文档介绍：How Fiber Optics Works
FEATURE by Greg Sanger
echnologists and investors know about the rapid rise the receiving individual puter.
TTand subsequent slump in the fiber-optics industry In the information channel, the signal generated by the
during the past several years. Some have likened these transmitter travels from transmitter to receiver (Figure 1).
changes to the swings in the semiconductor Such channels can be either unguided or guided. Radio,
industry during the 1960s. Although sales television, and microwaves are examples munica-
Light answers remain slow, it is clear that the industry will tion by an unguided channel. Guided channels include
come back bigger than ever. The industry is twisted-pair copper wire, coaxial cable, and optical fiber.
the bandwidth expected to recover for the same reason that Examples of other munications systems
fiber optics became of interest initially—use of include hand signals, ship-to-ship and ship-to-shore
challenge the and the pressure for faster down- blinker lights, traffic signals, and automobile turn signals.
loads and transfers continue to increase rapid- Normally, optical fibers are bundled into cables that
ly. Indeed, the demand for increased band- contain more than 100 fibers. Hence, a transceiving sta-
width in the next few years is expected to grow at an tion will contain hundreds of these channels