Simultaneous amplitude-contrast and phase-contrast surface plasmon resonance imaging by use of digital holography

Abstract

The surface plasmon resonance imaging technique provides a tool that allows high-throughput analysis and real-time kinetic measurement. A simultaneous amplitude-contrast and phase-contrast surface plasmon resonance imaging method is presented. The amplitude-contrast and phase-contrast images are simultaneously obtained by use of digital holography. The detection sensitivity of amplitude-contrast imaging and phase-contrast imaging can compensate for each other. Thus, the detectable sample components may cover a wider range of refractive index values for the simultaneous amplitude-contrast and phase-contrast imaging method than for the phase-contrast imaging method or amplitude-contrast imaging method. A detailed description of the theory and an experiment of monitoring the evaporation process of a drop of NaCl injection in real time are presented. In addition, the amplitude-contrast image has less coherent noise by digital holography.

Sb2Te3 topological insulator: surface plasmon resonance and application in refractive index monitoring

“…The SPR response is capable of particular applications in refractive index sensing, monitoring and measurement due to the high surface sensitivity. [56][57][58][59] However, the traditional SPR in Kretschmann configurations suffers from the large incident angle, resulting in the limited testing range for specimens. The Sb2Te3-based SPR could offer a feasible avenue to solve this problem and facilitate the detection of environmental refractive index with a smaller angle or broader measuring range (Supporting Information).…”

“…[58] Fortunately, DH can simultaneously provide the intensity and phase information of the specimens with the advantages of dynamic and non-intrusive measurement. [59,67] The SPR-based DH enables to measure the near-field refractive index distribution of the specimen from the hologram recorded in the far field. [59] In DH, the intensity and phase information of the tested specimen are obtained with the angular spectrum reconstruction method (Supporting Information).…”

“…This angle is much smaller than the internal SPR angle of ~70 o in the gold-based Kretschmann configurations, contributing to the reduction of distortion for holographic images. [59,67] The SPR angle sensitivity can be defined…”

“…In the monitoring process, the phase sensitivity is lowest at the time of 501 s, which can be compensated by the highest intensity sensitivity. [59] The phase…”

Surface Plasmon Resonance Imaging by Holographic Enhanced Mapping

“…Recently, in order to exploit this complementary nature of amplitude and phase contrast methods, the possibility of simultaneous measurements of amplitude and phase contrast SPR images using digital holography (DH) was demonstrated. 13 DH in microscope configuration is already used for imaging microstructures and biological systems because of its excellent approach in obtaining intensity and quantitative phase information on a light-wave, 14−19 and prism-based configurations have been used to easily combine DH with total internal reflection (TIR) and SPRi. 20−22 Unfortunately, the physical constraint of the prism limits both the numerical aperture (NA) and magnification of an imaging system.…”