Theoretical Study On Laser Cooling, Trapping, Manipulating And Controlling Of Three-level Atoms

In last two decades, the theoretical and experimental study on laser cooling, trapping, manipulating and controlling of neutral atoms has obtained many fast development and important progress. In this thesis, the general situation and recent progress on laser cooling, trapping and guiding of neutral atoms and experiments of Bose-Einstein Condensate have been first briefly introduced and reviewed. Afterwards, laser cooling, trapping, manipulating and controlling of three-level atoms are studied in detail theoretically. In final, our research work is summarized and the future investigation is briefly looked ahead.Using the dressed-atom approach, the general analytic expressions of eigenenergies, eigenstates and their optical potentials of a A -configuration three-level atom system in a linearly-polarized laser light are derived. The derived general expressions on the optical potentials are valid for any laser detuning and the resulting maximum relative error is only 3% as I≤2.5×10⁶ W/m², which have been the most exact solutions for a three-level atomic system so far. The general expressions for the three-level dressed atom can be reduced as the same as the results in relative references under the approximation of a small saturation parameter.The general expressions of the average dissipative and dipole forces acting on a A -configuration three-level atom in an arbitrary light field are derived by means of the optical Bloch equations based on the atomic density matrix elements. There are a resonant property of the dissipative force and a non-resonant property of the dipole force on the three-level atom. There is a saturation effect of the average dissipative force in the high order Bessel beam (HBB). The Doppler limit of atoms in the molasses HBB is slightly below the conventional Doppler limit of hΓ/2k_B due to the orbital angular momentum lh of the HBB.We propose a new scheme to guide cold atoms using a blue-detuned TE₀₁ mode in a hollow metallic waveguide (HMW), where the TE₀₁ mode is a doughnut mode and has a maximum coupling efficiency of 96.7%. When the input laser power is 0.5 Wand its detuning is 3 GHz, the guiding efficiency of cold atoms in the straight HMW can reach 98%, and it will be almost unchanged with the middle bending of the HMW. The losses of the guided atoms in the HMW are very small, even can be...