What type of light sources are used to test LANs for OM1 and OM2 fibers?

What type of light sources are used to test LANs for OM1 and OM2 fibers?

• A. LED
• B. VCSEL
• C. Laser diode
• D. Halogen lamp

Answer: (A)

For LAN testing on OM1 and OM2 multimode fibers, the light source should resemble what those networks historically used: LEDs. These fibers were designed around LED-based transmitters, which emit a broad, less coherent spectrum at around 850 nm. Using an LED as the test source provides testing conditions that match real‑world operation for OM1/OM2 networks, including how modal dispersion interacts with a broad spectral output. In contrast, laser diodes or VCSELs produce narrow, highly coherent light that suits laser-optimized fibers (like newer OM3/OM4) and high‑speed links, not the legacy multimode LAN setups. A halogen lamp is far too broad and unstable for meaningful fiber tests. So LED is the appropriate choice for testing LANs with OM1/OM2 fibers.

For LAN testing on OM1 and OM2 multimode fibers, the light source should resemble what those networks historically used: LEDs. These fibers were designed around LED-based transmitters, which emit a broad, less coherent spectrum at around 850 nm. Using an LED as the test source provides testing conditions that match real‑world operation for OM1/OM2 networks, including how modal dispersion interacts with a broad spectral output.

In contrast, laser diodes or VCSELs produce narrow, highly coherent light that suits laser-optimized fibers (like newer OM3/OM4) and high‑speed links, not the legacy multimode LAN setups. A halogen lamp is far too broad and unstable for meaningful fiber tests. So LED is the appropriate choice for testing LANs with OM1/OM2 fibers.