Fluorescence emission induced by the femtosecond filament transmitting through the butane/air flame

We measure the backward fluorescence spectra generated by the femtosecond filament transmitting through the butane/air flame, and study the fluorescence emission from combustion intermediates (CN, CH and C-2 radicals), air (mainly N-2 and N-2(+). It is found that the fluorescence emission from combustion intermediates, N2 and NZ shows difference when the femtosecond filament transmits through different parts of the butane/air flame, and we attempt to analyze it in this paper. This study demonstrates that the filament-induced fluorescence technique can be utilized to sense the combustion intermediates. (C) 2017 Elsevier B.V. All rights reserved.