Abstract
A simple and reliable method of measuring the refractive index of thin film is reported in the present paper. In this work, an experimental approach of Digital Abbe Spectrometer was used for measuring refractive indices of pure and doped PMMA at different wavelengths in the visible region. Refractive indices measurements at wavelengths of 405 ,458, 492.2, 499, 546, 589, 632.8, 659.2, 670.2 nanometres were taken of Titanium di Oxide doped Poly (methyl metha acrylate) PMMA films. Also we explain with the help of graph refractive indices of PMMA increases with increasing doping percentage (0.0001%,0.0005%,0.001%,0.005%,0.01%,0.05%) & we compare the refractive indices of un annealed and annealed polymer of doped PMMA at different temperatures (40°C, 60°C, 80°C, 100°C).