have optimizing cavity, we investigate the geometrical parameters on absorption spectrum. our calculation shows that the absorption can be enhanced by about 55 times in the active region of terahertz photodetector compared to conventional photodetector without metallic cavity.