Multi-wavelength selective IR emission using surface plasmon polariton for CO2 gas sensing

Multi-wavelength selective IR emission using reflection type gratings is proposed. Surface plasmon polariton (SPP) is excited by IR having the wavelength nearly equals to the grating pitch. SPP carries IR energy from the thermal source to the outside. The grating element with two different pitches is combined with a thermal source. Emission peaks at wavelengths corresponding to the pitches are confirmed. CO₂ gas is confirmed to absorb the output IR at the wavelength of an emission peak.