Determination of the Optical Properties of Fabricated CuSO4 Thin Films

Abstract

In this work, a known concentration of CuSO4 dissolved in distilled water in order to fabricate thin films on glass substrate of (1.5) refractive index and (1.2) mm thickness by evacuation method in the presence of laser source to control the thickness of the deposit film. Two laser types were used in control process, diode laser (532 nm) and He-Ne laser (632.8 nm) . They were selected due to their emissions in the visible region, which aid in alignment between them and the optical detector. According to the relation between the film thickness and the wavelength of the laser, the interference phenomenon in thin films, and for their low powers they were safe to operate with. Two films with different thicknesses were deposited on two glass substrate that have the same refractive index and the same thickness for each film the transmitted intensity in different monochromatic light sources was recorded before the deposition process. Then calculation were carried out for the Transmission percentage, refractive indices and the absorption coefficients.(The transmission percentages were calculated by considering the thin films not absorb any part of the intensity). The relation between percentage transmitted intensity and the wavelength was plotted for each film to represent part of its transmission spectrum, and then the calculated relations (refractive indices and absorption coefficients) were plotted as functions in wavelengths. The same procedure was repeated for each film and the optical properties (transmission spectrum, refractive indices and absorption coefficients) for the two films, the relations of the optical properties was shown to be dependent on the film thickness. The obtained results shows the possibility of the deposit material (thin film of CuSO4 on glass substrate) as an optical filter in certain wavelengths or as reflector for other wavelengths.