Laser spectroscopy of deuterated methane at 1.54 μm as a reference standard for optical communications

In this paper we present the first laser-spectroscopy measurements on CH₃D molecules at 1.54 μm wavelength. In particular, the Voigt absorption profiles for the R(6) transition at 1543.78 nm were measured by FM spectroscopy and numerical integration of the 1-st derivative signals. From measurements of the collisional broadening contribution at 3 different gas pressures, the collisional broadening coefficient for the 1.54 μm transition was obtained.