The study and comparison of power-dependent nonlinear optical behaviours of α-mangostin with Sheik-Bahae formalism and thermal lens model using Z-Scan technique

Abstract

The pericarp of Garcinia mangostana (mangosteen) contains α -mangostin (α -MG), which is an essential compound derived from the family of xanthone. This study aimed to determine the nonlinear optical response of the extracted α -MG using Z-scan technique (532 nm, 0.5–1.0 W). A series of characterisations were also done by using 1H &13C nuclear magnetic resonance (NMR), electron impact mass spectrometry (EIMS), ultraviolet-visible (UV–vis) and Fourier transform infrared (FTIR) to validate the identity of the extracted α -MG. The results showed that only nonlinear refraction (NLR) was successfully captured and measured by the closed-aperture signal. The localized absorption across the media enabled the α -MG to exhibit a self-defocusing effect. The recorded values of the nonlinear refractive index, which were denoted as n2, were then compared with two different theoretical fitting curves, which were Sheikh-Bahae Formalism (SBF) and Thermal Lens Model (TLM). The values of n2 obtained were in the order of 10−9 and 10-10 for SBF and TLM, respectively. The NLO characteristics of the α -MG were observed at the excitation wavelength of 532 nm.