基于菲涅耳衍射理论分析了畴腐蚀二维周期结构掺镁铌酸锂晶体光分束器的泰伯效应，对光分束器不同占空比D及泰伯分数β条件下的近场光衍射自成像进行了数值模拟研究。设计并制备了不同占空比的畴腐蚀掺镁铌酸锂晶体光分束器，并对其进行了分数泰伯光衍射自成像的实验研究，得到了不同泰伯分数β条件下的近场光衍射强度分布。结果表明，当光分束器占空比D=52%、泰伯分数β=2时，近场衍射自成像效果最佳，实验结果与理论研究结果相符。

The Talbot effect of the two-dimensional optical beam splitter fabricated by selective etching of MgO-doped LiNbO3 (MgLN) crystal is analysed based on the Fresnel diffraction theory. Numerical simulation is applied to study the intensity distribution of near-field optical diffraction under various duty cycle D and Talbot distance coefficient β. Based on the theoretical result, the selective etching optical beam splitter is designed and fabricated with various duty cycles. Through optical experiments, the fractional Talbot diffraction imaging map is obtained at different Talbot distances. The results obtained show that good near-field diffraction images can be achieved at D=52%, β=2, which verifies the results of the numerical simulation research.