Electromagnetically induced transparency based six-wave mixing in a Doppler-broadened folded four-level system     

牛金艳  裴丽娅  吴令安  傅盘铭 《海洋学报(英文版)》2010,29(11)

We study phase-conjugate six-wave mixing spectroscopy based on electromagnetically-induced-transparency in a Doppler-broadened folded four-level system. It is found that the six-wave mixing spectrum can be either Doppler-free or very broad, depending on whether the interference between the polarisations of atoms with different velocities is constructive or destructive. To obtain the Doppler-free six-wave mixing spectrum in the folded four-level system, the conditions are more stringent in comparison with those in the cascade and N-type four-level systems. This polarisation interference can be controlled in the presence of a strong coupling field.  相似文献