Effect of Laser Treatment on the Optical Properties of Poly(methyl methacrylate) Thin Films

In this work, the effect of laser pulse treatment on the optical properties of poly(methyl methacrylate) (PMMA) films has been studied experimentally. The second harmonic of a pulsed Nd:YAG laser at 532 nm and 6 ns pulse width with 10 Hz repetition rate was used to modify the surface of red-BS-dye-doped PMMA films. Samples were ablated with 50 and 100 laser pulses. Optical reflectance and transmittance spectra were obtained in the range of 200-2000 nm. The optical properties of the films were influenced by the pulse number significantly. The oscillator and dispersion energies of the films were determined using the Wemple-Didomenico model. The optical band gap energy was extracted using the Tauc method. Results show that the optical parameters of the films were changed significantly after laser treatment. (C) 2013 The Japan Society of Applied Physics