Where does photon interference happen

In summary, the conversation discusses the concept of photon interference in the context of the Mach-Zehnder interferometer experiment. The first link provided suggests that in ideal conditions, no photons are detected at the second detector. However, a second experiment shows that interference is observed after a compensation process takes place. The discussion also mentions using photon pairs from a downconversion process and the difference between the HOM and SA experiments. Ultimately, the validity of extending conclusions from the modified SA experiment to the HOM experiment is questioned.
  • #1
zonde
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If we look at http://en.wikipedia.org/wiki/Mach%E2%80%93Zehnder_interferometer" [Broken] I think it's fair to say that any interpretation of QM says that there are appear no photons (in idealized case) at detector 2 as there are no detections. Basically that means that photon interference takes place at beam splitter.

As I see this approach conflicts with results of this experiment:
http://physics.nist.gov/Divisions/Div844/publications/migdall/psm96_twophoton_interference.pdf" [Broken]
where interference is observed after "postponed compensation" that takes place after beam splitter.

To make reasoning more straightforward let's say we use photon pair from donwconversion process where signaling photon goes through interferometer but idler is detected just for tracking purposes. So the setup is like this:
2j2b774.jpg

Will we see 100% coincident detections between Di and D2 with ideal detectors and ideal source (all photons are paired up)?
 
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  • #3
Here are valid links in place of those broken ones:
https://en.wikipedia.org/wiki/Mach-Zehnder_interferometer
https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.77.1917
And another similar paper https://arxiv.org/abs/quant-ph/0304030

These two-photon interference experiments demonstrate the passive role of first beamsplitter in SA type experiment but they extend these results to HOM experiment and claim that in case of HOM experiments beamsplitter has passive role as well.
In my question I was relying on correctness of this conclusion but my insight on the topic is that this conclusion is just wrong. HOM and SA experiments are very different despite some similarities in setup so that conclusions from modified SA experiment can not be extended to HOM experiment.
 
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1. What is photon interference?

Photon interference is a phenomenon that occurs when two or more light waves interact with each other and produce a new wave pattern. This interaction can result in either constructive or destructive interference, which can affect the intensity and direction of the light waves.

2. Where does photon interference happen?

Photon interference can happen anywhere that light waves can interact with each other. This includes areas such as thin films, diffraction gratings, and double-slit setups. Interference can also occur in everyday objects like soap bubbles and oil slicks.

3. What causes photon interference?

Photon interference is caused by the superposition of two or more light waves. This means that the waves are overlapping and their amplitudes are either adding or subtracting from each other. The resulting wave pattern is determined by the phase difference between the waves.

4. How does photon interference affect light waves?

Photon interference can have various effects on light waves. In constructive interference, the waves add together and result in a bright spot or a higher intensity of light. In destructive interference, the waves cancel each other out and result in a dark spot or a lower intensity of light. This can also affect the direction of the light waves, causing them to spread out or narrow in certain areas.

5. Why is photon interference important?

Photon interference plays a crucial role in many aspects of modern technology and science. It is used in fields such as optics, telecommunications, and quantum mechanics. By studying and understanding photon interference, scientists can gain a deeper understanding of light and its behavior, leading to advancements in various industries and fields of study.

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