LASER-INDUCED FLUORESCENCE DETECTION OF NH3 IN FLAMES WITH THE USE OF 2-PHOTON EXCITATION

Laser-Induced Fluorescence (LIF) has been used for the detection of ammonia molecules, NH3, in flames at atmospheric pressure. Excitation was accomplished by a two-photon step from the ground state, X, to the C′ state, with the detection of the fluorescence radiation from the C′ state to the A state. This excitation scheme was also utilized for the simultaneous flame detection of OH and NH3. NO could also be simultaneously detected with the laser beam resulting from frequency mixing of the IR beam and the doubled dye laser beam from a Nd:YAG-based laser system.