Educational opto-mechatronic apparatus to calculate the refractive index of liquids based on Snell's Law Academic Article in Scopus uri icon


  • © 2019 SPIE, ICO, IEEE, OSA.This work presents a simple, low-cost opto-mechatronic educational device that determines the refractive index for liquids, which is performed automatically on the computer with an Arduino UNO card through a LabVIEW graphical interface. The operation of the apparatus is based on passing a laser beam through a container with the given substance; then, the refracted beam will be detected with a photoresistor which is moved along the axis by a stepper motor. The distance traveled by the motor until the beam of light impinges on the photoresistor together with known constants (distances between the fixed elements, thickness of the container and refractive index of this material) will be used to calculate the refracted angle through the unknown medium, as well as its refractive index, by linking all the variables in a formula derived from Snell's Law.

Publication date

  • January 1, 2019