Sub- and superluminance with gain in a three-level ladder-type atomic system with spontaneously generated coherence |
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| Authors: | Dingan Han Yaguang Zeng Weicheng Chen Hui Cao Hong Lu |
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| Affiliation: | 1. Department of Physics , Foshan University , Foshan 528000, People's Republic of China handingan@yahoo.com.cn;3. Department of Physics , Foshan University , Foshan 528000, People's Republic of China |
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| Abstract: | The effects of spontaneously generated coherence (SGC) on the propagation of a weak probe pulse are investigated in a ladder-type atomic system. Due to SGC, the properties of the dispersion and the absorption of a three-level ladder-type system are changed greatly. With proper parameters, the system can produce normal and anomalous dispersion regions in the gain region. The effects of the incoherent pumping and the relative phase on the group velocity are also studied. They all can be used as switches to manipulate the group velocity of the weak probe field from gain-assisted sub- to superluminance. |
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| Keywords: | SGC gain-assisted subluminance superluminance |
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