Effect of GaAs pulsed laser on the structure and optical characterization of Makrofol VLG 7-1

Abstract

Samples ofMakrofol films were exposed to different laser fluences (2-18 J/cm 2 ). X-ray diffraction (XRD) and ultraviolet spectroscopy (UVs) techniques were used to explore the resultant effect of laser radiation on the structure and optical characteristics of the Makrofol polymer. The change of refractive index (n) and the optical band gap (Eg) with the laser fluence was interpreted. A reduction in the Eg values (3.08-2.54 electron volt) was observed when raising the laser fluence up to 18 J/cm 2 . This was accompanied by an increase in refractive index from 2.376 to 2.533. This was attributed to the prevalence of crosslinking that damaged the crystalline portion in the Makrofol polymer. The crosslinking created color centers that induced differences in color between the exposed films and the uncolored pristine Makrofol film. The color difference was significant as the values of E were greater than 5. This optimized the Makrofol polymer to be used in dosimetric applications.