What is linear Polarizaion?

# What is linear Polarizaion?

The study of EM waves is done for various properties like speed, intrinsic impedance, power etc. But, when we study EM waves, polarization is one of the important properties that needs special attension. Let’s see graphically the linear polarization of EM wave.

## What is Electromagnetic Wave?

Electromagnetic wave is a systematic movement of varying E and varying H, which transports energy from one location to the other.The existanance of an EM wave is evident by the Maxwell’s equations.

Using Maxwell’s equations we can prove that electromagnetic energy can be transported from one point in the space to other.

You can watch the quick video below or read along.

## What is Polarization of Wave?

Polarization of wave denotes the orientation of E field as a function of time at any fixed position.

We know that EM wave carries elctromagnetic energy where E and H fields are present. The magnitude and direction of fields are continuously varying as wave propagates. So how the E field is vaying at certain fixed point is known as the polarization.

If the E field orientation is lying along line then it would be called as linear polarization. If it takes the form of circle then it would be called as circular polarization. ANd if takes the form of ellipse then it will be elliptical polarization.

Remember while defining polarization, concentrate only on the E field variations not on H field. It is quite obvious that once you get the orientation of E field, you can find orientation of H anytime from the E, H and direction of propagation relation.

## Linear Polarization

Consider our wave is trvelling along +Z direcion and E field is along X and H is along Y. H is not shown in the diagram. Let us take z = constan plane as seen from the figure below.

Now as EM wave oropagates along +Z direction, you can clearly observe that the orientation of E field is lying along the line.

So, the E field orientation or variations in the E field with respect to time is lying along the line. Hence it is linear polarization. Simple!

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