Kr^+ and Ar^+ laser-excited fluorescence of CN in a flame

Laser-excited fluorescence of the CN radical was obtained using various discrete prism selected lines of krypton and argon-ion lasers. The source of hot CN is a slightly rich atmospheric pressure CH4/N2O premixed flame diluted with N2. The flame is placed within the extended cavity of the ion lasers to take advantage of much higher light intensities. Both B2∑+ ← X2∑+ and B2∑+ ← A2Π transitions of CN have been pumped. The Kr+ laser lines, 6764, 6471, 5309, 4680, 4154, 4131, and 3564 Å, all pump CN. The 4545-Å line of the Ar+ laser also pumps CN. Vibrational and rotational assignments have been made. Detection of CN in a burning propellant sample has been accomplished by this technique.