TABLE OF CONTENTS A wave is a traveling disturbance. Waves are important because all information that we receive via hearing and seeing is transmitted via waves. While light has both particle-like and wave-like properties, the present discussion will focus on the wave-like character of light. The focus in this chapter is on the interaction of these light waves with polarizers, such as are found in some sunglasses, and material media. Some related topics will be addressed in later chapters, those needed to understand displays will be discussed in this chapter.
We will address the following questions.
What is a wave? How is a wave represented?
What is light? What makes light waves different than waves on water or sound waves in air?
What is a polarizer, and how does it work?
How is the interaction of light with essentially transparent materials explained?
Almost all of the applications of liquid crystals that we shall discuss concern how light and liquid crystals interact. To understand this phenomenon, one must understand some of the basic properties of light.
We begin by noting that light has wave-like properties, and in elementary discussions may be treated as a wave. A wave is characterized by a traveling disturbance in which the disturbance propagates but the media, as a whole, does not move. Broadly, there are two different types of waves: transverse waves in which the displacement, the movement caused by the disturbance, is perpendicular to the direction the wave propagates, and longitudinal waves where the...
