In the present work, film samples of pure and doped poly(methylmethacrylate) (PMMA) polymer with different concentrations of Celestin Blue B dye were prepared using casting method. The optical properties of these films were investigated. The optical absorbance and transmittance spectra of the film samples were measured in the UV–Visible wavelength range 300 - 900 nm. From these spectra, the main optical coefficients of these samples, such as, absorption coefficient (α), extinction coefficient (k), refractive index (n), reflectance (R), dielectric constants (the real (ε_r ) and imaginary (ε_i) parts), were determined. The values of band gap energy (E_g) of the samples were also determined. Results indicate that the Celestin Blue B dye is a promising candidate for the photonic device applications.

Keywords: Celestin Blue B Dye; Dye - Doped Polymer Film; Optical Properties; Optical Constants; Band Gap Energy;