Angle dependent wavelength measurement using open spectrophotometer and optical characterization of thin films

In this study, angle dependent optical transmittance measurement system supported by Arduino Uno has been developed to accurately determine the optical constants of thin films. Using this system, the angle of incidence light could be measured with an accuracy of +/- 0.01 degrees and the relative optical transmittance with a precision of 0.01%. By taking into account, the accuracies in the designed system and the wavelength uncertainty of the spectrophotometer (0.15 nm), the factors that may adversely affect the optical transmittance measurements have been eliminated. With this designed system, optical transmittance spectra obtained for two different angles of incidence were obtained precisely for the a-SiNx:H sample prepared using the glow-discharge system. These spectra and the genetic algorithm were used to determine the optical constants of the sample. With this new system, optical constants were determined faster and more accurately (+/- 0.05%) than the classical method. Measurement of the absolute optical transmission is no longer required.