Observation of nitrogen molecule produced in microwave-discharged flow of nitric oxide by coherent anti-stokes raman spectroscopy

Production of nitrogen molecules in microwave-discharged flow of nitric oxide (NO) was observed by Coherent Anti-Stokes Raman Spectroscopy (CARS). The collinear CARS configuration was chosen to achieve high signal strength under reduced pressure ranging 10-47 torr. The CARS signal for the discharged flow was compared with that for nitrogen flow used, as a reference, in the same pressure range. The signal intensity obtained in both cases increased with increasing pressure. In the discharged NO flow, however, the enhancement was weaker than in the reference flow, indicating the lowering of NO dissociation. In addition, the emission from nitrogen molecule in the discharged flow of NO was observed under the same pressure range. The production of the nitrogen molecule is discussed by comparing the CARS with emission