title: Spontaneous radiation and lamb shift in three-dimensional photonic crystals
abstract: Spontaneous emission in photonic crystals with anisotropic three-dimensional dispersion relation is studied. If the upper level is below a characteristic frequency omega(1), or above omega(2), or between omega(1) and omega(2), the radiation is a localized field with a frequency in the band gap, or a propagating field with a frquency in the band, or a diffusion field, respectively. An analytical expression for the Lamb shift is obtained. The Lamb shift for the current case is small compared to that in an ordinary vacuum or in one- or two-dimensional photonic crystals due to lower density of states.
authors.affiliation: Department of Physics, Hong Kong Baptist University, Kowloon Tong, Hong Kong and Department of Applied Physics, Shanghai Jiao Tong University, Shanghai, People's Republic of China.
authors.initials: SY
authors.lastname: Zhu
authors.initials: Y
authors.lastname: Yang
authors.initials: H
authors.lastname: Chen
authors.initials: H
authors.lastname: Zheng
authors.initials: MS
authors.lastname: Zubairy