The Kerr Effect is a phenomenon in which the refractive index of a material changes in response to an applied electric field. This effect is named after the Scottish physicist John Kerr, who discovered it in 1875. When an electric field is applied, the material's optical properties can alter, allowing it to change how light passes through it. This effect is significant in various applications, including optical switches and modulators in telecommunications. By controlling the light's path, the Kerr Effect enables faster data transmission and improved performance in optical devices, making it a crucial concept in modern photonics.