Application of combustion flames for generation of third harmonic and super-hydrophobic coating of glasses by deposited carbon nanoparticle films

We analyzed the third harmonic generation (THG) of 1064 nm, 28 ps radiation in the candle and ethanol flames. The formation of soot nanoparticles in the candle flame led to the increase of third harmonic yield compared to the ethanol flame. 12- and 24-fold enhancement of the third harmonic yield in candle and ethanol flames compared to the THG in air was achieved. The influence of the nonlinear refraction in air and combustion flames on the phase-matching conditions of THG was found responsible for deviation from the cubic I _3ω (I _ω) dependence. THG conversion efficiencies of Nd:YAG laser radiation were found to be 1  ×  10⁻⁵, 1.2  ×  10⁻⁴ and 2.4  ×  10⁻⁴ in the cases of air, carbon flame and ethanol flame media, respectively. Furthermore, the super-hydrophobic properties of the deposited carbon species from the candle flame were demonstrated. (paper)