Fig. 2.

(a) Simulation analysis of the interferometer in Fig. 1 when ε′ changes by 0.005% while tanδ = 0.0975. (b) Simulated and measured results of glucose–water mixture with glucose concentration at 0.1 mol/L. To test measurement repeatability, i.e., to obtain the error bar in (b), inset, multiple measurements are conducted. In each group, we first use DI water as MUT and tune |S₂₁|_min to a given point. Then glucose–water solution is measured to obtain sensor responses.