Influence of the finite conductivity on the excitation of phase resonances in metallic surfaces with cavities of circular cross section

CLAUDIO VALENCIA,; DIANA CARINA SKIGIN

APPLIED OPTICS

OPTICAL SOC AMER

Lugar: Washington; Año: 2016 vol. 55 p. 9659 - 9667

0003-6935

Phase resonances have been investigated in the last few years, not only because of their striking features, such as extremely high quality factor and huge enhancement of the electromagnetic field inside cavities/grooves, but also for their promising applications. However, taking into account that these resonances are more efficiently excited inhighly conducting structures, most of the studies have been devoted to explore this phenomenon at wavelengths in the infrared or larger, using different approaches for the boundary conditions. In this paper, we investigate the validity of the perfect conductor approximation and the surface impedance boundary condition to appropriately represent theelectromagnetic response of a metallic surface comprising a finite number of subwavelength cavities of circular cross sections. Far- and near-field plots are shown and analyzed in order to investigate the validity ranges and discuss to what extent phase resonances can be excited at shorter wavelengths in these structures.