2
1 Perspectives on Lightwave Communications
speculated that the high losses were a result of impurities in the fiber material, and
that the losses potentially could be reduced significantly in order to make optical
fibers a viable transmission medium. In 2009 Charles K. C. Kao was awarded the
Nobel Prize in Physics for his pioneering insight and his enthusiastic international
follow-ups in promoting the further development of low-loss optical fibers. These
efforts led to the first ultrapure fiber being fabricated in 1970, only four years after
Kao and Hockman’s prediction [5]. This breakthrough led to a series of technology
developments related to optical fibers. These events finally allowed practical optical
fiber based lightwave communication systems to start being fielded worldwide in
1978.
The goal of this book is to describe the various technologies, implementation
methodologies, and performance measurement techniques that make fiber optic
telecom systems possible. The reader can find additional information on the theory
of light propagation in fibers, the design of links and networks, and the evolution of
optical fibers, photonic devices, and optical fiber communication systems in a variety
of reference books [6], tutorial papers [7-12], textbooks [13-20], and conference
proceedings [21-23].
This chapter is organized as follows:
• Section 1.1 gives the motivations behind the development of optical fiber
transmission systems.
• Section 1.2 defines the different spectral bands that describe various operational
wavelength regions used in optical communications.
• Section 1.3 reviews decibel notation for expressing optical power levels.
• Section 1.4 illustrates the basic hierarchy for electrically multiplexing digitized
information streams used on optical links.
• Section 1.5 describes basic optical multiplexing methods for greatly increasing
the information-handling capacity of optical links.
• Section 1.6 introduces the functions and implementation considerations of the
key elements used in optical fiber links.
• Section 1.7 describes the evolution and advances in fiber optic telecom networks
that have resulted from the progressive introduction of emerging technologies.
• Section 1.8 lists the main classes of standards related to optical communication
components, system operations, and installation procedures.
Next, Chaps. 2–12 describe the purpose and performance characteristics of the
major elements in an optical link. These elements include optical fibers, light sources,
photodetectors, passive optical devices, optical amplifiers, and active optoelectronic
devices used in multiple-wavelength networks. Chapters 13 and 14 show how the
elements are put together to form links and networks and explain measurement
methodologies used to evaluate the performance of lightwave components and links.
1 Perspectives on Lightwave Communications
speculated that the high losses were a result of impurities in the fiber material, and
that the losses potentially could be reduced significantly in order to make optical
fibers a viable transmission medium. In 2009 Charles K. C. Kao was awarded the
Nobel Prize in Physics for his pioneering insight and his enthusiastic international
follow-ups in promoting the further development of low-loss optical fibers. These
efforts led to the first ultrapure fiber being fabricated in 1970, only four years after
Kao and Hockman’s prediction [5]. This breakthrough led to a series of technology
developments related to optical fibers. These events finally allowed practical optical
fiber based lightwave communication systems to start being fielded worldwide in
1978.
The goal of this book is to describe the various technologies, implementation
methodologies, and performance measurement techniques that make fiber optic
telecom systems possible. The reader can find additional information on the theory
of light propagation in fibers, the design of links and networks, and the evolution of
optical fibers, photonic devices, and optical fiber communication systems in a variety
of reference books [6], tutorial papers [7-12], textbooks [13-20], and conference
proceedings [21-23].
This chapter is organized as follows:
• Section 1.1 gives the motivations behind the development of optical fiber
transmission systems.
• Section 1.2 defines the different spectral bands that describe various operational
wavelength regions used in optical communications.
• Section 1.3 reviews decibel notation for expressing optical power levels.
• Section 1.4 illustrates the basic hierarchy for electrically multiplexing digitized
information streams used on optical links.
• Section 1.5 describes basic optical multiplexing methods for greatly increasing
the information-handling capacity of optical links.
• Section 1.6 introduces the functions and implementation considerations of the
key elements used in optical fiber links.
• Section 1.7 describes the evolution and advances in fiber optic telecom networks
that have resulted from the progressive introduction of emerging technologies.
• Section 1.8 lists the main classes of standards related to optical communication
components, system operations, and installation procedures.
Next, Chaps. 2–12 describe the purpose and performance characteristics of the
major elements in an optical link. These elements include optical fibers, light sources,
photodetectors, passive optical devices, optical amplifiers, and active optoelectronic
devices used in multiple-wavelength networks. Chapters 13 and 14 show how the
elements are put together to form links and networks and explain measurement
methodologies used to evaluate the performance of lightwave components and links.