Resonant signal transmission in optical structures with periodical profile of permittivity

Abstract

We consider a general physical approach to enhance the efficiency of terahertz bolometric detectors. The approach is based on the concept of resonant tunneling of an electromagnetic wave which is similar to quantum particle tunneling in quantum mechanics. Placing resonator under nontransparent conductive layer (plasma, metal or superconductor) helps to increase under certain conditions the field intensity both beyond the nontransparent layer and within it, thus enhancing the detection efficiency. If the frequency of the incident radiation matches with one of the eigenfrequencies of a resonator the effect of resonant tunneling through the conducting layer can be observed. Replacing single resonator with a resonator sequence separated with conductive layers result in formation of an absorption band instead of one resonant frequency. The calculations have shown that absorption of up to 60% of the energy of the THz pulses can be easily achieved in the considered structures even at the detection of broadband radiation.