The correct answer isOA (Optical Amplifier). Optical amplifiers are specifically designed to amplify optical signals without converting them into electrical signals, making them a critical component in long-distance optical networks.
Here's a breakdown of the options:
* MUX/DEMUX (Multiplexer/Demultiplexer):These devices combine or split multiple wavelengths in WDM (Wavelength Division Multiplexing) systems but do not amplify signals.
* OUT (Optical Transponder Unit):Converts optical signals from one wavelength to another but does not amplify them.
* FIU (Fiber Interface Unit):Provides physical connections for fiber cables but does not amplify signals.
* OSC (Optical Supervisory Channel):Used for transmitting management and monitoring information over the optical network but does not amplify signals.
* OA (Optical Amplifier):Amplifies optical signals directly, extending the reach of the network without the need for electrical regeneration. Common types include EDFA (Erbium-Doped Fiber Amplifier) and Raman amplifiers.
Optical amplifiers are essential for overcoming signal attenuation in long-haul and metro networks, ensuring that data can be transmitted over hundreds of kilometers without degradation.