1.2 Optical Wavelength Bands
9
Fig. 1.4 Characteristics and operating ranges of the four key optical fiber link components
amplifiers that can operate in the 1310 and 1550 nm regions. In addition, doping
optical fibers with rare-earth elements such as Pr, Th, and Er creates optical fiber
amplifiers (called PDFA, TDFA, and EDFA devices, respectively). These devices
and the use of Raman amplification gave a further capacity boost to high-capacity
long-wavelength systems.
Special material-purification processes can eliminate almost all water molecules
from the glass fiber material, thereby dramatically reducing the water-attenuation
9
Fig. 1.4 Characteristics and operating ranges of the four key optical fiber link components
amplifiers that can operate in the 1310 and 1550 nm regions. In addition, doping
optical fibers with rare-earth elements such as Pr, Th, and Er creates optical fiber
amplifiers (called PDFA, TDFA, and EDFA devices, respectively). These devices
and the use of Raman amplification gave a further capacity boost to high-capacity
long-wavelength systems.
Special material-purification processes can eliminate almost all water molecules
from the glass fiber material, thereby dramatically reducing the water-attenuation