simulation domain with artificial absorbing boundaries via the convolutional perfectly matched layers (CPML) technique with 20 layers on each side. The latter corresponds to the artificial reflection coefficient of 10 -12 ensuring the numerical stability. In the present implementation, to achieve numerical convergence the spatial resolution was set at nm with a time step . The entire FDTD grid was taken 2 μm wide with the cavity placed in its center. The molecular slab is placed at the center of the cavity as shown in Fig. . The transition dipole,