We study a general theory on the interference of two-photon wavepacket in a beam splitter (BS). We find that the perfect coalescence interference requires a symmetric spectrum of two-photon wavepacket which can be entangled or un-entangled. Furthermore, we introduce a two-photon wavepacket with anti-symmetric spectrum, which is related with photon entanglement and shows a perfect anti-coalescence effect. The theory present uniform and complete explanation to two-photon interference.
@article{arxiv.quant-ph/0301060,
title = {Coalescence and Anti-Coalescence Interference of Two-Photon Wavepacket in a Beam Splitter},
author = {Kaige Wang},
journal= {arXiv preprint arXiv:quant-ph/0301060},
year = {2009}
}