Physical Review A
Spontaneous emission from a medium with elliptic and hyperbolic dispersion
Zhengjun Liu, Wei Li, Xunya Jiang, Juncheng Cao
Abstract
We analyze the properties of spontaneous emission of a two-level atom in anisotropic media where the geometry of physical dispersion relations is characterized by an ellipsoid or a hyperboloid. Within the framework of quantum optics the rate of spontaneous emission in the above media is explicitly given with the orientation of the dipole transition matrix element taken into account. It indicates that for the ellipsoid case the intensity of the photons coupled into different modes can be tuned by changing the direction of the matrix element relative to the optical axis. For the hyperboloid case it is found that spontaneous emission in the hyperbolic medium (HM) can be dramatically enhanced compared with the case in the background medium. Moreover, in the HM the spontaneous emission exhibits strong directivity and gets the maximum in the asymptote direction.