We show that the theory of potential transmittance (PT) is useful for problems involving photon tunneling through metal-dielectric stacks, regardless of whether the tunneling is mediated by Fabry–Perot or surface-plasmon resonances. A unifying principle is that, given a total thickness of metal, subdividing the metal into a larger number of thin films increases the maximum PT. For Fabry–Perot-based tunneling, we apply the concept of equivalent layers to stacks comprising dielectric-metal-dielectric unit cells and explore the conditions for impedance matching to an external air medium. This approach demonstrates that, to optimize transmittance, thicker metal films require higher-index dielectric spacers. For surface-plasmon-mediated tunneling, we confirm that the maximum transmittance also lies within the limits predicted by PT theory.
© 2011 Optical Society of America
Original Manuscript: May 17, 2011
Revised Manuscript: August 23, 2011
Manuscript Accepted: August 25, 2011
Published: September 29, 2011
T. W. Allen and R. G. DeCorby, "Assessing the maximum transmittance of periodic metal-dielectric multilayers," J. Opt. Soc. Am. B 28, 2529-2536 (2011)