The Enhanced Kerr Nonlinear Effect In AΛ-type Three-level Atomic System And Laser Cooling And Trapping Of ～(87)Rb

Kerr-type nonlinear x³ coefficients play an important role in nonlinear optics and quantum optics. They have found various useful applications, such as cross-phase modulation(XPM) for optical Kerr shutters, quantum nondemolition measurement, optical communication, optical logic gate and signal photon. In recent years, one can gain resonantly enhanced nonlinearity based on an electromagnetically induced transparency without the absorption due to quantum interference. This is very significiant in the quantum computation, all-optical switch, quantum logical gate and signal photon. And in the Raman transition one can also obtain enhanced nonlinear effect due to atomic coherence. In the cold atom, the effect of Doppler broadening is eliminated and the collision perturbation is negligible. This can significantly enhance the effect of quantum coherence which has been interested in the field .There are two parts in the thesis. In the first part, we introduce the enhanced Kerr nonlinearity in EIT and Raman transition of A-type three level atomic system. Then described the realizing of cooling and trapping of ⁸7Rb atom by the simplified apparatus in the experiment. The main work and the results are as follows:1) The enhanced mechanism of Kerr nonlinear effect for cross-phase modulation of a three-level A-type atomic system via electromagnetically induced transparency (EIT) is theoretically analysed. Also the cross-phase...