The influence of the rectangular dielectric grating filling factor on the grating-based sensor’s sensitive element characteristics

Abstract

The influence of grating filling factor on the spectral sensitivity of sensors, characterized by full width at half maximum (FWHM) and a figure of merit (FOM), operating on the principle of waveguide mode resonance in dielectric gratings formed on a substrate, has been investigated. Resonant wavelengths were determined for varying grating thicknesses and filling factors. Sensitivity values were obtained for normally and obliquely incident plane waves, as well as for Gaussian beams. Additionally, a scaling rule is presented, allowing determination of sensor parameters using a calculator based on identical grating parameters and corresponding resonant wavelengths. This method holds when linear dimensions of the grating and tested wavelengths are scaled proportionally.

Keywords:

• diffraction dielectric grating
• filling factor
• finite cross-section beam
• RCWA
• resonance
• scaling factor

Acknowledgments

The authors express their gratitude to the Ministry of Education and Science of Ukraine for the financial support of this research (project «Development of plasmonic nanostructured substrates for SERS signal enhancement in the detection of explosives» № 0124U000823) and European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie Grant agreement no 823720.

Disclosure statement

The authors declare no conflicts of interest.

Additional information

Funding

The authors express their gratitude to the Ministry of Education and Science of Ukraine for the financial support of this research (project «Development of plasmonic nanostructured substrates for SERS signal enhancement in the detection of explosives» № 0124U000823) and European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie Grant agreement no 823720.