What is the behavior of photons inside glass?

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SUMMARY

Photons exist within homogeneous, linear, transparent materials like glass when a monochromatic laser beam is directed normally at its surface. They are not replaced by polaritons or other exotic entities. According to classical theory, the speed of photons in glass is given by the equation v = c/n, where n is the refractive index. Quantum theory aligns with this, suggesting that photons effectively travel at a reduced speed within the medium.

PREREQUISITES
  • Understanding of classical optics and the behavior of light.
  • Familiarity with the concept of refractive index (n).
  • Basic knowledge of quantum electrodynamics (QED).
  • Awareness of the properties of monochromatic laser beams.
NEXT STEPS
  • Study the principles of classical optics, focusing on refraction and the speed of light in different media.
  • Explore quantum electrodynamics (QED) and its implications for photon behavior in materials.
  • Investigate the concept of polaritons and their relationship to light in transparent materials.
  • Learn about experimental methods to measure the speed of light in various media, including glass.
USEFUL FOR

Physicists, optical engineers, and students studying optics and quantum mechanics will benefit from this discussion, particularly those interested in the behavior of light in different materials.

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TL;DR
Do photons really exist in glass?
Which speed do they have there?
I'm aware of the numerous threads on the subject "light inside glass" there have been in the past, in case you will indicate me an appropriate one, but I haven't been able to find a clear answer to the questions:

1) Do photons really exist inside a (homogeneous, linear, transparent, refracting index n) material as glass, when, e.g., a monochromatic laser beam of wavelength λ is directed normally on its surface, or are they replaced by more "exotic" objects as "polaritons", etc?

2) If they exists and assuming they are not "absorbed and then emitted again after some delay", which speed do they have? I know classical theory shows that v = c/n, and I've read Feynman's QED ("it's as if photons would go through it with a reduced speed" or something alike) but what does quantum theory predicts of their actual speed?

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