Tontarawongsa Sorawit, Visitsattapongse Sarinporn, Pechprasarn Suejit
Department of Biomedical Engineering, School of Engineering, King Mongkut's Institute of Technology, Ladkrabang, Bangkok 10520, Thailand.
College of Biomedical Engineering, Rangsit University, Pathum Thani 12000, Thailand.
Biomed Opt Express. 2021 Dec 24;13(1):485-501. doi: 10.1364/BOE.448085. eCollection 2022 Jan 1.
Here, we apply rigorous coupled-wave theory to analyze the optical phase imaging performance of scanning confocal surface plasmon microscope. The scanning confocal surface plasmon resonance microscope is an embedded interferometric microscope interfering between two integrated optical beams. One beam is provided by the central part around the normal incident angle of the back focal plane, and the other beam is the incident angles beyond the critical angle, exciting the surface plasmon. Furthermore, the two beams can form an interference signal inside a confocal pinhole in the image plane, which provides a well-defined path for the surface plasmon propagation. The scanning confocal surface plasmon resonance microscope operates by scanning the sample along the optical axis z, so-called V(z). The study investigates two imaging modes: non-quantitative imaging and quantitative imaging modes. We also propose a theoretical framework to analyze the scanning confocal surface plasmon resonance microscope compared to non-interferometric surface plasmon microscopes and quantify quantitative performance parameters including spatial resolution and optical contrast for non-quantitative imaging; sensitivity and crosstalk for quantitative imaging. The scanning confocal SPR microscope can provide a higher spatial resolution, better sensitivity, and lower crosstalk measurement. The confocal SPR microscope configuration is a strong candidate for high throughput measurements since it requires a smaller sensing channel than the other SPR microscopes.
在此，我们应用严格耦合波理论来分析扫描共焦表面等离子体显微镜的光学相位成像性能。扫描共焦表面等离子体共振显微镜是一种嵌入式干涉显微镜，它在两束集成光束之间产生干涉。一束光由后焦平面法向入射角附近的中心部分提供，另一束光是超过临界角的入射角，用于激发表面等离子体。此外，这两束光可以在像平面的共焦针孔内形成干涉信号，这为表面等离子体传播提供了明确的路径。扫描共焦表面等离子体共振显微镜通过沿光轴z扫描样品来操作，即所谓的V(z)。该研究调查了两种成像模式：非定量成像和定量成像模式。我们还提出了一个理论框架，用于将扫描共焦表面等离子体共振显微镜与非干涉表面等离子体显微镜进行比较，并量化非定量成像的空间分辨率和光学对比度等定量性能参数；以及定量成像的灵敏度和串扰。扫描共焦表面等离子体共振显微镜可以提供更高的空间分辨率、更好的灵敏度和更低的串扰测量。共焦表面等离子体共振显微镜配置是高通量测量的有力候选者，因为它比其他表面等离子体共振显微镜需要更小的传感通道。
