Characteristics of Femtosecond Laser Interaction with the Two-Level Atom System in Optical Materials

With the development of laser technology, the femtosecond laser has been more and more extensively used both on scientific research and practical application. The interaction of femtosecond laser with two-level atoms in optical materials was discussed. The evolution of femtosecond pulse in resonant atomic medium with long distance, and the influence of the distribution of the laser field amplitude, which were Gaussian, hyperbolic secant, and asymmetric hyperbolic secant, on the two-level atomic transition probability is presented. Also the dynamic analysis of temporal evolution of atomic transition in a two-level system under the radiation of the frequency-chirped field in optical materials is analyzed.