Phase interrogation surface plasmon resonance (SPR) imaging is, in principle, suitable in multiple samples and high-throughput detection, but the refractive index difference of various samples can be largely varied, while the dynamic range of phase interrogation SPR is narrow. So it is difficult to perform multi-sample detection in phase interrogation mode. In this paper, we successfully designed a multi-channel phase interrogation detection SPR imaging sensing scheme based on a common optical interference path between p- and s-polarized light without using any mechanical moving components. The fixed optical path difference between p- and s-polarized light is introduced by a birefringence crystal to produce sinusoidal spectral interference fringes. We adopted a time-division-multiplexing peak-finding algorithm to track the resonance wavelength so that the detection range can cover every channel. The phase values which carry the high sensitivity signal of the corresponding samples are calculated by the iterative parameter scanning cross-correlation algorithm.
Bibliographical note© 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement.
Funding: Science, Technology and Innovation Commission of Shenzhen Municipality (JCYJ20180305124754860, JCYJ20200109105608771); Guangdong Science and Technology Department (2021A1515011916); National Natural Science Foundation of China (61775148, 61905145).