Numerical simulations on strong coupling of Bloch surface waves and excitons in dielectric-semiconductor multilayers.

ABSTRACT

Simulations on Bloch surface waves and Bloch surface wave-exciton-polaritons based on the transfer matrix method were performed using only the layer thicknesses and refractive indices of the materials. We demonstrate that the incorporation of the influence of active layer is necessary to accurately determine the Bloch surface wave dispersion. Furthermore, the mode splitting that gives rise to the lower and upper polariton branches can be simulated by including the full dispersive refractive index of the active layer in the transfer matrix calculation. We show the dependence of coupling strength on active layer and truncation layer thicknesses, which implies that the Bloch surface wave-exciton interaction strength can be tuned just by changing these structural parameters. Furthermore, we calculate the area inside the dips corresponding to the lower and upper polariton modes, which can serve as an indicator of mode visibility. We find that in the Kretschmann-Raether configuration, a tradeoff between high Rabi splitting and good mode visibility must be taken into account in designing multilayer structures for Bloch surface wave-exciton-polaritons. Angle-resolved reflectivity maps were also calculated to illustrate how these results can be observed in an experimental set-up. This work serves as a guide map in the design and potential optimization of multilayer structures for the study of two-dimensional polaritonic systems.