表面等离激元干涉快速调控结构光照明超分辨成像的研究

With the rapid development of Biomedical, chemical materials, and nanotechnology, the higher resolution imaging technology are required. Using special azimuthally multiple structured illuminating light sources such as rotable grating for exciting sample fluorescence and by multiple image processing and reconstruction, the structured illuminating microscopy(SIM) can obtain super-resolution image. However, currently the temporal and spatial resoultion of variant SIM system are still limited and need to be improved for various factors such as the period of the grating, rotation speed, the multiple image processing and reconstruction. In this project, a pure phase spatial light modultor is adopted to generate lateral multifocal spots which are controllable in terms of position, phase, polarization and numbers. A fast rotatable surface plasmonic interference fring as structured illuminating sources for exciting sample fluoresence can be formed when a microstructure milled on the expensive metal film is excited by a pair of rotatable focal spots. Accordingly, an image with resolution of 100 nm can be obtained through image processing. Further, we will quantatively and directionally translate the sample on the microstructure in nanometer scale and repeat the above described SIM procedures multiple times to obtain several images with resolution of 100 nm . Finally we expect to create a sample image with resolution of around 20 nm through fine difference comparison of several images, position recovery and image reconstruction.

生物医学、化学材料和纳米技术的快速发展，对超高分辨率成像技术提出了越来越高的要求。结构照明超分辨显微利用特殊结构光源照明样品，使得代表图像细节的高频成份信息能够通过物镜成像，并通过图像处理技术获得特殊结构对应的超分辨图像。在现有各种改进的结构照明显微技术中，由于结构照明空间周期、光栅旋转和多幅图像处理等因素仍然限制了显微成像的时间分辨率和空间分辨率。本项目拟采用纯相位空间光调制器实现偏振可控横向双焦点激发贵金属表面微结构，从而形成表面等离激元干涉条纹照明样品；再通过快速更新位相调制实现不同方向的干涉条纹结构照明的快速调控，从而快速获得100纳米左右分辨率的样品图像；进一步通过定量和定向纳米位移，多次错开样品实现多次结构照明超高分辨率成像；最后将具有细微差异的多幅超高分辨率图像进行位置复原并合成一幅分辨率20纳米左右的超高分辨率显微图像。项目的研究将推动我国超分辨成像技术的发展及相关应用。

国家自然科学基金项目“表面等离激元干涉快速调控结构光照明超分辨成像的研究”(61775140)2018年1月实施，2021年12月完成。 .表面等离激元(SPPs)是一种沿金属/介质界面传播的表面波，具有波长小于激发光波长、场增强、对介质折射率变化敏感等特点。表面等离激元结构光照明显微成像技术是一种新型的超分辨成像技术，具有超分辨、快速、光场等特点。本项目对表面等离激元结构光照明显微成像技术的理论和实验方面进行了深入和卓有成效的研究。 .1.发表SCI论文47篇；.2.获得授权发明专利4项； .3.通过理论模型和实验实现了空间位置、相位、偏振、数量等多参量均可控的多焦斑；.4.实现了微纳光栅微参数优化和加工；.5.通过光学平台实现了表面等离激元的激发； .6.通过模拟对表面等离激元的激发和光场进行了优化和调控； .7.将表面等离激元的调控机理应用到多个相关领域。