Fano profiles in transmission spectra of terahertz radiation through one-dimensional periodic metallic structures

The transmission properties of broadband terahertz radiation through one-dimensional periodic metallic structures are investigated experimentally, and the obtained results are explained theoretically. Characteristic minima known as Woods anomalies are observed in the transmission spectra. The measured line shapes, the so-called Fano profiles, are caused by the coupling between resonant surface plasmons excited on the metallic grating and nonresonant diffraction orders. Numerical simulations using classical electrodynamics are in good agreement with the experiments.