Study On Light Propagation In Resonant And Non-resonant Media

In the thesis, there were mainly four parts. We studied the non-resonant and resonant propagation of light in the media and the optical properties of the media using the rotating frame from the Maxwell equations and density matrix equation. The non-resonant propagation of intense laser in the plasma channel was investigated firstly, and then a general method to study the resonant propagation of light in the dispersion media was given. In an abnormal dispersion media, there was a superluminal propagation, so the signal velocity was proposed. According to the signal-to-noise ration and bit-error-rate in the detection, the relation between the signal velocity and the pulse characteristics, such as the temporal profile, the phase and the propagation distance, was given. Further, from the energy levels of media, we analyzed the superlumianl propagation and sublumimal propagation and how to manipulate them. Finally, it was a conclusion and prospect.In the first part (Chapter 1 to 3), propagation of the ultrashort intense laser beam in the plasma channel was investigated theoretically. Chapter 1: The background of the study of propagation of ultrashort intense laser in plasma channel and a survey of the interaction of laser with plasma were introduced. Chapter 2: Characteristics of propagation of ultra-intense laser beam in a partially stripped preformed plasma channel was discussed, in which the relativistic self-focusing effect, together with the perturbed plasma density, was given. From Maxwell equations, the refractive index equation and Hamilton-Jacobi equation, which described the evolution of the electric field, were derived including the effects of the diffraction, the third-order intensity-dependent nonlinearity, the plasma defocusing, the focusing and defocusing of the plasma channel, and the relativistic self-focusing. The envelope equation of laser propagating in the plasma channel, and the general expression related the laser spot size with the propagation distance and the width of the plasma channel etc., were derived based on the Hamilton-Jacobi equation and the refractive index equation. Chapter 3: The source-dependent expansion (SDE) method for...