Sound and Oscillation

# polarized waves

Let’s look at the illustration above, in which we have a situation where a wave of velocity v is produced on a string. We see that this wave is intercepted by two slits, one vertical and one horizontal. The wave passes through the first slit, which is vertical, because it has the same direction as the plane of vibration of the string. In the second slit, we can verify that the wave does not pass through because it has a direction perpendicular to the direction of the slit.

If we make the same analysis with light, we will realize that this fact will also occur. We know that the light emitted is formed by electric and magnetic fields, in this way, a light source emits light in all directions. As a result, electric and magnetic fields are also produced in all directions, always being perpendicular to the direction of propagation.

When looking at the illustration above, we see that the light bulb is emitting light in various directions, so we can say that the light waves vibrate in various directions. In order for us to produce a polarized wave, we must place a polarizing crystal in the path of these waves. Only the waves that have the vibration plane coincident with the direction of the crystal slits were able to cross the polarizing crystal.

Therefore, we can say that light is polarized when it passes through the polarizer propagating in a single direction.

If we place another crystal, after the first polarizing crystal, whose polarizing slits are perpendicular to the direction of propagation of the previously polarized light, we will see that these waves will not cross the crystal. In this way we say that polarization is a property of transverse waves.

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