Abstract:
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.