Theoretical approach on optical choppers for top-hat light beam distributions

This study achieves a rigorous mathematical analysis of optical choppers, considered in their general constructive solution, with n symmetrical wings. Their characteristic parameters and functions are ascertained: the profile of the transmitted flux, the transmission coefficient, and the significant energetic relationships that result. Both aspects that may be used in optical systems are approached: the simplified case, of a light fascicle of small diameter in the plane of the chopper, and the general case, of a fascicle of large diameter in the plane of the wheel. For both, a top-hat distribution of the light beam is presumed. Different cases are taken into account for the large diameter beam, with regard to the relationship between the angular dimensions of the chopper (angle of the wings and angle of the windows) and those of the light beam. A complete discussion regarding the different functions that may be obtained for the transmitted flux is obtained. From this mathematical analysis, the designing calculus of the device is developed, in its essential steps.