理论分析了利用马赫-曾德干涉仪及平衡零拍探测技术测量相干介质色散特性的方法, 实验测量了三能级铯原子分别在电磁诱导透明和电磁诱导吸收两种截然相反的相干效应下的色散特性.研究表明: 在原子频率共振中心, 对于透明介质, 由于吸收减弱效应, 信号光能穿出介质, 保证了有效色散信息, 即正常色散特性能被测量到; 相反地, 对于吸收介质, 由于强吸收效应, 只有在低粒子数密度条件下, 即保证有信号光没有被完全吸收而穿出介质, 才能测量到介质的反常色散特性; 当提高铯泡温度时, 介质对信号光吸收增强以至完全吸收,并且吸收频谱宽度变宽, 导致色散信息不能被有效测量到.

The measurement of the dispersion properties of the coherent medium by using homodyne method based on Mach-Zehnder interferometer is analyzed in theory, and then the dispersion properties of three-level Cs atoms medium in two completely opposite coherent effects, electromagnetically induced transparency and electromagnetically induced absorption, are experimentally measured. The results show that at the atomic resonance center, the signal light can pass through the medium due to reduced absorption for the electromagnetically induced transparency medium, which ensure the measurement to the effective dispersion properties information, namely normal dispersion. On the contrary, for the electromagnetically induced absorption medium, due to the strong absorption effect, only at the low atomic densities, i.e. to ensure the signal light through the medium without being fully absorbed, the anomalous dispersion properties of the medium can be measured. Furthermore, when increasing the atomic number density, the absorption of atoms to signal light is enhanced to full absorption, and the absorption spectrum width is widened, which leads to the fact that phase shift can not be effectively measured.