Investigation of nitrogen plasma effect on the nonlinear optical properties of PMMA
الموضوعات : Journal of Theoretical and Applied PhysicsDavoud Dorranian 1 , Yasaman Golian 2 , Alireza Hojabri 3
1 - Physics Department, Karaj Branch, Islamic Azad University
2 - Physics Department, Karaj Branch, Islamic Azad University
3 - Physics Department, Karaj Branch, Islamic Azad University
الکلمات المفتاحية: Nonlinear optics, Refractive index, Nonlinear absorption, Z, scan, Beam broadening, Two, photon absorption, Optical bleaching, plasma,
ملخص المقالة :
Abstract Effects of low power direct current nitrogen plasma on linear and nonlinear optical properties of red BS dye-doped poly(methyl methacrylate) (PMMA) film are studied employing different optical techniques. From spectrometry data, it is shown that applying plasma in such a low range of power does not affect the linear absorption coefficient, linear refractive index, and optical bandgap of this dye-doped polymer; however, nonlinear parameters are changed. Experiments are performed using the second harmonic of a continuous Nd-Yag laser beam at a 532-nm wavelength and 20-mW power. The effect of nonlinear refractive index of red BS dye-doped PMMA film in broadening the laser beam is observed. The optical bleaching behavior is investigated by measurement of the intensity of laser beam through the sample. Its third-order nonlinearity is measured using close and open Z-scan data. Nonlinear absorption coefficient and refractive index, as well as real and imaginary parts of the third-order nonlinear optical susceptibility χ3, are changed significantly due to plasma treatment. PACS: 42.65.-k: 42.65.An: 42.70.Jk: 61.41. + e: 71.35.Cc.
