Plasmonics gas sensor bases on electromagnetic induced transparency (EIT) In MIR

A novel optical gas sensor based on electromagnetically induced transparency (EMT)is proposed. In this paper we propose plasmonic non concentric ring resonators resonate near the absorption regions of many gases in the mid-infrared region. Mid-infrared (MIR) wavelength range is of particular interest because it contains the absorption resonance for several molecules such as methane, carbon dioxide, carbon monoxide, and acetone. The sensing process is controlled by changing the refractive index. The proposed slotted waveguide coupled with double non-concentric ring resonators, both the waveguide and rings are surrounded with doped silicon. Doped silicon can act as a suitable plasmonic alternative instead of metals in the MIR range. When the two coupled non-concentric rings optimize to resonate on the same wavelength; interesting phenomena occurs such as the Fano-resonance and the electromagnetic induced transparency effects. In this paper we show the electromagnetic induced Transparency which is an absence of the resonant spectral lines of the same wavelength, and the creation of two resonance lines at red-shifted and blue-shifted wavelengths. Moreover, we mentioned all the details about the dimensions and the material used for our design. A Small foot print, high sensitivity, and high Figure of merit are achieved.