The Research on Linear and Nonlinear Susceptibility in Four-level and Three-level Atomic Systems
|Keywords||Rabi frequency Energy level decay rate Nonlinear refractive index Optical ring cavity EIT|
The atomic coherence inversion laser , the enhancement of the nonlinear process , the storage of light pulses and laser cooling in many areas of quantum optics has a potential application value . We did a series of in-depth study , two of the main contents of this article : first , to study the atomic coherence effects in the N-type four-level atomic system . Compared with the three - level atomic system , four-level atomic coherence can lead to the generation of electromagnetically induced transparency can produce the phenomenon of electromagnetic induction absorption , depending on the size of the control of the intensity of the light and the fourth level decay rate . Second, in theory, calculated for an A -type three-level system of nonlinear optical ring cavity measuring medium refractive index . The calculation results show that near resonance at the atomic two-photon cross-phase nonlinear refractive index n 2 and cross- phase shift dramatically increase . This system has an important value in the development of optical information processing devices .