Study of Extraordinary Optical Transmission in THz Region

• Main Authors: Hunag, Pin-Wei, 黃品維
• Other Authors: Lee, Chien-Ping
• Format: Others
• Language: en_US
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/86644878282177733189

碩士 === 國立交通大學 === 電子工程系所 === 97 === This thesis studies the physical origin of a very popular research theme, extraordinary optical transmission (EOT) phenomenon, in THz region. It is known that 2D periodic metal hole arrays can cause EOT; however, the real physical mechanism of this phenomenon is under debate. In THz region, good conductors can be seen as perfect electric conductor and therefore the explanation based on theory of surface plasmon ploariton (SPP) is improper. The first part of this thesis is theoretical formalism. We expand the EM fields of the system by eigenfunctions of Helmholtz’s equations in each sub-system, and then match the boundary condition obeying Maxwell’s equations. The simulation results match very well with experiment results, and so that we can exclude the SPP effect in THz region. In the second part we investigate the influence of hole shape and size on transmission spectrum. It is shown that, 1) the smaller the hole area, the higher the absolute transmission efficiency, 2) the aspect ratio of holes can cause shift in the peak transmission spectrum non-monotonously, and 3) the symmetry difference between hole and unit cell also has influence on transmission spectrum. These properties can be taken as a guide for future micro-optic THz device.