Optical lightpipe sensor based on surface plasmon resonance

Abstract

In this paper, a novel optical sensor using surface plasmon resonance in a symmetrical planar lightpipe is introduced. The new design utilizes a microscope slide with beveled ends as the sensor substrate. Collimated TM polarized white light is used to interrogate the sensing surface at a single angle. Preliminary experimental results for glycerol solutions from 0.6%wt to 16%wt demonstrate a concentration sensitivity of 3.4 multiplied by 10-4 by weight. The corresponding refractive index sensitivity is estimated as 4 by 10-5.