High sensitivity waveguide grating sensor based on radiative losses.
A scheme of a waveguide sensor utilizing an output grating coupler with the grating length less than the coupling length is analyzed. This is the new method for the evaluation of average thickness of the adsorbed layer. This method, based on measurements of radiation loss coefficients, is proposed. Sensitivity limits of such a scheme are discussed. The new scheme has strong response on formation on the adsorbed layer and relatively weaker response on the fluctuations of temperature and analyte concentration. New possibilities for multiparameter sensing are shown.
Biosensing Techniques↗