A– X(0,1) excitation is a promising new approach for NO laser-induced fluorescence (LIF) diagnostics at elevated pressures and temperatures. We present what to our knowledge are the first detailed spectroscopic investigations within this excitation band using wavelength-resolved LIF measurements in premixed methane/air flames at pressures between 1 and 60 bar and a range of fuel/air ratios. Interference from O2 LIF is a significant problem in lean flames for NO LIF measurements, and pressure broadening and quenching lead to increased interference with increased pressure. Three different excitation schemes are identified that maximize NO/O2 LIF signal ratios, thereby minimizing the O2 interference. The NO LIF signal strength, interference by hot molecular oxygen, and temperature dependence of the three schemes are investigated.
© 2003 Optical Society of America
Wolfgang G. Bessler, Christof Schulz, Tonghun Lee, Jay B. Jeffries, and Ronald K. Hanson, "Strategies for Laser-Induced Fluorescence Detection of Nitric Oxide in High-Pressure Flames. II. A–X(0, 1) Excitation," Appl. Opt. 42, 2031-2042 (2003)