Kerr effect

The Kerr effect is a phenomenon where a material's optical properties change in response to an applied electric field, causing the material to become temporarily birefringent—meaning it splits light into two different polarizations. When an electric field is applied, the refractive index (how much the material bends light) varies depending on the light's polarization. This effect allows precise control of light in optical devices, such as modulators and switches, by electrically tuning the material's transparency or polarization without physically altering the material itself.