Polarization

Polarization describes the orientation of the electric field vector of a light wave. While unpolarized light contains oscillations in many directions, polarized light is restricted to specific planes of oscillation.

Reflection on a Plane Surface

s-Polarization

p-Polarization

Superposition of s- and p-Polarized Light

Linearly Polarized Light

Circularly Polarized Light

Reflection on a Plane Surface

The plane of incidence (POI) is defined by the incident light beam and the surface normal.

Fig.1:Plane of incidence (POI) with light beam and surface normal

s-Polarization

In s-polarized light (also called σ-polarization or transverse-electric (TE)), the electric field is perpendicular to the plane of incidence.
Tip: “s” stands for “senkrecht” (German for perpendicular).

Fig.2:s-polarized light

p-Polarization

In p-polarized light (also called π-polarization or transverse-magnetic ™), the electric field oscillates within the plane of incidence, i.e., parallel to the POI.
Tip: “p” stands for “parallel”.

Fig.3:p-polarized light

Superposition of s- and p-Polarized Light

Any polarization state can be described as a superposition of s- (σ/TE) and p- (π/TM) polarized light.

Linearly Polarized Light

If s- and p-components are combined without a phase shift, the result is linearly polarized light.The electric field vector oscillates in a fixed direction.

Fig.4:Linearly polarized light

Circularly Polarized Light

If s- and p-components have a phase shift of 90° (π/2) and the same amplitude, the result is circularly polarized light.The electric field vector rotates at a constant rate – right- or left-handedly.

Fig.5:Circularly polarized light