Quantum interference of multimode two-photon pairs with a Michelson interferometer

We perform the second-order quantum interference experiment with the multimode photon pairs produced via an optical parametric oscillator far below threshold in a Michelson interferometer, measure the second-order correlation function in different cases. We find when the interferometer is highly unbalanced, the shape of the second-order correlation function is clearly dependent on the path length difference between two interfering beams. On the contrary, when the interferometer is nearly balanced, beside its height, the shape of the second-order correlation function is independent on the small path length difference. The second-order correlation function shows a multipeaked structure in both cases. All experimental results agree very well with the theoretical predictions.