Investigation of thermally induced nonlinear optical response of polyurethane-graphene composite by SSPM method

Abstract

We conducted a study on composites made of polyurethane and graphene (PU-G). We synthesized these composites and then examined their far-field diffraction patterns at various concentrations of dimethylformamide (DMF) using the spatial self-phase modulation (SSPM) method. By analyzing the intensity-dependent far-field ring patterns, we were able to estimate the samples' thermally induced nonlinear refractive index and thermo-optical coefficient. We found that these variables, as well as other observable phenomena such as the “diffraction ring collapse effect” and “variation in nonlinear refractive index,” depended on the sample's concentration rate. Our results indicate that the laser-induced thermal effect is a significant factor in the SSPM phenomena observed in our experiments. Furthermore, our findings suggest that the PU/G combination in DMF has promising nonlinear optical properties that could be beneficial in a variety of nonlinear optics applications.