Free-radical fluorescence emissions induced by 1,030 nm femtosecond laser filamentation in ethanol flame

We experimentally investigated clean optical emissions from multiple combustion intermediates including free radicals C 2 , CH, and CN at wavelengths induced by ultrashort 1,030-nm laser pulses. systematically study the evolution of fluorescence femtosecond filament in field with parameters such as pulse energy, duration, focal length. Compared previous work, we promote that product can be manipulated effectively controlling characteristics focusing conditions. This process helps to optimize its signal-to-noise ratio, which provides a further application pulses sense intermediates.