基于全量子理论对相干反斯托克斯拉曼散射(CARS)过程进行了分析,在此基础上搭建了单频CARS显微成像系统,获得了不同尺寸聚苯乙烯微球高对比度的CARS显微图像.为了标定成像系统的空间分辨率,采用逐点扫描方式对直径为110 nm聚苯乙烯微球成像,从而重构出系统的点扩展函数.结果表明:该CARS显微成像系统的横向空间分辨率约为600 nm,而由阿贝衍射极限决定的理论空间分辨率约为300 nm.分析了导致分辨率降低的原因,并提出了解决方案.为实现纳米分辨的CARS显微成像打下了坚实的基础。
In this paper, we analyze the process of coherent anti-Stokes Raman scattering(CARS) based on quantum theory and set up a traditional point-scanning CARS microscope. With this microscope, high-contrast images of polystyrene microspheres are obtained. By scanning polystyrene beads with 110 nm diameter, we reconstruct the point spread faction(PSF) of the system. And the full width at half maximum of the PSF shows a lateral resolution about 600 nm, which is larger than the theoretical value(-300 nm). Therefore, we propose several resolution-improvement approaches, which lay a strong foundation for the realization of nano-CARS microscopy.