[Physics] Maximum light intensity

electromagnetic-radiationintensityluminosity;refractionvisible-light

From what I had learned and observed, every image (light per certain area,let it be cm^2 here) can be projected onto a small or large area without any natural obstruction from intensity. So, if light interacts by particle nature on impacting solidly then there must be a natural maximum light intensity per unit area right?
Please correct my logic if it heavily or small flawed.

Best Answer

I'll try to answer, though I only have superficial knowledge in this field.

For all practical purposes, you can assume that light does not interact with itself.

If you think that "light consists of photons", then, assuming photons don't interact with themselves, it is possible to pack any density of light/photons into a volume.

If you think that "light is a wave", you can use the the superposition principle to make a thought experiment of packing any number of identical light rays in some volume of space.

This doesn't work for very large light densities because of general relativity - then, light interacts with light by gravity. If this is true (no one knows for sure), then there is a maximal density of light, beyond which a black hole appears. This is explained in the linked question and answer. As far as I know, we are technologically very far from observing gravitational interaction between photons.

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