Do photons emitted from different color filters leave varying size marks on a screen when fired

photonsvisible-light

I have read that photon "size" is proportion to wavelength, but I've also read that photon "size" isn't exactly a thing. So does this mean that different colors, which have different wavelengths and thus different "size" photons, will leave different size marks on a light sensitive screen when fired?

By "firing" photons, I mean the technology that results in a build up pattern of circular points, like here (although this one is with electrons):
https://www.youtube.com/watch?v=hv12oB_uyFs

And by different color filters, I mean placing different colored filters in front of a light source, like in this video:
https://www.youtube.com/watch?v=kcSYV8bJox8

So when you swap filter colors in front of whatever light source is being used to emit photons in a build up pattern experiment, do the circular dots that build up, have different sizes (or densities/intensities) dependent on the color of the filter used?

Or would it just be the build up pattern itself (like the interference pattern in a double slit experiment) that is different, and the individual build up marks themselves are all identical regardless of any colored filter that might be in front of the light?

Best Answer

The size of a photon means something entirely different than it would in classical physics. A photon is described by a wave function. From the wave function, you can calculate the probability of finding the photon at a particular position if you measure it. You measure it by interacting with it, which changes the photon.

One way a photon interacts when it hits a screen is to promote an electron in a single atom to a higher energy orbital. The photon is absorbed and ceases to exist. It does not matter how big the photon's wave function is. It will interact with just one atom this way.

Other ways of interacting can be more spread out. A mirror is a smooth metal surface. Conduction electrons in a metal do not stick to a single atom. They spread out. A photon interacts with the sea of spread out electrons. The result is a photon just like the incoming photon, but reflected away. This interaction is easiest to understand from a classical description. Classical light is an oscillating electromagnetic field. It causes surface electrons to vibrate, and the light is absorbed. A plane of vibrating electrons emit light. This creates the reflected photon.

For more about the nature of a photon, see How can a red light photon be different from a blue light photon?.

Also see Does the collapse of the wave function happen immediately everywhere?. This describe an electron, but it works the same for a photon.

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