Dou Jiazhen, Dai Siqing, Dong Chen, Zhang Jiwei, Di Jianglei, Zhao Jianlin
Opt Lett. 2021 Apr 1;46(7):1604-1607. doi: 10.1364/OL.419337.
Surface plasmon resonance holographic microscopy (SPRHM), combining digital holographic microscopy with surface plasmon resonance (SPR), can simultaneously obtain the amplitude and phase distributions of the reflected beam carrying specimen information in SPR. Due to the decaying length of the surface plasmon wave as large as tens of micrometers, the spatial resolution of SPRHM is lower than that of ordinary optical microscopes. In this work, we propose a scheme to improve the spatial resolution of SPRHM by applying dual-channel SPR excitations. Through the polarization multiplexing technique, two holograms carrying the information of SPR excited in orthogonal directions are simultaneously acquired. Via a numerical reconstruction and filtering algorithm for holograms, the lateral spatial resolution of SPRHM can be effectively enhanced to reach nearly 1 µm at a wavelength of 632.8 nm. This is comparable to the resolution of traditional optical microscopes, while possessing the advantages of wide-field imaging and high measurement sensitivity of SPR.
表面等离子体共振全息显微镜（SPRHM）将数字全息显微镜与表面等离子体共振（SPR）相结合，能够同时获取表面等离子体共振中携带样品信息的反射光束的振幅和相位分布。由于表面等离子体波的衰减长度可达数十微米，SPRHM的空间分辨率低于普通光学显微镜。在这项工作中，我们提出了一种通过应用双通道表面等离子体共振激发来提高SPRHM空间分辨率的方案。通过偏振复用技术，同时获取在正交方向激发的携带表面等离子体共振信息的两个全息图。通过一种用于全息图的数值重建和滤波算法，在波长为632.8nm时，SPRHM的横向空间分辨率可有效提高至接近1μm。这与传统光学显微镜的分辨率相当，同时具备宽场成像的优势以及表面等离子体共振的高测量灵敏度。
