A comparative analysis of power-dependent nonlinear optical traits in unique 'star-type' triphenylmethane chromophores via facile Z-scan measurement

Abstract

This study reports the nonlinear optical (NLO) attributes of both nonlinear refraction (NLR) and nonlinear absorption (NLA) for the “star-type” chromophores known as Malachite green (MG) and Light green SF yellowish (LGSF). In this research, a Z-scan technique was utilized to carry out the nonlinear procedure. The presence of linear absorptions at 532 nm for both chromophores are the prerequisite for the emergence of NLA phenomenon. The vital intermolecular charge transfer of the π-bonds were evidenced by the vibrational bonds of FTIR analysis spectrum for both chromophores. These bonds were responsible for the appearance of the functional attributes of nonlinearities under the utilized laser power, P. The output signals from open and closed-apertures recorded that MG and LGSF chromophores possesses reverse saturable absorption (RSA) and self-defocusing effect (-n2) in the order of 10−4 cmW−1 and 10−9 cm2W−1, respectively. This indicates a good property of nonlinearity to developed into various optical applications.