Spectral normalization in dual-comb spectroscopy of acetylene using a sealed gas cell and a liquid nitrogen trap

Abstract

We demonstrate spectral normalization in dual-comb spectroscopy of acetylene using a sealed gas cell and liquid nitrogen trap. The normalized spectra of the P- and R-branches of the ν 1 + ν 3 vibration band of 12 C 2 H 2 were observed at a comb repetition rate of 19.8 MHz. We also observed instantaneous pressure changes inside the cell during the cooling of the liquid nitrogen trap, with different averaging times.