In this paper, we discuss and analyze theoretically probeabsorption-amplification response in a four-level coherent atomic system with vacuum-inducedcoherence via changing the sign of the parameter f, with f denoting ...In this paper, we discuss and analyze theoretically probeabsorption-amplification response in a four-level coherent atomic system with vacuum-inducedcoherence via changing the sign of the parameter f, with f denoting the ratio of a pair of dipolemoments associated with a doublet of closely upper hypernne sublevels. We find that the amplitude ofthe probe amplification for the case f = -1 can be about one order of magnitude larger than thatachievable for the case f = 1. In addition, with respect to the case f = -1 the probe amplificationcan be maintained all the time with weak incoherent pumping for a wide range of the probe detuning.展开更多
文摘In this paper, we discuss and analyze theoretically probeabsorption-amplification response in a four-level coherent atomic system with vacuum-inducedcoherence via changing the sign of the parameter f, with f denoting the ratio of a pair of dipolemoments associated with a doublet of closely upper hypernne sublevels. We find that the amplitude ofthe probe amplification for the case f = -1 can be about one order of magnitude larger than thatachievable for the case f = 1. In addition, with respect to the case f = -1 the probe amplificationcan be maintained all the time with weak incoherent pumping for a wide range of the probe detuning.