Which set correctly lists the three primary wavelength windows in a fiber optic system?

Which set correctly lists the three primary wavelength windows in a fiber optic system?

• A. 850, 1300, 1550
• B. 850, 1310, 1550
• C. 780, 1300, 1450
• D. 900, 1300, 1600

Answer: (A)

Wavelengths in fiber optics are chosen where silica fiber has the lowest loss and favorable dispersion, so signals travel farther with less distortion. The three main windows used for standard communications are around 850 nm, around 1310 nm (often listed as 1300 nm in some contexts), and around 1550 nm. The 850 nm region is popular for short-range, multimode links because LEDs/VCSELs work well there, even though the fiber attenuation is higher than in the infrared windows. The 1310 nm window offers near-zero dispersion, so pulses spread very little over distance, making it ideal for moderate lengths. The 1550 nm window has the lowest attenuation in silica and supports long-haul transmission with optical amplifiers, which is why it’s central to long-distance networks. Since the set includes these three well-known windows, it’s the best choice. Other options mix wavelengths outside these principal windows and don’t match the standard low-loss, low-dispersion regions.

Wavelengths in fiber optics are chosen where silica fiber has the lowest loss and favorable dispersion, so signals travel farther with less distortion. The three main windows used for standard communications are around 850 nm, around 1310 nm (often listed as 1300 nm in some contexts), and around 1550 nm. The 850 nm region is popular for short-range, multimode links because LEDs/VCSELs work well there, even though the fiber attenuation is higher than in the infrared windows. The 1310 nm window offers near-zero dispersion, so pulses spread very little over distance, making it ideal for moderate lengths. The 1550 nm window has the lowest attenuation in silica and supports long-haul transmission with optical amplifiers, which is why it’s central to long-distance networks. Since the set includes these three well-known windows, it’s the best choice. Other options mix wavelengths outside these principal windows and don’t match the standard low-loss, low-dispersion regions.