A method is described for modulating light according to any function describable by Fourier series. Any such wave shape can be synthesized although the mean light level cannot in general be controlled. Polar equations are developed for apertures that can be used in conjunction with rotating shutters having radial edged sectors left open, the combination generating sinnθ. Of particular interest are cases in which the aperture is restricted to any desired zone of the aperture disk. Synthesis is then accomplished by constructing a disk of several zones, each being used for a particular harmonic.