Two photons arrive at a hypothetical 50:50 Beam-Splitter with no phase shift between reflected and transmitted modes. One enters the Left side and the other the Bottom side of the BS as shown in Fig.1 of the link below: https://drive.google.com/open?id=0B5JsDLKoUSA5emk5Qk9nUHVIelE Each photon is in one of two possible quantum states, |0> and |1>, characterized by a phase of 0 or 180 degrees, respectively. The two photons leave the BS, emerging from the Top or Right sides, being detected by Photo-Detectors, and having their phases measured by PDTop and PDRight. Assuming that the BS is lossless, the two photons are detected simultaneously by PDTop, PDRight, or each one is detected by a different Photo-Detector at simultaneous time-stamps. With regard to this third scenario, if the two photons are allowed to interfere at the BS, it would seem the quantum state of the photon pair would be a Bell State of form C(|00> + |11>) (Fig.2), or, in other words, due to destructive interference, measuring the phase at the photon arriving at PDTop would tell us what is the measured phase of the photon at PDRight, at any time, no matter the distance between the Photo-Detectors. In this case, the two photons would appear to be entangled. Is it possible to create entangled photon pairs in this way, only by allowing them to interfere? I would very much appreciate your opinions. Thank you very much!