Malus’s Law and a Dynamic Three-Polarizer System Available to Purchase

It is well known that Malus’s law can be used to quantitatively examine the polarization nature of light through various polarizing systems.¹ In particular, the three-polarizer system attracts considerable interest because it not only helps students deepen their understanding of Malus’s law (e.g., the three-polarizer paradox for the principle of quantum superposition²) but also offers opportunities to measure and control optical polarization in practice. In this work, we carry out a hands-on experiment involving a dynamic three-polarizer system with one continuously rotating polarizer in the middle position. With repeated (twice) applications of Malus’s law, we investigate the temporal waveforms of the transmitted light to show the validity of Malus’s law by dynamic means. More interestingly, our experiment indicates that multiple optical functions can be integrated into the dynamic three-polarizer setup for practical applications, including polarimetry analysis, rotation detection, and polarized pulse generation, which could provide a useful...