Resonance characteristics of transmissive optical filters based on metal/dielectric/metal structures

The resonance characteristics of the Fabry-Pérot resonator modes supported by metal/dielectric/metal planar structures are studied in the case of absorbing media for near-to-normal light incidence. Approximations based on rigorous solution and field-transfer model for the field and resonance line shapes in spectra are attributed to the class of Fano and Lorentz resonances. The analytical expressions are obtained for the propagation constant and field enhancement of the mode, width, height and slope of resonance line shapes in spectra as functions of structural parameters. With estimation of field characteristics of the fabricated loss structures based on aluminum and quartz, the peaks in the transmission spectra can be attributed to the excitation of Fabry-Pérot modes. Fundamental characterization of Fabry-Pérot resonances may find applications in optical processing and sensing.