Relative contribution of geometric shape and periodicity to resonant terahertz transmission

We report the terahertz (THz) transmission characteristics of subwavelength slit arrays with a variety of structures ranging from periodic to random. THz electromagnetic wave transmission experiments clarify the relative contributions of the periodicity and the geometric shape effects to transmission enhancement. In the spectral region slightly below the first Rayleigh minimum, strong transmission enhancement is achieved through the contributions of both effects. In the long-wavelength region, however, enhancement is achieved even in the random arrays of slits because the slit shape has its fundamental resonance. The understanding of the mechanisms of resonant THz transmission is elucidated by using a theoretical approach that is based on a perfect conductor model. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3445780]