The Pockels Effect is a phenomenon in which the refractive index of certain materials changes in response to an applied electric field. This effect is observed in non-centrosymmetric crystals, such as potassium niobate and lithium niobate. When an electric field is applied, the crystal's optical properties are altered, allowing for the modulation of light passing through it. This effect is widely used in various optical devices, including electro-optic modulators and switches. By controlling the electric field, these devices can manipulate light signals, making the Pockels Effect essential in telecommunications and laser technology.