Page 20 - Optical Switching And Networking Handbook

Introduction to Optical Communications 5

strength. However, if they all get together and lift at the same time,
their concentrated strength creates the result. Violà! They lift the
heavy object. Doing the same thing with light, by exciting a single
light particle individually, the beam is barely visible. However, if you
concentrate and excite all the light particles at the same time, you
create a very intense light beam.

Multimode fiber This type of fiber is used for hauling traffic over
short distances, such as within a building. In optical fiber technol-
ogy, multimode fiber is optical fiber that is designed to carry light
rays on different paths or modes concurrently, each at a slightly dif-
ferent reflection angle within the optical fiber core. Multimode fiber
transmission is used for relatively short distances because the
modes tend to disperse over longer lengths (this is called modal dis-
persion). Multimode fiber has a larger center core than single-mode
fiber. Figure 1-4 offers a comparison between multimode (thick) and
single-mode fiber.

62.5 micron 8.3 micron
Figure 1-4 center core center core
Comparison of
the fiber types

multimode fiber single-mode fiber