Faraday effect

Faraday effect states that magnetic field can affect the polarization of a linearly-polarized light.

Consider a linearly-polarized (LP) light passing through a pair of Helmholtz coils (along the direction of the magnetic field). Let’s decompose the LP light into its components: Left- and right-handed circular beams (LHC and RHC).

The electric field of each component exert a force on electrons which leads to their circular motion (how?). This motion creates a magnetic field in or against the direction of the applied magnetic field. This means different interaction of LHC and RHC beams with the applied magnetic field which results in a different refraction index and consequently a different propagation speed for LHC and RHC beams.

Combining back the two components (LHC and RHC) of the beam after the coils, produces a linearly-polarized light with a polarization angle different from the beam entered the magnetic field. This change in polarization angle is called “Faraday rotation”.




Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s