Observation of photon movement near Young’s double-slit

Abstract

The quantum interference phenomenon was observed in Young’s double-slit experiment using a single photon, and then, the validity of quantum mechanics was demonstrated. However, the reason these fringes appear has not been completely explained yet because photon motion has not been investigated in detail. We found a method to observe the motion of photons using the properties of optical fibers and showed vector diagrams of the photon motion near the double-slit. The photons gradually changed their direction while intersecting and formed interference fringes. In addition, utilizing the mode property of the fiber, we observed fringes at its output end, even when one of the two interfering waves could not transmit through the fiber.