Final answer:
Brewster's angle is a principle in optics that explains the polarization of reflected light. An experiment can be done using a polarizing filter to determine the polarization of refracted light, which at Brewster's angle is slightly polarized vertically but not fully because significant horizontally polarized light is also refracted.
Step-by-step explanation:
The concept of Brewster's angle is fundamental in the study of light polarization. According to Brewster's law, when light is reflected at Brewster's angle from a smooth surface, the reflected light is 100% polarized parallel to that surface. To experimentally determine the polarization of the refracted light, one can use a polarizing filter, rotating it to find the angle at which the maximum amount of light is transmitted. This direction indicates the polarization of the refracted light. Although light reflected at Brewster's angle is fully polarized, the refracted light will only be slightly polarized vertically, not 100%. This is because only a fraction of the incident light is reflected, allowing significant horizontally polarized light to be refracted.
Brewster's angle has practical applications, notably in sunglasses, which can effectively block light reflected from surfaces like water or glass, provided the light is at Brewster's angle. This practical aspect of Brewster's angle emphasizes its significance in optics.