Light, as any other electromagnetic wave, always propagates as a transverse wave, with both electric and magnetic fields oscillating perpendicularly to the direction of propagation. The di rection of the electric field is called the polarization of the wave. In a linearly polarized plane wave the electric field remains in the same direction. This pure state of polarization is called linear polarization. According to Malus’s Law, when completely plane polarized light is incident on the analyzer, the intensity I of the light transmitted by the analyzer is directly proportional to the square of the cosine of angle between the polarization axis of the analyzer and the po larization axis of the polarized light, θ. Magneto-optics relies on change of light polarization or intensity upon interaction with a magnetic sample. It is called the MOKE in the reflection geometry, and Faraday effect in transmission. Depending on the geometry it may be sensitive to magnetization planar and/or perpendicular, with respect to the reflecting/transmitting surface. In this thesis work, we have developed a prototype homemade polarimeter and characterized the linearity of the electromagnetic polarization using three different light sources. We have used white light, laser pointer, and He-Ne laser which emits radiation at a wavelength of 630 nm. The experimental data are fitted according to Malus’s law. We have found that the laser pointer emits light with good polarization quality and could be a cheap alternative light source for the sensitive detection of opticall active substances. Besides, our polarization set up can be used to measure optical activity from any optically active substances.