Fig. 4

Angular interrogation sensing results. a, b The angular interrogation sensing steps. Step 1: Define the \({\lambda }_{{SLR}}\) at \({\theta }_{i}=\)0° as the measurement wavelength \({\lambda }_{0}\); Step 2: Scan the \({\lambda }_{0}\) to catch the \({\theta }_{{SLR}}\). c, d Experimental and simulated reflectivity spectra of the 1% glucose solution at different \({\theta }_{{SLR}}\). The difference between both reflectivity trends is from the different \({\theta }_{{SLR}}\) and the influence of measured and fabricated errors. But both reflectivity values reduce first and increase later near the \({\theta }_{{SLR}}\). e, f The SLR angles and angular sensitivities of different solutions from measurement, simulation, and theory derivation. Detail reflectivity-\({\theta }_{{SLR}}\) plots can be found in Note 4, Supplementary Materials