  Unlike one-photon (first order) intensity correlation, two-photon (second
order) intensity correlation is known to be impossible to achieve by any
classical means. Over the last several decades, such quantum features have been
intensively demonstrated for anti-correlation in the Hong-Ou-Mandel effects and
nonlocal correlation in Bell inequality violation. Here, we present coherence
manipulations of attenuated laser light to achieve such a quantum feature using
pure coherence optics. Unlike the common understanding of the two-photon
intensity correlations, the present coherence approach gives an equivalent
classical version to the known quantum approach. To excite the coherence
quantum features between paired coherent photons, a selective measurement
process plays an essential role in creating the inseparable joint phase
relation between independent local parameters. The local randomness is also
satisfied in both parties using orthonormal polarization bases of a single
photon.
