科研之友
微信
新浪微博
Facebook
分享链接
摘要
Based on the finite-difference time-domain method, we investigate the transmission resonances of compound metallic gratings with two subwavelength slits filled with different dielectrics inside each period in the visible and near infrared regions. The results show that the transmission spectrum is almost a compound of that of two corresponding simple gratings expect for the transmission feature at a certain resonant wavelength, where the Fabry-Perot (FP)-like phenomena have been found both inside the two slits, but the orders of the FP-like modes are different. If the order of the FP-like mode inside one slit is one bigger than inside the other, the intensity of the transmission will be significantly weakened. We attribute this phenomenon to the phase resonance because the phases at the exits of the two slits are opposite to each other.
