T-grating on a nano-cavity array based refractive index sensor

We report a refractive index sensor comprising unique T-grating on top of periodic nano-cavities. The has two resonant modes sensitive to different regions the structure with low inter-region interference, hence allowing simultaneous detection analytes or more accurate single analyte. also provides self-referencing feature for broad range indices, from 1.3 1.5. Using finite difference time domain method, sensitivities 801.7 nm R mathvariant="normal">I mathvariant="normal">U − 1 and 1386.8 were recorded modes. versatility makes prominent candidate biochemical other sensing applications.