Self-induced pressure shift and temperature dependence measurements of CO2 at 2.05 μm with a tunable diode laser spectrometer

By using a high resolution tunable diode laser absorption spectrometer combined with a cryogenically cooled optical multi-pass cell, we have measured the self-induced pressure shift coefficients for 8 transitions in the R branch of the (2001)III ← (0000)I band of carbon dioxide around 2.05 μm. This spectral region is of particular interest for the monitoring of atmospheric CO2 with Differential Absorption Lidars (DiAL). The measurement of these shift coefficients was realized at five different temperatures ranging from 218 to 292 K in order to determine their temperature dependence. The results are thoroughly compared to previous values reported in the literature for the (2001)III ← (0000)I band of CO2. The temperature dependence of the self-induced pressure shifts are reported experimentally for the first time for this specific CO2 band.

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► We report on self-shift coefficients for 8 absorption lines of CO2 at 2.05 μm.
► A high-resolution TDLAS coupled to a cryogenically cooled cell was used.
► Temperature-dependencies of the self-shift coefficients are also determined.
► These parameters are carefully compared with results in other vibrational bands.