

In this research the optical properties for pure PVA and PVA-Methylene blue (MB) films in different doping ratio that prepared by using casting method was been studied. The absorption and transmission spectra were measured by UV-Visible spectrophotometer. The optical energy gap was indirect transition for pure PVA film about 5.15eV for allowed and 5.17eV for forbidden. These energies were decreased with increasing doping ratio of MB contents to become 4.88eV and 4.85eV for allowed and forbidden, respectively. Whereas energy gap for Methylene blue in chloroform solution was 1.78 eV and 1.88 eV for allowed and forbidden indirect transition, respectively. The value of energy gap became 1.75 eV and 1.78 eV for allowed and forbidden indirect transition after doping with PVA polymer films for all doping ratio of dye solution. Full width half maximum absorption spectrum was calculated for all samples. Also, all optical constants (absorption coefficient, refractive index, extinction coefficient, and complex dielectric constants) were investigated and compared with other researches.