Deciphering the diffraction pattern from a longitudinally separated slit

While the knife-edge and slit diffractions are well studied, the diffraction patterns from a longitudinally separated slit have not caught much attention. This study fills the research gap. It turns out that the asymmetric pattern of this type of diffraction can be explained neither by the wave theory nor by quantum electrodynamics. Using a geometrical diffraction model, the study can explain the asymmetric diffraction pattern both qualitatively and quantitatively. The experimental tests lend support to the geometrical diffraction model.