VCSELs and LEDs are used in _____ optical fiber systems.

VCSELs (Vertical-Cavity Surface-Emitting Lasers) and LEDs (Light Emitting Diodes) are primarily utilized in multimode optical fiber systems. This is because multimode fibers support multiple light modes or paths that travel down the fiber, which aligns well with the emission characteristics of LEDs and VCSELs.

LEDs provide a broad spectral output that can excite various modes within the multimode fiber, making them suitable for short-distance applications where bandwidth requirements are not as stringent. VCSELs, on the other hand, offer higher efficiency and performance advantages at specific wavelengths, which complement multimode fiber capabilities. They can also support higher data rates over moderate distances, making them ideal for local area networks (LANs) and data centers where multimode fiber is commonly used.

Singlemode fibers, in contrast, are designed to carry light directly down a single path and are typically utilized with laser sources that provide coherent light, such as distributed feedback lasers. Hybrid and coaxial systems also serve different applications and are not specifically designed around the use of LEDs and VCSELs like multimode systems are. Therefore, the choice of multimode optical fiber systems for VCSELs and LEDs is directly related to their ability to efficiently propagate multiple light modes,