Spectral, morphological and third-order nonlinear optical properties of reduced graphene oxide

This study presents the synthesis, structural, spectral, linear and third-order nonlinear optical (NLO) properties of reduced graphene oxide (rGO). The rGO was synthesised using a modified Hummers method and subsequently characterised through UV–visible spectroscopy, FT-IR, Raman spectroscopy, and X-ray diffraction. The morphology of the synthesised rGO was examined using FESEM, while the elemental composition of the sample was analysed using EDX spectroscopy. The NLO properties of rGO were investigated using the Z-scan technique at a wavelength of 405 nm under a low-power regime. The OA and CA Z-scan measurements reveal saturable absorption behaviour and a self-defocusing nonlinear refractive index. The nonlinear absorption coefficient and nonlinear refractive index of rGO were determined to be − 1.32 × 10−2 cm/W and −2.01 × 10−7 cm2/W, respectively. These findings provide valuable insight into the optical behaviour of rGO, highlighting its potential as a promising material for future photonic and optoelectronic applications.