
terahertz frequencies and higher, whereas electronics are usually considered as
electromagnetic waves oscillating at gigahertz frequencies and lower. Using optics
as a carrier, extremely high signal bandwidths can be transported. The optical fiber
provides a low-loss medium to do this, and optical amplifiers can re-amplify the
signal with nearly ideal noise levels.
This chapter focuses on PLCs used with signal-transporting optical fibers. There
are two main ways to achieve high bandwidth on an optical fiber, and PLCs are
instrumental in both. One is to increase the number of “channels” on a fiber, each
channel being at a different carrier frequency ...