Abstract
The structural and optical properties of the neutron irradiated PMMA doped by 5 wt% RhB have been investigated. Fourier transform infrared analysis showed a significant variation in the polymer’s main chain. Moreover, the linear and nonlinear optical properties of the doped samples, both pre and post irradiation were studied. The results showed that the refractive indices and energy gaps of the examined samples were increased at a neutron dose of 1.5 kGy by about 8% and 7%, respectively. The results gave a good indication in predicting the gain degradation of the polymer optical amplifier when exposed to a low dose irradiation.