Warm-Up Exercise 27

Due 12:15 pm, Mon 29 Oct 2012

Physics 123, Fall 2012

Reading assignment: 38.6

What does it mean to say that a given light beam is polarized? Or unpolarized?

Polarized--all of the electric field vectors of a light ray bear a particular relationship to each other as the ray travels. Ex: electric field oscillates up and down = "vertically polarized". Unpolarized--there is no relationship between the electric field vectors as the ray travels. The electric field oscillates in random directions.

In the discussion accompanying the figure shown above, the text explains how a certain reflection angle can lead to polarization. In your own words, explain how this works.

At a certain angle one of the polarizations cannot reflect. That's called Brewster's angle. If you shine an unpolarized light beam at the surface, the reflected beam will therefore be entirely the OTHER polarization.

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