Polarized Film 1. What happens to white light as it passes through polarized fil
ID: 2031541 • Letter: P
Question
Polarized Film 1. What happens to white light as it passes through polarized film? Take two sheets of polarized film. Place them on a light-colored surface, with one on top of the other any orientation. Keeping the lower sheet in place, rotate the upper sheet. 2. a. How does the brightness of the paper vary with rotation of the upper sheet? b. How many times does the piece of paper go black (i.e, extinct) in 360° rotation of the upper sheet? Why is this happening? The paper goes black in cross-polarized light (xPL). The lower sheet represents the lower polarizer or the microscope, and the top sheet represents the upper polarizer on the microscope. So, with no mineral on the microscope stage (i.e., between the sheets of film), and with the polars crossed, wha image will you see? Why? 3.Explanation / Answer
Answer 1) White light is a superposition of many electromagnetic waves. In case of white light, the light waves consist of electric field vectors which vibrate in all planes that are perpendicular to the propagation direction of the waves.
A polarized film is a special material that can filter a white light beam and allow only the electric field vectors restricted to a single unique plane to pass. Hence, when white light passes through a polarized film, all the waves vibrate in a single plane and the waves become plane-polarized.