Multi-mode fiber is designed to operate at which of the following wavelengths?

Multi-mode fiber is specifically designed for operating at shorter wavelengths, typically in the range of 850 nm and 1300 nm. These wavelengths are optimal for multi-mode applications because they allow for the highest light coupling and transmission efficiency over shorter distances compared to single-mode fibers, which primarily operate at longer wavelengths like 1300 nm and 1550 nm.

At 850 nm, multi-mode fibers utilize LEDs or VCSELs (Vertical Cavity Surface Emitting Lasers) as light sources, which are effective for data transmission in local area networks (LANs), data centers, and other applications requiring short to medium distances. The 1300 nm wavelength is also utilized in multi-mode installations to extend the range a bit while still supporting high-bandwidth applications.

The other choices include wavelengths that are either primarily associated with single-mode fiber (like 1550 nm) or not typically used for multi-mode applications, making them less suitable for this type of fiber. Multi-mode fiber's design and characteristics make it ideal for the wavelengths of 850 nm and 1300 nm, providing good performance in environments designed for moderate data rates over relatively short distances.