In 1848, Michael Faraday continued his magneto-optical investigations, demonstrating that applying strong magnetic fields to crystalline solids alters their principal optical axes and birefringence.

Electromagnetic Polarization Phase Shift¶

Faraday showed that the phase shift $\Delta \phi$ between orthogonal polarization states is modulated by magnetic field strength $B$:

$$\Delta \phi = \frac{2\pi d}{\lambda} (n_x - n_y) + V B d$$

Pathway to Maxwell’s Electromagnetic Theory of Light¶

Faraday’s experiments convinced James Clerk Maxwell that light waves are transverse electromagnetic oscillations propagating through electric and magnetic field space.