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What light is and how to describe it has always been a central subject in physics. As our understanding has increased, so have our theories changed: geometrical optics, wave optics and quantum optics are increasingly sophisticated descriptions, each referring to a larger class of phenomena than its predecessor. But how exactly are these theories related? How and when wave optics reduces to geometric optics is a rather simple problem. Similarly, how quantum optics reduces to wave optics has also been considered to be a very simple business. It is not so. As we show here the classical limit of quantum optics is a far more complicated issue; it is in fact dramatically more involved and it requires a complete revision of all our intuitions. The revised intuitions can then serve as a guide to finding novel quantum effects.


This article was originally published in New Journal of Physics, volume 15, issue 9, in 2013. DOI: 10.1088/1367-2630/15/9/093006

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IOP Publishing Ltd and Deutsche Physikalische Gesellschaft

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Creative Commons License
This work is licensed under a Creative Commons Attribution 3.0 License.



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