Refractive index measurement using free space optic sensing

Abstract

Measurement of refractive index using Free Space Optic is a new approach. Basically, measurement of the refractive index of liquid was being used in communication world, where it is consist of transmitter and receiver. The transmitter will sent data through laser beam to the receiver. However, in this project, the FSO laser beam is being used to measure the refractive index of liquids. FSO consist of transmitter and receiver lens, then in between of the transmitter and receiver lens, a beaker contain a liquid will be placed. From that, the receiver lens which connected to the power meter will display the power value of the liquids. This will continue with a several liquids such as mineral water, cooking oil, river water, vinegar and Clorox bleach. In this project there will be three different of wavelength being used which are 780nm, 830nm and 850nm. After the result was taken, a graph power versus refractive index has been plotted for the each of the wavelength. The power gets for mineral water= -5.116dB, cooking oil = - 5.430dB, river water = -4.521dB, vinegar = -5.670dB, and Clorox bleach = -4.730dB. From all the data, the graph model of refractive index versus power has been plotted.