Determination of the Optical Properties of Pure and Doped Polyvinyl Alcohol using Different Lasers

Abstract

In this work, the optical properties of purepolyvinyl alcohol(PVA) and PVA doped with silver nitratewith different mass ratioswere studied using different types of monochromatic light sourcesin wavelength range (360-920) nm. All samples were prepared as disks by pressing the powder using compressor,the fabricated disks with different thicknesses (3.13, 4. 61 , 6. 24 , 7.73 , 9.10 ,10.97) mm for pure PVA, and a disk with a thickness (9.10mm) was chosen and prepared with different ratios of silver nitrate (10,20,30,40,50) % for doped PVA. The incident light intensities were measured in the absence of samples, which regarded as the reference (I_0), then the transmission intensities (I_T) for each sample were measured by placing the monochromatic light source, the detector, and the sample on the same line.The reflected intensities (I_R) also were measured by placing the monochromatic light source and the detector at angle of 450 with the samples. The absorption coefficient for all samplewere calculated using Beer-Lambert law. In addition, the refractive index also was calculated for each sample. The optical properties (absorption coefficient, transmission percentage, and refractive index) of fabricated disks with different thicknesses and different concentration of silver nitrate of pure and doped PVA were plotted as a function of wavelength. The obtained results showed the possibility ofusing pure PVA and doped PVAas an optical filter in certain wavelengths or as reflector for other wavelengths, and there is a changein the optical properties due todoping of PVA by silver nitrate.