高密度光栅自成像中的偏振效应

The Polarization Effect in Talbot Self-imaging of High Density Gratings

利用时域有限差分方法分析了不同偏振态下,不同周期高密度光栅1/2泰伯距离处的自成像,数值结果显示当光栅周期在2λ～3λ时,不同偏振态下,光栅的自成像差别最大。采用扫描近场显微镜技术,在实验上验证了这一现象。同时,利用严格耦合波方法分析了光栅的傅里叶谱,即远场分布,发现同近场分布存在着一定的对应关系。

The Talbot self-imaging of high density gratings with different period at half Talbot distance for different polarization is analyzed with finite-difference time-domain （FDTD） method. The numerical results indicate that the Talbot self-imaging of high density gratings for different polarization shows the biggest difference for the the grating period d between 2λ and 3λ. This is verified by experimental results with the scanning near-field optical microscopy （SNOM） technique. The Fourier spectrum （far field） generated by the gratings are analyzed with the rigorous coupled-wave method, which is in agreement with the near field.