Broadband Tamm plasmon polariton
A broadband Tamm plasmon polariton localized at the interface between the Bragg mirror and a thin metallic layer has been theoretically and experimentally investigated. The possibility of a localized state formation has been demonstrated and energy coefficients at the Tamm plasmon polariton wavelength have been predicted in the framework of the coupled mode theory. The metallic layer material and thickness corresponding to the maximum coupling between the incident radiation and the Tamm plasmon polariton has been determined. Experimental reflectance and transmittance spectra of the structure consisting of the Bragg mirror and chromium layers of different thicknesses have been measured. The analysis of the energy spectra shows the existence of the wavelength range with the near-unity absorption coefficient inside the Bragg mirror bandgap. The use of chromium as a metal results in the broadband Tamm plasmon polariton excitation. It is demonstrated that the experimental data is in a good agreement with the calculation.