What are the two most common multimode wavelengths?

What are the two most common multimode wavelengths?

• A. 850, 1300
• B. 1310, 1550
• C. 780, 980
• D. 900, 1500

Answer: (A)

Multimode fiber systems rely on light sources that are inexpensive and easy to couple into the fiber, along with attenuation characteristics that keep the signal strong over short to moderate distances. The two most common wavelengths used are 850 nm and 1300 nm. The 850 nm region is ideal for multimode links because LEDs and VCSELs emit efficiently here, and multimode fibers have a high numerical aperture that makes coupling easy and robust. This makes 850 nm the go-to choice for short-reach links and fast, budget-friendly networks. The 1300 nm window, while famous for single-mode networks, is also practical for multimode systems because attenuation grows more slowly into the infrared and modern multimode components support this wavelength. It enables longer reach within a multimode setup than would be comfortable at 850 nm, while still staying within the multimode framework. Other options point toward contexts outside typical multimode data links: 1310/1550 are the standard corridors for single-mode fiber; 780/980 and 900/1500 aren’t the common pairing used for multimode data transmission.

Multimode fiber systems rely on light sources that are inexpensive and easy to couple into the fiber, along with attenuation characteristics that keep the signal strong over short to moderate distances. The two most common wavelengths used are 850 nm and 1300 nm.

The 850 nm region is ideal for multimode links because LEDs and VCSELs emit efficiently here, and multimode fibers have a high numerical aperture that makes coupling easy and robust. This makes 850 nm the go-to choice for short-reach links and fast, budget-friendly networks.

The 1300 nm window, while famous for single-mode networks, is also practical for multimode systems because attenuation grows more slowly into the infrared and modern multimode components support this wavelength. It enables longer reach within a multimode setup than would be comfortable at 850 nm, while still staying within the multimode framework.

Other options point toward contexts outside typical multimode data links: 1310/1550 are the standard corridors for single-mode fiber; 780/980 and 900/1500 aren’t the common pairing used for multimode data transmission.