The transmission distance of a fiber-optic communication system has traditionally been limited by fiber attenuation and by fiber distortion. By using opto-electronic repeaters, these problems have been eliminated.
These repeaters convert the signal into an electrical signal, and then use a transmitter to send the signal again at a higher intensity than was received, thus counteracting the loss incurred in the previous segment. Because of the high complexity with modern wavelength-division multiplexed signals. including the fact that they had to be installed about once every 20 km (12 mi), the cost of these repeaters is very high.
fiber optic certifications
An alternative approach is to use optical amplifiers which amplify the optical signal directly without having to convert the signal to the electrical domain. One common type of optical amplifier is called an Erbium-doped fiber amplifier, or EDFA.
These are made by doping a length of fiber with the rare-earth mineral erbium and pumping it with light from a laser with a shorter wavelength than the communications signal (typically 980 nm). EDFAs provide gain in the ITU C band at 1550 nm, which is near the loss minimum for optical fiber.
These repeaters convert the signal into an electrical signal, and then use a transmitter to send the signal again at a higher intensity than was received, thus counteracting the loss incurred in the previous segment. Because of the high complexity with modern wavelength-division multiplexed signals. including the fact that they had to be installed about once every 20 km (12 mi), the cost of these repeaters is very high.
fiber optic certifications
An alternative approach is to use optical amplifiers which amplify the optical signal directly without having to convert the signal to the electrical domain. One common type of optical amplifier is called an Erbium-doped fiber amplifier, or EDFA.
These are made by doping a length of fiber with the rare-earth mineral erbium and pumping it with light from a laser with a shorter wavelength than the communications signal (typically 980 nm). EDFAs provide gain in the ITU C band at 1550 nm, which is near the loss minimum for optical fiber.
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