Light sources used to test multimode Local Area Networks (LANs) normally use what type of electro-optical component?

The use of Light Emitting Diodes (LEDs) or Vertical-Cavity Surface-Emitting Lasers (VCSELs) as the electro-optical components for testing multimode Local Area Networks (LANs) stems from their suitability for the specific requirements of multimode fiber.

Multimode fibers have a core large enough to allow multiple light modes to propagate simultaneously, which means they can effectively utilize the broader spectral output of LEDs and the more coherent light from VCSELs. LEDs provide a wide spectral output, which is beneficial for transmitting over the multimode fiber since the multimode can support different light wavelengths, allowing for more efficient signal transmission over shorter distances typically found in LAN setups.

VCSELs, on the other hand, offer a more efficient and compact option with higher power and quality than generic LEDs. They are also designed to emit light in a narrow beam, reducing modal dispersion and increasing the overall performance for data communication over multimode fibers.

Together, these components align perfectly with the needs for testing and certifying multimode LANs, making this choice ideal for ensuring performance parameters meet network specifications.