Gases that are capable of absorbing and emitting infrared radiation due to their molecular structure are known as infrared active gases. Infrared activity is the underlying reason for the greenhouse effect. Hence, greenhouse gases are all infrared active. The vibrational/rotational structure that makes the molecule infrared active, also causes the energy exchange and the corresponding wavelength shift during Raman scattering.
In this work, Raman scattering spectrum and infrared emission intensity in CO2-containing atmospheric jets at various temperatures and concentrations were measured. The results show that there is a linear relationship between Raman scattering intensity and infrared emission intensity. The linear relationship between Raman signal and infrared emission intensity indicates that Raman scattering can be used as a strong technique for measurement of greenhouse gases
