Electro-optical effect

The electro-optical effect describes the dependence of the refractive index of a medium on an external electric field .

The dependence of the refractive index on the electric field strength can be represented by a Taylor series : ${\displaystyle E}$

${\displaystyle n(E)\;=\;n_{0}+S_{1}\cdot E+S_{2}\cdot E^{2}+\dots }$

Here, the refractive index of a field in the absence of: ${\displaystyle n_{0}}$

${\displaystyle n_{0}=n(E=0)}$

• If it is , one speaks of the linear electro-optical effect or Pockels effect . is then relatively too negligibly small, except for extremely high electric fields. ${\displaystyle S_{1}\neq 0}$ ${\displaystyle S_{2}\,E^{2}}$ ${\displaystyle S_{1}\,E}$
• If and , one speaks of the quadratic electro-optical effect or Kerr effect . ${\displaystyle S_{1}=0}$ ${\displaystyle S_{2}\neq 0}$