Criticize diagram of delayed choice quantum eraser

[Strilanc]

I'm trying to create a simplified diagram of the delayed choice quantum eraser experiment (contrast with the confusing one on Wikipedia and the simplified one on some random site). Here's what I have so far:

Context that goes with the diagram: it is understood that an entangled pair of photons emerges from the top slit, the bottom slit, or a superposition thereof. One photon goes left while its entangled partner goes right.

I mainly want to know (a) if the diagram is confusing, and (b) if an oversimplification has removed crucial information that needs to be clarified or called out. For example, in the actual experiment the photons don't really go in opposite directions. Also the diagram omits any lenses. Is that confusing? Misleading? Is the essence still there?

 

[andrewkirk]

I think people will wonder why the idler photons going left are traveling at a non-right angle to the screen, and what that implies for the signal photon heading right.
That's the price that is paid for omitting the prisms and mirrors in the original Kim diagram ( or which the wiki version is a reasonable representation).

 

[Strilanc]

I think people will wonder why the idler photons going left are traveling at a non-right angle to the screen, and what that implies for the signal photon heading right.
That's the price that is paid for omitting the prisms and mirrors in the original Kim diagram ( or which the wiki version is a reasonable representation).

That's a good point. (Though I'm surprised you focused on that instead of the mystery of why one side is spherical waves while the other is straight paths.)

I was thinking of putting a yellow spark-flicker-bang over the slits, to show that's where the photons are emerging from. That might help. It would obscure the orientation of the slits (so "why not perpendicular?" might not occur as a thought in the first place), and could help indicate that something non-trivial is happening.

 

[Strilanc]

Here is an updated version:

And:

 

[Strilanc]

And now you can see them in context: http://algorithmicassertions.com/quantum/2016/01/07/Delayed-Choice-Quantum-Erasure.html