Photonic Crystal Behavior Of Atomic Theory Research

Today,there are many experiments of photonic crystal (PhC) laser in the world. But in the theory, we can get only some shaping or determined conclusions from the parse theoty. Most of the numerical calculate existed only get the distributing of latent light field and the Q value of small cabity. In this paper ,we study the interacting between source and the light field by means of the finite-difference time-domain (FDTD) method . We study two kinds of source: free dipole and atom of two class. and get the radiation speciality of the source.In this paper we calculate the radiation speciality of free dipole in PhC structure firstly. The radiation of the free dipole is restrained in the PhC Gap. The radiation at the frequency of the defected model is amplied. We analyse the infection of radiation of the free dipole impressed by the position of source.Secondly we get the radiation character of the excited atoms by semi-classical theory , in which the action of atoms are described by density matrix and the light field is described by Maxwell equations. By calculated, we find the radiation of the excited atoms is inhibited in the gap of 2D PhC,while,the excited atoms whose frequency are the defected mode frequency can maintain the Rabi surge in 2D defected PhC.At last, we introduct the laser by population matrix. We get the conclusion that the defected PhC can reduce the threshold value effectively.