Dual-comb spectrometer in the two-micron region using a new design of dispersion-controlled highly nonlinear fibre

We present here an experimental demonstration of dual-comb spectroscopy performed around 2 µm, with the use of a new design of dispersion-controlled highly nonlinear fibre. The latter allows us to efficiently convert light via a four-wave mixing process from 1.55 µm to 2 µm, which is a spectral region suited for the detection of pollutants such as CO2 or N2O. Experimental measurements have been performed with these two molecules and show an excellent agreement with the HITRAN database