An interesting preface to the book,
"Introduction to DWDM Technology: Data in a Rainbow"
by Stamatios Kartalopoulos
Approx. 274 pages
spie.org
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Preface
Thousands of years ago someone tried to answer the question: Does light travel
always in a straight line, even if in a transparent medium, or can it follow its
curvature? Using a bucket of water with a hole at the bottom, he discovered the
latter how simple!
Sunlight rays crossing the morning dew droplets formed a rainbow of colors. Thus
the sun rays, composed of many colors, were demystified what a simple
observation! Sun rays, when reflected with shining bronze shields, were redirected
to selected points called estiai or foci. Furthermore, concentrated rays had so
much energy that they could warm up things or burn them. Soon thereafter, the
glassy optical lens was produced.
It was found that rays passing through a spherical lens did not create the best focal
point; today, this imperfection is known as lens sphericity. It was also discovered
that shapes based on hyperbolas or parabolas were better suited to optical
applications than those based on circles or spheres.
Simple experiments and observations of the past have helped our understanding
about the nature of things. Yesterday's science fiction is today's reality. The
electronic properties of conductors and semiconductors help to create or detect
light. Three crystals, each with different impurities and fused together, created a
transistor, which within a few years revolutionized the way we live. The wrist-size
communicator is no longer just fantasy in comic books. Pocket-size powerful
computers and credit-card-size communication devices are a reality. Low earth
orbit satellite (LEOS) communication networks are not "pic in the sky," but they
are roaming the silent skies. At the click of a button, one can access virtually any
part of the globe and hear and see events as they happen. Optical fiber has
wrapped around the globe like a ball of yarn connecting all continents and
transporting data at the speed of light. Direct-to-satellite communication enables
anytime-wireless connectivity between any two places in the world, as well as
providing global positioning services with accuracy of a few feet or inches! A
single optical fiber can transport the information of hundreds of thousands of
volumes within a second.
ABOUT THE BOOK
My interest in this field began early in my life when I pursued an undergraduate
degree in physics. My interest in optics continued during my graduate work when
I combined electronics, materials, and interferometric techniques. During the last
few years, I have been working on the subject of optical communications, both
SONET/SDH and ATM over SONET/SDH. My work on this subject culminated
into a book titled Understanding SONET/SDH and ATM (IEEE Press,
1999). Subsequently, I had the opportunity to expand my understanding of
multiwavelength transmission in optical media, now known as wavelength
division multiplexing (WDM), mainly through my active interest in this subject
during my undergraduate and graduate studies. Recently, I discovered that the
notes I had been compiling over the years had current educational
value, particularly in the area of DWDM.
The intention of this book is to explain in simple language the properties of light,
its interaction with matter, and how it is used to develop optical components such
as filters, multiplexers, and others that are used in optical communications. In
addition, the book provides an introduction to DWDM technology and to DWDM
communications systems. This book is not meant to replace related standards or to
provide a complete mathematical analysis of each optical device, although
mathematical relationships support some device functionality. DWDM is still
evolving, and it is strongly recommended that the reader interested in the details
of DWDM consult the most current updated standards. I wish you happy and easy
reading.
Stamatios V. Kartalopoulos
Lucent Technologies, Inc. |
