Page 19 - Optical Switching And Networking Handbook

4 Chapter 1

Figure 1-1
Amplifiers boost Amplifier Amplifier
weak signals.

Signal weakening

Figure 1-2
Coaxial cables
handle high-
frequency
transmissions
especially for TV.

Modulator
Figure 1-3
A modulator
converts the
electrical pulses
into light pulses.

Input of electrical pulses Output of light pulses

converts information from one form and back again, depending on
the direction.

Laser (light amplification by simulated emission of radiation) A
light source created by exciting atoms, causing them to emit light of
a specific wavelength (frequency) in a focused beam. Think of a
group of people who are all trying to lift a very heavy object, one at
a time. Nothing happens because they individually have little