Electro-optic devices are instruments that utilize the interaction between electric fields and light to control optical properties. These devices can modulate, switch, or manipulate light signals, making them essential in telecommunications, imaging systems, and laser technology. Common examples include electro-optic modulators and liquid crystal displays (LCDs). The principle behind electro-optic devices is the Pockels effect or Kerr effect, which describes how the refractive index of certain materials changes in response to an electric field. This property allows for precise control of light, enabling advancements in various fields such as fiber optics and optical computing.