High Speed Light Choppers

Abstract

Mechanical light choppers are used in many optical systems with a great deal of success. At high PRF's, however, designers often tend to avoid their use because of stress and torque limitations. This article attempts to provide an optical engineer with sufficient information to compute the maximum stresses in a chopper wheel. It also provides curves for estimating the torque required to drive the wheel as well as general design guidelines. An example is shown of a 10-kHz chopper that was designed from the data presented and is now in use.