Collective effects in subwavelength hybrid systems: A numerical analysis

Optical properties of ensembles of coupled three-level quantum emitters are investigated in linear and non-linear regimes. The model of the Maxwell-Liouville von Neumann equations is implemented to explore the reflection, transmission, and absorption of a thin layer of atom-like emitters at low and high densities. The stimulated Raman adiabatic passage is analysed in systems of coupled quantum emitters of various densities. It is shown that coupling via local electromagnetic fields shifts the energy levels and modifies propagating fields leading to a mixed final population distribution and appearance of new absorption resonances. Strong femtosecond pulses induce population inversion in emitters leading to optical gain.