Optical choppers with circular-shaped windows: Modulation functions

In this paper the non-linear process of light modulation performed by optical choppers is studied. The real functions of the transmitted flux, with transition portions are derived, in contrast to approximate approaches, of flux functions considered as series of rectangular impulses. An exact mathematical model of the dynamic phenomenon is thus achieved. Top-hat light beam distributions are considered. We are developing in this paper a new type of rotating wheel with windows that have circular-shaped edges. This is the general case of the classical configuration, of choppers with wings (or, equivalent, with sector-shaped windows) that we have solved in a previous study for all its possible relationships between the geometry of the wheel and the diameter of the light beam in the plane of the chopper. This relationship is also considered in this study, while the configuration of the new device allows for more degrees of freedom in the designing process. From this discussion, the various possible geometries of choppers that may generate a required function of the transmitted flux are obtained.