Observation of nonclassical photon statistics due to quantum interference.

Phase-dependent photon statistics is observed in the mixed field of a narrow band two-photon source and a coherent field. At a certain phase, the nonclassical effect of photon antibunching occurs while at another the photon bunching effect appears. Furthermore, we observed a novel nonclassical phenomenon that exhibits more complex structure. The different features in photon statistics are attributed to a two-photon interference effect.