在原子相干效应条件下，由于场与原子之间的相干耦合，导致原子能态的相干叠加，因而导致与之作用场的光场特性发生变化。本文研究了两束光与原子样品相互作用下，量子化光场的噪声谱，结果得到了在一定的失谐范围内，光场起伏存在1．25dB的压缩，继而可以用来实现量子起伏纠缠。

The coherent superposition of atomic states leads to the change of properties of interaction lights because of the coupling between the lights and atoms. In this paper,the noise spectrum of the quantified light interacting with the atoms is studied;it shows that the squeezing of 1.25 dB can be observed at the detuning of probe light,which then can be used to get the entanglement.