Flamel

How would one calculate how the wavefunction spreads out again after the observation collapses it?

I'm talking about entangled states.

From what I understand, the rate of a wavefunction's spread after its collapse can be manipulated if one starts with particular states. How would one calculate this, specifically in the case of photons if the calculations are different from other particles?

Not yet that I'm aware of. I'm pulling the concept from a thought experiment where bombs are triggered to detonate via a similar mirror mechanism and half-silvered mirrors and the nature of light waves and observation can be used to determine if the bomb is a dud without triggering it. Is the exact scenario needed? Would the wavefunction spread rate and the size of the minimum uncertainty collapsed wavefunction be able to be determined in the hypothetical scenario where a CCD magically detected the photon without destroying it?

Perhaps I haven't been clear enough. There would be a series of nanoscopic mirrors each linked to pressure sensors sensitive enough to detect the impact of a photon. Upon reflection, the position is determined and the wavefunction collapses. At what rate then would the wavefunction spread out, and how small would the wavefunction be at minimum uncertainty?

For this scenario, we can imagine a very small, sensitive mirror that can tell when a photon reflects off of it due to the momentum it imparts.

Suppose that the position of a photon is measured such that the position Wavefunction collapses to minimum uncertainty without the photon being destroyed. At approximately what rate would the wavefunction spread out and approximately what size would the collapsed wavefunction be?