Physical Review A
Spontaneous emission in an absorptive and inhomogeneous cavity
Kazuki Koshino, Akira Shimizu
Abstract
We consider the spontaneous emission (SE) of radiation by an atom in a one-dimensional cavity which consists of two medium regions and a vacuum region between them. The medium regions are composed of a bulk dielectric material which has a continuous absorption spectrum. We quantize the electromagnetic field as well as the polarization fields of the material, and polaritons composed of infinite number of fields are obtained. Using the polariton solutions, we then study the SE for an atom in such an absorptive and inhomogeneous cavity. The SE rate is shown to depend strongly on the position of the atom, the length l of the vacuum region, and the complex refractive index \ensuremath{\eta}+i\ensuremath{\kappa}. It is found in particular that the position dependence of the SE rate disappears for some particular values of l, in either of the vacuum or medium region. We also find that unlike the three-dimensional case the SE rate in a homogeneous cavity depends on both \ensuremath{\eta} and \ensuremath{\kappa}. \textcopyright{} 1996 The American Physical Society.