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Polarized light from any suface?

  1. Aug 5, 2015 #1

    kelvin490

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    From a textbook I read something like this: "When sunlight is reflected from a horizontal surface, the
    plane of incidence is vertical, and the reflected light contains a preponderance of light that is polarized in the horizontal direction.... The manufacturer makes the polarizing axis of the lens material vertical, so very little of the horizontally polarized light reflected from the road is transmitted to the eyes."

    I just wonder whether all types of surfaces, even it is opaque, can reflect light with partially or completely polarized light which the perpendicular component of E field is dominant?

    For opaque surface like asphalt road, are there any critical angle so that all the reflected light are completely polarized (like the Brewster's angle in water, glass etc)?
     
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  3. Aug 5, 2015 #2

    DEvens

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    The key thing is that the surface have facets. That is, it has to have smooth flat parts that can reflect light like a mirror. If the surface is just amorphous then the scattering will tend to be too disorganized to see the polarization.

    I have seen polarized light coming off quite surprising surfaces. A manhole cover for example. It had been polished fairly smooth by traffic. The surface of a really smooth pond can show this. Sometimes really smooth snow can do it.

    Asphalt often has many small flat shiny facets. These can produce polarized light in the direction that is just right for the selection of facets turned the correct direction for you to see. It may be hard to detect this because if you turn the polarized lens of your sunglasses, then other facets can come into and go out of alignment.
     
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