1 Laboratory 2 : Single Photon Interference

The purpose of this experiment was to observe the wave-particle duality of photons by demonstrating that single photons can and do interfere with themselves. This was accomplished through the use of a Mach-Zehnder interferometer and a Young double slit apparatus. The EMCCD camera used for both experiments can detect single photons to some degree, thus demonstrating the particle nature of photons. The camera showed that when the Mach-Zehnder polarizers make “which-path” completely ambiguous, single photons would accumulate in an interference pattern. Conversely, the Mach-Zehnder interferometer confirmed that when “whichpath” information is known via crossed polarizations, the wave phenomenon of interference is destroyed. The double slit further confirmed interference phenomena on a single photon level.