The primary data encoding technology used in fiber-optic cables is non-return-to-zero (NRZ) encoding, and increasingly, more advanced forms of NRZ like NRZ-Inverted (NRZI) and modulation techniques like Pulse-Amplitude Modulation (PAM), particularly PAM4, are employed for higher. The primary data encoding technology used in fiber-optic cables is non-return-to-zero (NRZ) encoding, and increasingly, more advanced forms of NRZ like NRZ-Inverted (NRZI) and modulation techniques like Pulse-Amplitude Modulation (PAM), particularly PAM4, are employed for higher. Fiber-optic cables have revolutionized modern communication systems by enabling high-speed, long-distance data transmission through pulses of light. Unlike old-fashioned copper cables, fiber optics leverage sophisticated encoding methodologies to maximize bandwidth, reach, and reliability. This. The process of optical communication breaks down into a few simple steps: E/O converters use light-emitting elements such as semiconductor lasers, O/E converters use light-receiving elements such as photodiodes, and optical elements such as lenses are used at the input and output of optical fiber. They are arranged in bundles called optical cables and used to transmit signals over long distances.