FLUORESCENCE OF CaO (B1Π→X1Σ+) IN A LASER-INDUCED PLASMA

Abstract

The scheme of CaO molecular fluorescence in laser-induced plasma involving the transitions between B1Π and X1Σ+ electron states was proposed and implemented. In fluorescence spectra CaO molecular bands were observed at wavelengths of 408.43 (band 0, 1) and 421 nm. The band at 421 nm was assigned to the
 (0, 3) transition using the energies of vibrational levels calculated by molecular constants. Selective excitation of rotational states was demonstrated, which is observed as a shift of the fluorescence intensity maximum in a spectrum with the change of the wavelength of an exciting laser within the vibrational band. The proposed scheme for CaO fluorescence was used in spatially resolved measurements to show the distribution
 of calcium oxide molecules in laser-induced plasma.