Malus' Law. The results should show a cosine squared dependence of the transmitted intensity on the angle, validating the theoretical predictions and enhancing our understanding of polarized light. This setup can be used in undergraduate physics labs to demonstrate the principles of light polarization and the behavior of light passing through polarizers. Malus Law Apparatus dedicated to elucidate students to understand the wave nature of light. Diode Laser is used as a source of unpolarized light. With the help of this apparatus the basic law of polarization and Malus law experiment can be verified. Polarization can be studied by direct vision as well as by reading the variation of intensity through a digital ammeter connected across a photodetector.