Detection of nitric oxide at low ppbm concentrations by differential absorption spectrometry using a fully diode-laser-based ultraviolet laser system

作者：Shao Jie; Lathdavong Lemthong; Thavixay Phaythoune; Axner Ove^*

来源：Journal of the Optical Society of America B-Optical Physics, 2007, 24(9): 2294-2306.

DOI：10.1364/JOSAB.24.002294

• Collision broadening
• Ultraviolet laser system

An instrumentation for detection of nitric oxide (NO) by direct absorption spectrometry in the parts in 109 (ppb) range on its electronic X2II(v′=0)-A2Σ+ (v′=0) transition has been constructed around a commercially available fully diode-laser-based laser system producing milliwatts powers of ultraviolet light at ∼226.6 nm, and its analytical performance has been evaluated. It is shown that the system is capable of detecting NO down to 3 ppb*m under low-pressure conditions (at a signal-to-noise ratio of 3 for a signal averaging of 5 s), which is 2 orders of magnitude below that of any other diode-laser-based absorption technique. The combined line strength of the targeted lines was assessed to 3.1 × 1013 cm-1/(molecule cm-2), which supersedes typical line strengths of the fundamental vibrational band and the first and second overtone bands of NO by ∼2, ∼4, and ∼5 orders of magnitude, respectively. Also the collision broadening and shift of the targeted lines in NO by N2 have been assessed.

• 出版日期2007