Introduction

Optical systems are frequently designed with no consideration given to light's polarization characteristics-and justly so. Many lens designers have successfully designed optics for their entire career without ever writing a Jones matrix. However, this is not true of all lens designers.

The use of polarization in optical systems has become more prevalent for two reasons: (1) Polarized sources are more available. Lasers have strongly influenced the optics industry since they first became commercially available in 1962. The fact that most are polarized means that optical systems utilizing lasers are also polarized. Additionally, sheet polarizers have enabled the easy, inexpensive generation of polarized polychromatic beams. (2) Electronically addressable polarization optics have greatly influenced the use of polarized light. Liquid crystal devices, magnetooptic media, and electrooptic modulators allow information to be electronically encoded into the polarization state of light. Liquid crystal devices have made the largest impact. Projection systems and head-mounted displays are new optical systems which are designed around liquid crystals.

This chapter introduces a variety of polarization topics:

1. It defines polarized light and polarization optics as well as the vocabulary surrounding these subjects.

2. It introduces the mathematics of polarized systems.

3. It discusses polarization aberrations and polarization ray tracing.

4. It discusses general approaches to solving common design challenges involving polarized light.

What Is Polarized Light?

Naturally occurring light, such as from the sun or candles, is often unpolarized-the electric field orientation (and the magnetic field orientation) varies unpredictably in the plane perpendicular to the direction of...