We focus on the transmission and reflection coefficients of light in systems involving topological insulators (TIs). Due to the electromagnetic coupling in TIs, new mixing coefficients emerge, leading to new components of the electromagnetic fields of propagating waves. We have discovered a simple heterostructure that provides a 100-fold enhancement of the mixing coefficients for TI materials. Such effect depends on the TI's wave impedance and the selected material for the sublayer. We also predict a transverse deviation of the Poynting vector due to these mixed coefficients contributing to the radiative electromagnetic field of an electric dipole. Given an optimal configuration of the dipole-TI system, this deviation could amount to 0.28% of the Poynting vector due to emission near nontopological materials, making this effect detectable.