Electro-optic modulators are devices that control the intensity, phase, or frequency of light using an electric field. They work by exploiting the electro-optic effect, where the refractive index of a material changes in response to an applied voltage. This allows for precise manipulation of light signals, making them essential in various applications like telecommunications and laser systems. These modulators are commonly used in fiber optic communication to encode information onto light waves, enabling high-speed data transmission over long distances. Their ability to rapidly switch light on and off makes them crucial for modern optical systems, enhancing performance and efficiency.