What is the Difference Between Linear Circular and Elliptical Polarization?

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The difference between linear, circular, and elliptical polarization lies in the orientation and amplitude of the electric field vectors of the light waves. Here's a summary of the differences:

  1. Linear Polarization: In linear polarization, the electric field of the light is confined to a single plane, and the electric field vectors are oriented in a single direction.
  2. Circular Polarization: Circular polarization is more complex than linear polarization. In circular polarization, the electric field consists of two linear components that are perpendicular to each other, equal in amplitude, and have a phase difference of 90°. If the electric field vector appears to rotate in a clockwise direction, the wave is referred to as right-circularly polarized; if it rotates counter-clockwise, it is called left-circularly polarized.
  3. Elliptical Polarization: Elliptical polarization is the most general description of polarized light and can include both linear and circular polarized light as special cases. In ellipsoidal polarization, the electric field of the light has two perpendicular linear components, but they have unequal amplitudes and a phase difference of 90°. The electric field vectors both rotate and change their magnitude, tracing out an elliptical shape.

In summary, linear polarization has a single plane of electric field vectors, circular polarization has two perpendicular electric field vectors with equal amplitudes and a 90° phase difference, and elliptical polarization has two perpendicular electric field vectors with unequal amplitudes and a 90° phase difference.

Comparative Table: Linear Circular vs Elliptical Polarization

The main differences between linear, circular, and elliptical polarization are related to the orientation and properties of the electric field in an electromagnetic wave. Here is a summary of their characteristics:

Polarization Type Description Electric Field Orientation Phase Difference
Linear The electric field of the light is restricted to a single plane where the propagation happens. Two perpendicular planes. 0°.
Circular Two linear planes in the light's electric field are strictly perpendicular to each other. Circularly polarized light is a special case of elliptical polarization. Two perpendicular planes. 90° (±[pi/2]).
Elliptical The light's electric field is at an elliptical propagation. Two perpendicular planes with different amplitudes and/or phase. Varies by 90°.

In summary, linear polarization has a single plane for its electric field, circular polarization has two perpendicular planes with a 90° phase difference, and elliptical polarization has two perpendicular planes with different amplitudes and varying phase differences.