What is a short length of fiber that serves as an amplifier in fiber optic networks, allowing light signals to travel further while retaining signal strength?

What is a short length of fiber that serves as an amplifier in fiber optic networks, allowing light signals to travel further while retaining signal strength?

• A. An erbium-doped fiber amplifier
• B. A silicon photomultiplier
• C. A chromatic dispersion compensator
• D. A Gaussian filter

Answer: (A)

In-line optical amplification uses a short section of fiber doped with erbium to boost the signal directly in the fiber. When pumped with light at specific wavelengths, the erbium ions provide gain for signals around 1550 nm, compensating for loss so the light can travel farther without degrading. This keeps the signal in the optical form, which is essential for long-haul fiber networks. The others don’t perform this function: a silicon photomultiplier is a light detector, a chromatic dispersion compensator fixes travel-time differences between wavelengths, and a Gaussian filter shapes the spectrum. So the device that acts as an amplifier in this context is an erbium-doped fiber amplifier.

In-line optical amplification uses a short section of fiber doped with erbium to boost the signal directly in the fiber. When pumped with light at specific wavelengths, the erbium ions provide gain for signals around 1550 nm, compensating for loss so the light can travel farther without degrading. This keeps the signal in the optical form, which is essential for long-haul fiber networks. The others don’t perform this function: a silicon photomultiplier is a light detector, a chromatic dispersion compensator fixes travel-time differences between wavelengths, and a Gaussian filter shapes the spectrum. So the device that acts as an amplifier in this context is an erbium-doped fiber amplifier.