Third order nonlinear optical properties of DNA-based biopolymers thin films doped with selected natural chromophores

Abstract The results of linear and nonlinear optical (NLO) studies on thin films of DNA based biopolymers, doped with natural chromophores extracts of sweet paprika, turmeric as well as curry leaves are reported and discussed. The thin films were obtained by spin coating on glass substrates. The spectroscopy measurements show that the extracts absorb in visible, at different wavelengths, revealing an important π electron conjugation. The nonlinear optical measurements, done by the optical third harmonic generation technique at 1064.2 nm fundamental wavelength, show that the fast, electronic origin third order NLO susceptibility of natural extracts χ ( 3 ) ( − 3 ω ; ω , ω , ω ) , is large and comparable or higher than that measured for synthetic counterparts. The largest one in this study was found for the curry leaves extract: (396.9 ± 40) ×10 −14  esu.