Spatially Resolved Hong Ou Mandel - "Coalescing" Photons

[Swamp Thing]

I'm reading this article https://www.osapublishing.org/ol/abstract.cfm?uri=ol-40-7-1540. It is a Hong-Ou-Mandel interferometer in which they can record exactly where each photon of a pair ends up, with a resolution of maybe a hundredth of the output port areas. So you see either two dots in the port A region or two dots in the port B region, but never one dot in port A and one dot in port B. The authors refer to this as "coalescing" of the two photons.

Now, considering this "bunching" or "coalescing" tendency of photons -- it seems to me that there should be a significant number of events where both dots are registered in the same pixel or in nearby pixels, as compared to the case where they are far apart. But in fact, the authors actually discard cases where the two events are recorded near to each other, because they say that there is a tendency for one photon to spuriously excite nearby pixels as a result of the photon multiplication technology that they use:

"During the experiment, we noticed that the photoelectron multiplication can trigger another avalanche in the neighboring channel, hence we had to reject the events where the distance between photons including both directions were smaller than twelve pixels of sCMOS detectors".​

So my question is, IF this technology problem could be solved, and IF we could then include near by pixel pairs and also include the case of two photons in one pixel, -- then would we notice a spatial bunching tendency as part of the ideal theoretical behavior?

 

[eljose79]

I can offer some insights and thoughts on this topic. First of all, the Hong-Ou-Mandel interferometer is a powerful tool for studying the quantum nature of light. It allows us to observe the behavior of individual photons and their interactions with each other.

In this particular case, the authors are specifically looking at the coalescing of two photons, meaning that they both end up in the same output port. This is a phenomenon that is predicted by quantum mechanics and has been observed in other experiments as well.

The authors mention that they have to discard cases where the two photons are recorded near each other due to a technology problem. This is a common issue in experimental research, where technical limitations can affect the results. It is important for scientists to acknowledge and address these limitations in order to accurately interpret their data.

If this technology problem could be solved and the near-by pixel pairs could be included, it is possible that we would see a spatial bunching tendency as part of the ideal theoretical behavior. However, it is also important to consider that other factors, such as the environment in which the experiment is conducted, could also influence the results.

In any case, further research and experimentation would be needed to fully understand the behavior of photons in this type of interferometer. It is also worth noting that the behavior of photons can be influenced by various factors, and it is not always possible to predict or control their interactions.

Overall, this article highlights the complex and fascinating nature of quantum phenomena and the challenges that scientists face in studying them. It is through continued research and advancements in technology that we can gain a deeper understanding of these fundamental particles and their behaviors.