The Multi-photon Resonant Nondegenerate Multi-wave Mixing In The Middle Level Via Quantum Interference

Multi-wave mixing is a widely recognized spectroscopic technique. It can be effectively used for studying highly excited states and high angular momentum states with high resolution. It processes features of excellent spatial signal resolution, free choice of interaction volume and phase matching can be achieved for a very wide frequency range from several hundreds to thousands of cm-1; The signal of multi-photon resonant multi-wave mixing can be enhanced several orders of magnitude because all the transitions are in resonance. The thesis is divided up into the following two parts:In the first part of this thesis we studies the two-photon resonant nondegenerate four-wave mixing (NFWM) in the middle level via quantum interference. Our method can study transitions between two highly excited atomic states, which have very long radiative lifetimes that a direct detection of the fluorescence is difficult. The doppler effect is considered into the two-photon resonant nondegenerate four-wave mixing, and the interference between the polarizations of atoms with different velocities in dressed atomic system of the two-photon resonant nondegenerate four-wave mixing is investigated.The contribution of the polarization interference on the NFWM spectra is discussed in detail.In the second part of this thesis, we further study the three-photon resonant nondegenerate six-wave mixing in the middle level via quantum interference and the polarization-dependent interference effects in the three-photon resonant NSWM in the middle level via quantum interference.