Investigating the nonlinear optical response of virgin cherry kernel oil and its application to detecting adulteration

Abstract

The nonlinear optical (NLO) response of materials is the basis for their use in various applications, including optical switching, optical data storage, and optical limiting. Additionally, it can be used as an innovative method of authentication. In this study, the NLO properties of virgin cherry kernel oil (VCKO) were studied through the observation of spatial self-phase modulation (SSPM) diffraction rings using a 532 nm continuous-wave laser beam. Based on the intensity-dependent number of symmetric diffraction rings, the nonlinear refraction coefficient and thermo-optical coefficient of VCKO were estimated to be 3.81×10-6 cm2/W and 5.34×10-4 K-1 , respectively, for the first time according to the authors' knowledge. Furthermore, we employed the SSPM technique for adulteration detection in the VCKO by analyzing its NLO properties. To accomplish this, we prepared different adulterated samples by mixing VCKO with cheaper commercial oils such as virgin sunflower oil (VSFO) and virgin canola oil (VCO) at various concentration ratios. In mixed VCKO samples that were adulterated, the measured NLO parameters were correlated highly with the amount of adulteration. The results confirm the ability of the SSPM technique to determine the degree of adulteration in oil samples by measuring and comparing their NLO properties. In addition, our results indicate that cherry kernel oil can be a viable candidate as a nonlinear medium for optical applications.