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zonde
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I am considering http://en.wikipedia.org/wiki/Hong%E2%80%93Ou%E2%80%93Mandel_effect"
Wikipedia explanation says that "Therefore, when two identical photons enter a 50:50 beam splitter, they will always exit the beam splitter in the same (but random) output mode."
And yet before this it says: "The Hong–Ou–Mandel effect is indeed due to indistinguishability of two-photon amplitudes but not due to the photon bunching effect of individual photon wavepackets."
It seems a bit awkward i.e. two photons are always in the same output mode yet they are not bunching.
If we look at this experiment:
http://arxiv.org/abs/0809.3991"
it becomes a bit more clear. Paper says:
"A two-fold coincidence detection event between either [tex]D_{Q1H}[/tex] and [tex]D_{Q2V}[/tex] or [tex]D_{Q1V}[/tex] and [tex]D_{Q2H}[/tex] indicates a projection on [tex]\psi^-[/tex]. On the other hand, a coincidence detection event between either [tex]D_{Q1H}[/tex] and [tex]D_{Q1V}[/tex] or [tex]D_{Q2H}[/tex] and [tex]D_{Q2V}[/tex] indicates a projection on [tex]\psi^+[/tex]."
Here [tex]D_{Q1H}[/tex] and [tex]D_{Q1V}[/tex] are detectors after PBS that is behind one port of beam splitter but [tex]D_{Q2H}[/tex] and [tex]D_{Q2V}[/tex] are behind other port of beam splitter.
So we have coincidences equally behind the same port of beam splitter or behind different ports of beam splitter.
So we can say that photons really appear in different ports of beam splitter and yet if we make measurement by placing detectors directly after ouputs of beam splitter (without PBSes) we do not detect coincidences. As it is demonstrated in Fig.2 of the same paper.
Does it seems good so far?
And now there is the question about fair sampling assumption. It seems like such properties of HOM dip utterly contradict fair sampling assumption as applied to photon detection.
Or maybe there is alternative viewpoint that justifies fair sampling assumption?
Wikipedia explanation says that "Therefore, when two identical photons enter a 50:50 beam splitter, they will always exit the beam splitter in the same (but random) output mode."
And yet before this it says: "The Hong–Ou–Mandel effect is indeed due to indistinguishability of two-photon amplitudes but not due to the photon bunching effect of individual photon wavepackets."
It seems a bit awkward i.e. two photons are always in the same output mode yet they are not bunching.
If we look at this experiment:
http://arxiv.org/abs/0809.3991"
it becomes a bit more clear. Paper says:
"A two-fold coincidence detection event between either [tex]D_{Q1H}[/tex] and [tex]D_{Q2V}[/tex] or [tex]D_{Q1V}[/tex] and [tex]D_{Q2H}[/tex] indicates a projection on [tex]\psi^-[/tex]. On the other hand, a coincidence detection event between either [tex]D_{Q1H}[/tex] and [tex]D_{Q1V}[/tex] or [tex]D_{Q2H}[/tex] and [tex]D_{Q2V}[/tex] indicates a projection on [tex]\psi^+[/tex]."
Here [tex]D_{Q1H}[/tex] and [tex]D_{Q1V}[/tex] are detectors after PBS that is behind one port of beam splitter but [tex]D_{Q2H}[/tex] and [tex]D_{Q2V}[/tex] are behind other port of beam splitter.
So we have coincidences equally behind the same port of beam splitter or behind different ports of beam splitter.
So we can say that photons really appear in different ports of beam splitter and yet if we make measurement by placing detectors directly after ouputs of beam splitter (without PBSes) we do not detect coincidences. As it is demonstrated in Fig.2 of the same paper.
Does it seems good so far?
And now there is the question about fair sampling assumption. It seems like such properties of HOM dip utterly contradict fair sampling assumption as applied to photon detection.
Or maybe there is alternative viewpoint that justifies fair sampling assumption?
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