We report on absolute line strength measurements of P(1), R(0) and R(1) singlet lines in the 3:3 μm ν3 (C–H stretching) band of methane 12CH4 at referencetemperature T = 296 K. Line strength measurements are performed at low pressure (P <1 Torr) using direct absorption spectroscopy technique based on a widely tunable continuous-wave singly resonant optical parametric oscillator. The 1σ overall accuracy in line strength determinations ranges between 7 and 8 % mostly limited by pressure and frequency measurements. A comparison with previous reported values is made. Our results show good agreement with the HITRAN 2012 database.
Zondy, J-J., de Souza, M. P. M., Cadoret, M., Jahjah, M., Nguyen, L., & Cruz, F. C. (2014). Line intensity measurements of methane’s ν3-band using a cw-OPO. Applied Physics B: Lasers and Optics, 117, 681–687. https://doi.org/0.1007/s00340-014-5883-1