高数值孔径下高斯光束超分辨技术

利用矢量衍射理论,研究了高数值孔径下高斯光束的超分辨特性,对可以实现超分辨的二环和三环相位结构进行了优化求解,分析了环带半径和相位变化对超分辨性能的影响规律,给出了优化方法和优化结果.研究结果表明:当和平面波照明具有相同的旁瓣比时,使用高斯光束照明仍然可以实现光学超分辨;采用二环相位结构时,内环半径的控制比较关键,相位的微小改变对超分辨性能的影响不大,二环相位结构具有加工容差大的优点;三环相位结构在相同旁瓣比的情况下能够达到较大的压缩比和较小的主瓣峰值强度,三环结构的半径和相位的改变对超分辨性能的影响较大,其加工容差要小于二环相位结构;无论二环或三环相位结构,若提高压缩比,必然会引起主瓣峰值强度降低和旁瓣比增大.该研究为高数值孔径下,高斯光束照明时,超分辨光瞳滤波器的优化设计提供了一种新方法.

Superresolution Technology of Gaussian Beam under High Numerical Aperture

Using vector diffraction theory, the superresolution properties of Gaussian beam are studied under high numerical aperture. The two and three rings phase structures, which can realize superresolution, are solved and optimized. The varirty regularities of superresolution properities are analyzed with the changing of radius and phase. The methods and solutions of optimization are also given. The results show that superresolution can be get with the same side lobe at illumination of plane wave, when using the Gaussion beam illumination.The inner radius is crucial when using two ring phase structure and the property of superresolution has little change with tiny phase changing. Two ring phase structures have the advantages of machining tolerances. Three ring phase structures can get larger compression radio and small peak intensity of the main lobe with the same side lobe. The changing of radius and phase has important influence on the performance of superresolution. The machining tolerance is smaller than that of two ring phase structure. For both two and three ring phase structure, the increase of compression radio will inevitably cause the decrease of main lobe peak intensity and the increasing of the sidelobe radio. This research provides a new method for the design of superresolution pupil filter with Gaussian beam illumination under high numerical aperture.