light intensity equation light intensity equation unpolarized

Such light is said to be unpolarized because it is composed of many waves with all possible directions of polarization. The Sun and many other light sources produce waves that are randomly polarized (see Figure 27.39).

Vertical slits pass vertically polarized waves and block horizontally polarized waves. The first is said to be vertically polarized, and the other is said to be horizontally polarized. Thus we can think of the electric field arrows as showing the direction of polarization, as in Figure 27.37.įigure 27.38 The transverse oscillations in one rope are in a vertical plane, and those in the other rope are in a horizontal plane. For an EM wave, we define the direction of polarization to be the direction parallel to the electric field.

(This is not the same type of polarization as that discussed for the separation of charges.) Waves having such a direction are said to be polarized. Polarization is the attribute that a wave’s oscillations have a definite direction relative to the direction of propagation of the wave. There are specific directions for the oscillations of the electric and magnetic fields. As noted earlier, EM waves are transverse waves consisting of varying electric and magnetic fields that oscillate perpendicular to the direction of propagation (see Figure 27.37). Light is one type of electromagnetic (EM) wave. Polarizing sunglasses are particularly useful on snow and water.

As a result, the reflection of clouds and sky observed in part (a) is not observed in part (b). Part (b) of this figure was taken with a polarizing filter and part (a) was not. Figure 27.36 These two photographs of a river show the effect of a polarizing filter in reducing glare in light reflected from the surface of water.

Light intensity equation light intensity equation unpolarized