October 2013
Intermediate to advanced
400 pages
10h 16m
English
Fiber optics distribute CATV signals over large geographic areas with higher quality video and lightning immunity. However, CATV systems carrying 100 or more predominantly analog channels demand a linear system. In a truly linear system, the system's output is directly proportional to the system's input. However, in reality, most systems exhibit some degree of nonlinearity. The biggest challenge usually lies with the laser diode. Its light-to-current (LI) curve is usually close to a straight line above the threshold current but is never perfectly straight. These deviations from linear operation creates problems in systems that demand high linearity. Figure 15.1 illustrates a typical light-to-current ...