Page 202 - Photonics Essentials an introduction with experiments

Optical Fibers and Optical Fiber Amplifiers

196 Advanced Topics

Figure 9.3. Attenuation of optical fiber as a function of wavelength. Absorption peaks
from residual O–H groups can be seen at 1230 nm and 1370 nm. The letters OVD, IVD,
and VAD refer to different styles of vapor deposition used to make the glass preform
from which the fiber is drawn. (Adapted from Wilson and Hawkes, Optoelectronics,
Prentice-Hall, 1998, reproduced with permission.)

Figure 9.4. A schematic diagram of the SiO 2 network. The silicon atoms (dark circles)
are not located in a regular pattern. The atomic potential associated with the silicon
atoms is also irregular. The fluctuations from regularity act to scatter light, causing at-
tenuation in optical fibers.

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