Investigation of optical and nonlinear optical properties of DGEBA/IPD epoxy systems under continuous-wave laser irradiation

In this study, two types of epoxy networks based on diglycidyl ether of bisphenol A (DGEBA) were prepared using 4,4′-diaminodiphenyl sulfone (DDS) and isophorone diamine (IPD) as curing agents. The modified epoxy networks were subjected to thermal treatment to improve their hardness and structural integrity. Various characterization techniques, including absorption spectroscopy, photoluminescence (PL), infrared spectroscopy (IR), open-aperture Z-scan measurements, field emission scanning electron microscopy (FE-SEM), and X-ray diffraction (XRD), were employed to evaluate the effects of GO-NH incorporation. Open aperture Z-scan experiment was carried out using a violet semiconductor laser with continues wave (CW) beam and the wavelength of 405 nm. Also, the incorporation of piperazine-functionalized graphene oxide (GO-NH) at 0.5 wt% into the DGEBA/IPD system was investigated in order to study the effect of GO-NH on optical properties. The results showed that reverse saturable absorption (RSA) is the dominant nonlinear optical mechanism in the systems. DGEBA/DDS shows stronger RSA in comparison of DGEBA/IPD system. Notably, the addition of GO-NH led to a significant increase in the nonlinear absorption of DGEBA/IPD, indicating enhanced polarization and improved electronic interactions within the epoxy matrix. These findings suggest epoxy systems as suitable materials in optical and photonic applications.