Effect of Boundary Condition and Periodical Extension on Transmission Characteristics of Terahertz Filters with Periodical Hole Array Structure Fabricated on Aluminum Slab.

Terahertz (THz) filters based on extraordinary optical transmission from periodical hole array structures fabricated on aluminum slab have been experimentally investigated by using THz time-domain spectroscopy. The incident THz pulses with frequency from 0.1 to 2.7 THz could be partly filtered, and the central peak was at ∼0.26. The high frequency signal could be observed to decrease, especially for the frequency above ∼1 THz. Moreover, the transmission peak from small-size sample with less hole arrays shifts to high frequency at ∼0.53 THz due to both the effects of boundary condition and insufficient periodical extension. Furthermore, finite element method with surface plasmon polariton theory is employed to analyze this extraordinary optical transmission and filter phenomena. [ABSTRACT FROM AUTHOR]