Abstract
Experimental study on the pulsed-Raman spectroscopy has been performed to measure the Raman scattering cross sections for gaseous molecules, including important air pollutants. The optimum conditions for light collecting ability have been analysed for four different optical systems, and the convex lens system was found to have the highest collecting efficiency for the focused laser beam. Furthermore, the pulse-gate photon counting method has been developed for detecting extremely low-intensity, pulsed light signals. From an analytical study, it is concluded that this method gives better performance as compared with the con-ventional techniques.
The Raman scattering cross sections for 15 gaseous molecules relative to that of N2 have been measured at 3371 Å using a pulsed N2 gas laser. Acceptable agreement, within experi-mental accuracy, exists for our data with previously published data using visible light sources.
