Resonant tunneling condition and transmission periodic characteristics for a metal barrier in the Fabry–Perot cavity

Electromagnetic tunneling through a metal barrier cladded by dielectric layers is a distortion of the Fabry–Perot echelon. In this research, we clearly defined the distorted region based on the resonant standing wave pattern. For a specific electromagnetic frequency, its transmission oscillates periodically with the dielectric layer thickness and the metal barrier location, respectively. For both cases, the period equals to the corresponding half wavelength in the dielectric material. We formulate the general resonant condition and also discuss the consequence of energy loss in the metal layer. Our results provide new physics insight into this phenomenon and will help engineering design for the potential devices based on this electromagnetic tunneling effect.