针对空间衍射成像系统对大口径、结构轻量化、空间可展开等特性的要求，设计并制作了用于空间望远镜的新型衍射元件——PI薄膜光子筛。首先，分析了光子筛的设计理论；针对空间应用的特点和原则，采用振幅型光子筛的设计思路给出设计参数；用UG软件设计并加工制作了光子筛的机械固定结构。然后，通过镀膜、光刻、刻蚀等微细加工工艺制作了PI薄膜光子筛。最后，测试了光子筛的衍射效率及成像性能。实验结果表明：光子筛在波长632.8 nm处的实际衍射效率为4.916%，是理论值的73.9%。使用He-Ne激光器，选取10 μm的星点孔进行星点检测，得到了理想的艾里斑图像，其直径为176.70 μm，与理论极限值169.84 μm的误差仅为4.04%。搭建了分辨率板成像实验，测得薄膜光子筛的实际最高分辨频率为12.2 lp/mm，接近理论极限空间频率14.4 lp/mm，表明实验结果与理论分析基本相符。与其它刚性材料基底制成的光子筛相比，采用PI薄膜制作的光子筛不仅重量轻，同时具有较好的成像性能，可以满足空间望远镜主镜的应用要求。

According to the requirements of a space diffraction imaging system for large-aperture, weight-lightening and space deployable, a new diffraction optical element, PI photon sieve, was designed and fabricated. Firstly, the design theory of PI photon sieve was analyzed and the design parameters for an amplitude photon sieve were given according to the characteristics and the principle of space applications. Then, the mechanical structure of the photon sieve was designed by using UG software and a PI membrane photon sieve was successfully manufactured by employing micro-fabrication methods including e-beam vacuum coating, photolithography and wet etching. Finally, the diffraction efficiency of the PI photon sieve was measured and the imaging performance was tested. The experimental results show that the diffraction efficiency of photon sieve is 4.916% at the wavelength of 632.8 nm, which is about 73.9% of the theoretical value. For the star testing, by choosing the star hole with a diameter of 10 μm and using a He-Ne laser for the light source, an ideal Airy disc with a diameter of 176.70 μm was obtained, which is very close to the theoretical value, and the error is only 4.04%. For the imaging experiments, the maximum resolution of the photon sieve is measured to be 12.2 lp/mm,which is close to the spatial frequency limit of 14.4 lp/mm. It is shown that the experimental results are generally in agreement with the theoretical results. Comparing with other diffractive elements, PI photon sieve satisfies the application requirement of the primary mirror used in a space telescope for its lighter weight and better imaging performance .