Can 1D Cavities Explain Free Space Physics in EM-Field Quantization?

[Niles]

Hi

In all the books I've read on quantization of the EM-field, they do it 2 times: First they do it for a 1D cavity with no sources, which yields single-mode fields. Then they do it for free space with no sources, which yields multi-mode fields. I can't see the connection between these two setups. Somehow the physics of free space can be expressed by 1D cavities?


Niles.

 

[A. Neumaier]

Hi

In all the books I've read on quantization of the EM-field, they do it 2 times: First they do it for a 1D cavity with no sources, which yields single-mode fields. Then they do it for free space with no sources, which yields multi-mode fields. I can't see the connection between these two setups. Somehow the physics of free space can be expressed by 1D cavities?

No. The cavity case is just a warm-up exercise for the more complex full thing, to demonstrate how the machinery works.