Devices based on liquid crystals have become the mainstay of display
technology used in mobile devices, vehicles, computer systems, and almost
any other opportunity for information display imaginable. Not quite as well
appreciated, even in the engineering world, is the influence of liquid crystals
on optical systems ranging from adjustable lenses and filters to adaptive optics
systems. Many excellent books have been written on the chemistry and
physics of liquid crystals as well as on the technical devices that make use of
liquid crystals. The aim of this book is to provide the optics community with a
primer on liquid crystals that focuses on the optical components made from
these fascinating materials.
While the use of liquid crystals as components of displays is recognized by
most engineers and scientists, when it comes to liquid crystal devices used as
optical component emulators or spatial light modulators, many people have
little exposure to the technology or the basic principles involved. In this text
we try to strike a balance between providing sufficient background material to
support easy understanding of the topic while pressing forward into the
fascinating technology of liquid crystals.
We hope that Introduction to Liquid Crystals for Optical Design and Engineering
provides interested readers with a functional overview of the topic, its history, and its
applications so that they can move on to more advanced texts and continue to
grow their abilities in this field. While this book is not meant to be a complete
mathematical treatise on the basics and applications of liquid crystals, we do
try to fill in some of the gaps, in particular, in the area of adaptive optics
applications. Indeed, adaptive optics applications were the motivation for our
initial involvement in liquid crystal devices.
Chapter 1 provides a general introduction to liquid crystals, a history, and
some of the nomenclature to move farther into the topic. Chapter 2 is an
overview of the properties of liquid crystals and introduces the idea of the
alignment of their molecules. Chapter 3 covers the optical properties of
polarization and birefringence as they apply to liquid crystals—properties that
make them interesting for engineers and scientists. Chapter 4 presents liquid
crystal displays and discusses why they are so useful in today’s technology.
Chapter 5 provides an introduction to spatial light modulators and their importance in manipulating the phase and intensity of light. Chapter 6 increases our appreciation of spatial light modulators as optical element
emulators. Chapter 7 provides details of the use of liquid crystals as
components in adaptive optics systems. Chapter 8 rounds out the topics of the
book by pointing toward future uses of liquid crystals. A historical overview
of the literature on liquid crystals is provided in Chapter 9, which includes a
chronological list of relevant publications, starting from 1888.
We greatly appreciate all of the colleagues and friends who have both
directly and indirectly helped us in preparing and writing this book, and we
are grateful for their unswerving and unselfish support. We would particularly
like to thank Jonathan Andrews, Chris Wilcox, and Ty Martinez of the Naval
Research Laboratory; David Wick of Sandia National Laboratories; Don
Payne of Honeywell; and Jeffery Baker of Baker Adaptive Optics and Laird
Thompson of the University of Illinois at Urbana-Champaign for their efforts
with us in the laboratory exploring many of the more interesting facets of
electro-optics. We apologize if we have inadvertently left anyone off this list
but sincerely appreciate all of the help and support of our colleagues at both
the Naval Research Laboratory in Albuquerque, New Mexico and New
Mexico Institute of Mining and Technology in Socorro, New Mexico.
While we have benefited from the assistance of many individuals in
preparing this work, any errors that remain in the text are ours to fix. We
would appreciate receiving any assistance in this in the form of comments and
corrections. Please direct any correspondence to the authors c/o New Mexico
Tech, Electrical Engineering Department, Socorro, NM 87801, USA.
We are most grateful for the support of SPIE for their interest in
publishing this work as part of the Tutorial Text Series and particularly Dara
Burrows, our editor, for putting this work into its final form.
Sergio R. Restaino
Naval Research Laboratory
Scott W. Teare
New Mexico Institute of Mining and Technology
July 2015
