Nonimaging Optics

10 CONSEQUENCES OF SYMMETRY

Narkis Shatz, John C. Bortz

Science Applications International Corporation, San Diego, CA

10.1 INTRODUCTION

The flux-transfer efficiency of passive nonimaging optical systems—such as lenses, reflectors, and combinations thereof—is limited by the principle of étendue conservation. As a practical matter, many nonimaging optical systems possess a symmetric construction, translational and rotational symmetries being the most common. In this chapter, we find that for such symmetric optical systems a further, more stringent limitation on flux-transfer efficiency is imposed. This performance limitation, which may be severe, can only be overcome by breaking the symmetry of the optical system.

In the geometrical optics approximation, ...