New quantum optics laboratories to teach quantum physics

Table-top quantum optics experiments with correlated photon pairs have become a platform for advanced undergraduate laboratories that illustrate the fundamentals of quantum mechanics. Recent additions we developed are table-top versions of the Hong-Ou-Mandel experiment and Young’s double-slit experiment. We have introduced motorized components that reduce the data acquisition process, leaving time for students to engage in deciding on what measurements to make. For example, in an experiment to measure a violation of Bell’s inequality, students must find the projections that lead to the inequality instead of being given that information. More recently, we have developed a new type of polarization-based quantum eraser for single photons going through a Mach-Zehnder interferometer, where the distinguishing information is in the times of photon arrival. Quantum erasure after the interferometer then nulls the delays therefore, the distinguishability, resulting in the appearance of interference.