摘要： Thin films of PMMA doped with Rhodamine B-dye have deposited successfully on a fluorine-doped tin oxide (FTO) glass substrate as a new optical system by using a spin coating method. This new system is promising to be used in various technological applications as solar energy cells, electronic apparatuses, devices of optical filter properties and optoelectronic tools. X-ray diffraction (XRD) illustrates a uniform and semicrystalline structure in nature for the obtained thin films. A spectrophotometric investigation was applied on the prepared thin films at the range of (300–2500 nm) for the wavelength. Both linear refractive index and absorption index values were measured to be reduced as the wavelength was raised. Tauc’s plot indicated that direct and indirect transitions were displayed by the thin film. Both direct and indirect bandgaps were calculated and analyzed. Continuous waves of the green laser beam (operating at 532), and He-Ne laser beam (operating at 632.8 nm) were used to study the optical properties of the prepared thin films with different dye concentrations. The results illustrated that the polymeric composites films are highly attenuated for the laser beam of 532 nm. The designed RhB-doped PMMA/FTO composites can be extensively appropriate to the optoelectronic applications.