相干热原子介质中的电磁感应成像

Electromagnetically Induced Self-Imaging in the Hot Atomic Medium

研究了热原子介质在电磁感应透明（EIT）条件下的近梯度折射率性质。理论研究表明，在考虑多普勒加宽后，介质仍能对物体起到自成像的作用。利用分步傅里叶方法，采用方格矩描述横向传输面的归一化点光强，同时引入像面差异因子，用于寻找精确像面位置并对成像质量进行评价；研究了温度对像面位置与成像质量的影响，结果表明，随着温度的升高，像面与物面的距离几乎呈线性增加，而成像质量呈线性下降。

The approximate gradient index is formed under the condition of electromagnetically induced transparency （EIT） in the hot atomic medium. Theoretical study shows that, self-imaging can also be induced after considering Doppler broadening. With the split-step Fourier medthod and lattice matrix, normalized intensity distribution on the transverse transmission plane is studied. With the definition of difference factor of image plane, the location of the self-imging can be calculated accurately. The influences of the temperature on the position of the self-imaging and the corresponding imaging quality are discussed in detail. Numerical results show that, with the increase of the temperature, the location of the self-imaging linearly moves away from the original object, and the self-imaging quality decreases.