采用外加高压脉冲电场的方法制备了二维谢尔宾斯基分形超晶格结构铌酸锂(LiNbO3)非线性光子晶体，对晶体中的准相位匹配和切伦科夫辐射谐频等光学特性进行了实验和理论研究。理论推导出了晶体中的准相位匹配倍频与不同阶次的倒易矢量间的对应关系，与实验结果吻合。对于同一个倒易矢量，可以实现两种波长的准相位匹配倍频。同时，实现了近红外波段的共线和非共线三倍频输出。理论计算出不同波长下的切伦科夫辐射倍频和三倍频的辐射角，与实验测量结果相吻合。在特定波长下，切伦科夫辐射谐频光环的辐射角存在最小值。同一个波长下，切伦科夫辐射三倍频的辐射角总是大于倍频的辐射角。

Lithium niobate (LiNbO3) nonlinear photonic crystals with Sierpinski fractal superlattices are fabricated successfully using high voltage electric field, and their quasi-phase matching and C?erenkov radiation harmonics are studied theoretically and experimentally. The relationship between the fundamental wavelengths and the order of quasi-phase matching harmonics is gotten theoretically. This result corresponds to the experimental value. For one reciprocal vector, quasi-phase matching second-harmonics of 2 kinds of wavelength can be accomplished. The collinear and non-collinear quasi-phase matching second- and third-harmonics in the near infrared wavebands are observed. The distribution of C?erenkov second- and third-harmonic radiation angles as a function of input fundamental wavelength are calculated and the results agree with the experiments. C?erenkov radiation angles reach the minimum at some certain wavelengths. C?erenkov third-harmonic radiation angles are larger than the secondharmonic ones at the same wavelength.