8. Photon Polarization

This chapter delves into the intriguing behavior of photons as they interact with polarizing filters, using a quantum mechanical framework to explain the observations. Through four key experiments, the text illustrates how unpolarized light becomes polarized and how different alignments of polarizing filters affect light transmission. The first experiment demonstrates how a horizontally aligned filter halves the intensity of unpolarized light. The second experiment shows that a vertically aligned filter blocks all light that has passed through a horizontal filter. The third experiment reveals that adding a diagonally aligned filter after orthogonal filters does not change the outcome. However, the fourth experiment defies classical intuition, showing that inserting a diagonally aligned filter between horizontal and vertical filters allows some light to pass through. The chapter then applies the quantum mechanical framework to these experiments, modeling photons and polarizing filters as projection matrices and using rotation matrices to represent diagonally aligned filters. The text concludes by matching the experimental observations with the quantum mechanical calculations, providing a comprehensive understanding of photon polarization.