Research on the Hong-Ou-Mandel interference with two independent sources

In this paper, we carry out investigation on the HOM interference between two independent photons by using interference filters with different bandwidth both in theory and experiment. Our experimental results are consistent with the theoretical predictions. From the experimental and theoretical results, we find that interference filters with a narrower bandwidth can help to give a larger coherence length, due to the broadening of photon wave-packet in the spatial domain, resulting in an higher interference visibility. Furthermore, a combination of interference filters with different bandwidths may help to achieve a nice balance between coincidence counting rate and interference visibility. Our present work might provide valuable reference for further implementation of HOM interference in the field of quantum information.