Development of Brewster angle measurement instrument using microcontroller unit

− Brewster's angle method is one that commonly used for measuring high index material. This method enables one to measure unlimited range of refractive index. Due to complicated setup of measurement, measurement is commonly carried manually. This paper presents an automatic instrument for measuring Brewster's angle designed using microcontroller unit (MCU) Arduino. Calibration was made by comparing what was measured by this method with that measured using ABBE Refractometer. It was found that both method showed resembling results. The designed instrument is used to measure the value of the refractive index of the Soda-lime planar waveguide, PMMA glass, and Silica glass. From the measurement, it is known that the refractive index value of the three materials are 1.522, 1.463, and 2.055 respectively.