Electro-optic dual-comb spectrometer in the thulium amplification band for gas sensing applications

We demonstrate a dual-comb spectrometer based on the direct electro-optic modulation of a continuous-wave laser operating in the thulium amplification band. We show that the emergent two-micrometer technology is already suitable for developing all-fibered dual-comb setups employed here for gas sensing applications. By performing spectroscopic measurements around two micrometers on carbon dioxide, we obtain very good agreement between the experimental results and calculations provided by the HITRAN database. These results pave the way to the extension of electro-optic dual-comb spectrometry in the mid-infrared region.