Abstract
Studies of anomalous Lamb shift in 2p/sub 1/2/ state of hydrogen for photon-atom interaction as a function of relative dispersion frequency, refractive index contrast and propagation vector using quadratic fluctuations and randomness in an anisotropic model of Brillouin Zone (BZ) for p polarization are reported. The anomalous Lamb shift in 2p/sub 1/2/ level is significantly more than that obtained by using isotropic model which indicates that odd parity 2p/sub 1/2/ state of hydrogen is significantly influenced by introducing anisotropic behaviour of BZ. This work is new and it is fruitful to provide information about optical properties in laser action within the photonic crystal.