Theory and simulation of surface plasmon-coupled directional emission from fluorophores at planar structures.

A theoretical approach to surface plasmon-coupled emission (SPCE) from planar structures is developed. It is used for simulations. The results are compared to experimental findings. The match is almost perfect concerning emission angles. Power relations and decay times are reproduced qualitatively. The theory is based on Fresnel plane wave refraction at planar multilayered structures and the Weyl identity for expressing the dipolar radiation in terms of plane waves. One-dimensional integrals, used for the numerical computations, are derived for the fields, powers, and decay enhancements. This theoretical approach is shown to be well suited for design of SPCE setups and for prediction and explanation of experimental results. It also shows promise for refinement and optimization of SPCE, concerning enhancement of weak fluorophores, and usage of decay times.