On the emission pattern of nanoscopic emitters in planar anisotropic matrix and nanoantenna structures

Single nanoscopic emitters embedded in the crystalline matrix have become a valuable resource for emerging nanophotonics and quantum technologies. The generally anisotropic nature of the matrix strongly affects the emission properties of the quantum emitters, in particular, when the matrix is assembled in nanophotonic structures. We report on rigorous analysis and engineering of spontaneous emission from single emitters coupled to nanoantenna and planar anisotropic antenna structures. By developing a convenient theoretical method with efficient numerical implementation, we show that accurate modeling of the anisotropy is essential in predicting the emission pattern for many important systems, such as single molecules in the solid-state matrix, isolated defects in 2D materials and so on. In particular, we illustrate the amplified effects of material anisotropy and geometrical anisotropy for emitters coupled to planar antenna and nanoantenna structures. We show that with an appropriate design of the anisotropy, a strong enhancement of the emission rate and a nearly collimated beam from single emitters can be simultaneously achieved.