Surface plasmon resonance microscopy (SPRM) is an emerging tool for nanoscale observation. However, while employing the SPRM to observe long-term dynamic processes on the nanoscale, the micrometer-scale optomechanical drift-induced defocus is the main obstacle. This paper proposes a focus drift correction (FDC) enhanced SPRM that calculates the positional deviations of inherent reflection spots to correct defocus displacement without relying on an extra optical system or special imaging pattern, enabling universally applicable nanoscale continuous observation. With the FDC relationships we first revealed, we developed a close-looped SPRM system with focus accuracy reaching 15 nm/pixel and applied the proposed approach to statically and dynamically observe single nanoparticles. The results showed that the SPRM combined with our FDC approach can not only visually distinguish two types of nanoparticles with the sizes of 50 and 100 nm but also distinguish the two types of 100 nm nanoparticles with different materials. These findings indicate that the FDC approach by reflection-based positional detection would provide fundamental support for improving the accuracy and consistency of the SPRM and expand its application for long-term nanoscale monitoring.

中文翻译：

---

通过基于反射的位置检测进行焦点漂移校正增强型表面等离子体共振显微镜


表面等离子体共振显微镜（SPRM）是一种新兴的纳米级观察工具。然而，在利用SPRM观察纳米尺度的长期动态过程时，微米级光机械漂移引起的散焦是主要障碍。本文提出了一种焦点漂移校正（FDC）增强型SPRM，可以计算固有反射点的位置偏差来校正散焦位移，而无需依赖额外的光学系统或特殊的成像模式，从而实现普遍适用的纳米级连续观察。利用我们首次揭示的 FDC 关系，我们开发了一种闭环 SPRM 系统，聚焦精度达到 15 nm/像素，并应用所提出的方法来静态和动态观察单个纳米颗粒。结果表明，SPRM 与我们的 FDC 方法相结合不仅可以在视觉上区分尺寸为 50 和 100 nm 的两种纳米颗粒，而且可以区分不同材料的两种类型的 100 nm 纳米颗粒。这些发现表明，基于反射的位置检测的FDC方法将为提高SPRM的准确性和一致性提供基础支持，并扩展其在长期纳米级监测中的应用。