With the occurrence of an adding driving field, the properties of the dispersion and the absorption of a four-level system are changed greatly. The system can produce the normal and anomalous dispersion regions with p...With the occurrence of an adding driving field, the properties of the dispersion and the absorption of a four-level system are changed greatly. The system can produce the normal and anomalous dispersion regions with proper parameters. Here, the driving fields can be seemed as knobs to manipulate the group velocity of a weak probe field between subluminal and superluminal.展开更多
基金Supported by National Natural Science Foundation of China under Grant Nos.61008063 and 10547108the Key Project of National Natural Science Foundation of China under Grant No.60837004+1 种基金Natural Science Foundation of Education Department of Guangdong Province of China under Grant No.LYM08099Natural Science Foundation of Foshan University
文摘With the occurrence of an adding driving field, the properties of the dispersion and the absorption of a four-level system are changed greatly. The system can produce the normal and anomalous dispersion regions with proper parameters. Here, the driving fields can be seemed as knobs to manipulate the group velocity of a weak probe field between subluminal and superluminal.
