Mid-infrared optical sensing using sub-wavelength gratings
| Autor: | Stephen P. Hegarty, Brian Hogan, Michael A. P. McAuliffe, Liam Lewis |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Materials science
Refractive index Physics::Optics 02 engineering and technology Grating Reflectivity Total internal reflection 01 natural sciences Rigorous coupled wave analysis 010309 optics Optics 0103 physical sciences Absorption (electromagnetic radiation) Rigorous coupled-wave analysis business.industry 021001 nanoscience & nanotechnology Extinction coefficients Atomic and Molecular Physics and Optics Surface wave Absorption band Sensor performance Photonics 0210 nano-technology business |
| Zdroj: | Optics express. 27(3) |
| ISSN: | 1094-4087 |
| Popis: | Optical sensing has shown great potential for both quantitative and qualitative analysis of compounds. In particular sensors which are capable of detecting changes in refractive index at a surface as well as in bulk material have received much attention. Much of the recent research has focused on developing technologies that enable such sensors to be deployed in an integrated photonic device. In this work we demonstrate experimentally, using a sub-wavelength grating the detection of ethanol in aqueous solution by interrogating its large absorption band at 9.54 μm. Theoretical investigation of the operating principle of our grating sensor shows that in general, as the total field interacting with the analyte is increased, the corresponding absorption is also increased. We also theoretically demonstrate how sub-wavelength gratings can detect changes in the real part of the refractive index, similar to conventional refractive index (RI) sensors. |
| Databáze: | OpenAIRE |
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