Z-scan studies of third-order nonlinear optical and optical limiting properties of chalcones doped Poly(methyl methacrylate) thin films for visible laser protection

In the present study, third-order nonlinear optical properties of three chalcone derivatives, (2E)-3-(4-methoxyphenyl)-1-(4-nitrophenyl)prop-2-en-1-one (MNC), (2E)-3-(4-methylphenyl)-1-(3-nitrophenyl)prop-2-en-1-one (ML3NC) and (2E)-3-(3,4-dimethoxyphenyl)-1-(4-methoxyphenyl)prop-2-en-1-one (DMMC) doped Poly(methyl methacrylate) (PMMA) thin films are reported. The thin films were prepared using spin-coating technique at three different doping concentrations. Surface roughness and linear optical properties of the films were studied by atomic force microscopy (AFM) and UV-Vis-NIR absorption spectrum, respectively. The intermolecular interactions of the chalcones were studied using Hirshfeld surface analyses (HSA). The third-order nonlinear optical (NLO) properties of the films were investigated by using Z-scan technique with DPSS continuous wave (CW) laser excitation at 532 nm. All the films exhibited strong nonlinear absorption (NLA) behavior, and the obtained nonlinear absorption coefficients (β) increases with doping concentration of chalcones. Further, we observed the optical limiting property for all the films, which is mainly originated from two-photon absorption (TPA) mechanism. The calculated third-order nonlinear absorption coefficients (β), imaginary part of third-order nonlinear susceptibilities (Im χ(3)) and the optical limiting (OL) thresholds of the films are in the order of 10−5 cm/W, 10−8 esu and 103 J/cm2, respectively. The results revealed that the chalcones doped PMMA thin films are promising materials for optical limiting applications in visible region.