Research on absorption spectroscopy of CH₄ around 1.315 μm

Measurements have been made about the absorption features of CH₄ around 1.315 μm by using the second harmonic detection technique of tunable diode laser with multipass cell (white). Studies concerning the second harmonic detection technique of CH₄ around 1.65 μm have been widely reported currently, but reports about the absorption features in NIR spectra of CH₄ around 1.315 μm can scarcely be found. We have performed a detailed study about the absorption features of CH₄ around 1.315 μm and we present the results here. We give the line positions, the line intensities and self-broadening coefficients near 1.315 μm at a pressure of 0.077 torr.