Which data transmission method uses light signals to transfer data?

The transmission method that utilizes light signals to transfer data is fiber optic signals. This technology employs glass or plastic fibers to transmit information as pulses of light, which allows for very high-speed data transfer over long distances with minimal loss of signal quality.

Fiber optics are advantageous because they are less susceptible to electromagnetic interference, which can be a problem with other types of data transmission like copper wire. Additionally, due to the speed of light, fiber optic communication can achieve much greater bandwidth, making it ideal for applications requiring fast data transfer rates, such as internet and telecommunications.

In contrast, other transmission methods listed, such as radio signals, copper wire signals, and Bluetooth signals, rely on different mechanisms for data transfer, which do not involve light. For example, radio signals use electromagnetic waves, copper wires utilize electrical signals, and Bluetooth employs short-range radio frequency signals. These methods may be effective in their own right for various applications, but they do not offer the unique benefits associated with fiber optic technology.