What is the difference between single-mode and multi-mode fiber?

Single-mode fiber supports a single light path, allowing light to travel directly down the fiber without much reflection. This design results in less modal dispersion, making single-mode fiber ideal for long-distance communication, as it can transmit data over greater distances without losing signal quality. In contrast, multi-mode fiber supports multiple light paths or modes, as it has a larger core diameter that allows for multiple reflections within the fiber. This characteristic can lead to modal dispersion, which limits the distance over which the signals can travel effectively.

Understanding this distinction is crucial for determining the appropriate type of fiber for specific applications. Single-mode fiber is typically preferred for long-range telecommunications, while multi-mode fiber is often used in shorter distance applications, such as within buildings or campuses. Therefore, the key difference is in the number of light paths that each type of fiber supports.