Optical Storage Properties of Novel Azo Dye-in-Polymer (PMMA) Thin Films

Abstract

A new write-once optical recording medium (azo dye-in-poly(methylmethacrylate) film) is reported. Optical and thermal properties of the azo dye and its films are studied. The azo dye prepared has a strong absorption band at 461 nm. The azo dye-in-polymer film made by the spin coating process has a strong and broad absorption band, and the reflectivity is greater than 10% in the visible region, which matches well with the wavelength of the argon-ion laser. The aggregate state of the azo dye molecules greatly influences its absorption spectra. The electronic structure of the film has been explained. The reflectivity contrast of the film is more than 30% at writing power (13.3 mW) and writing pulse width (600 ns) using an argon-ion laser operating at 514.5 nm, and the film has sharp thresholds for optical recording.