Effect of a thin dielectric layer on terahertz transmission characteristics for metal hole arrays

We studied the role of surface-plasmon polaritons (SPPs) in a bandpass transmission property of two-dimensional metal hole arrays (2D-MHAs) by investigating the effect of thin dielectric layers on the 2DMHA surfaces. We measured zero-order transmission spectra of the 2D-MRAs by changing the thickness of the dielectric layer and found that the bandpass transmission peak shifted to the lower-frequency side with increasing layer thickness, owing to the change of the resonant frequency of the SPR This result shows that SPPs play a crucial role in the transmission property of 2D-MH-As in the terahertz region. © 2005 Optical Society of America.