I'm looking for direct references two specific double slit variations that have been performed.   All I can find are vague 2nd and 3rd hand accounts and references about these.  If anyone can help me, I'd sure appreciate it.

   1st: a double slit setup was sent to a bunch of different colleges. They each shot one photon through the apparatus onto a separate recording plate, then passed the setup on. When the plates were compiled there was an interference pattern with each photon knowing it's place in the overall pattern, independent of time.

2nd:  The double slit wave collapse.  I've read  that if the measurement that collapses the wave into a a particle pattern is placed after the photon has passed thru the slits you still apparently collapse the function back in time before the split and get a particle/point-like pattern. 

  Somebody asked about these on a public discourse chat. I told him I would ask around to check the veracity of the second claim. Thanks in advance.  I'm rather curious about these, myself. 

11 minutes ago, E.E. DS Avalon said:

   I'm looking for direct references two specific double slit variations that have been performed.   All I can find are vague 2nd and 3rd hand accounts and references about these.  If anyone can help me, I'd sure appreciate it.

   1st: a double slit setup was sent to a bunch of different colleges. They each shot one photon through the apparatus onto a separate recording plate, then passed the setup on. When the plates were compiled there was an interference pattern with each photon knowing it's place in the overall pattern, independent of time.

2nd:  The double slit wave collapse.  I've read  that if the measurement that collapses the wave into a a particle pattern is placed after the photon has passed thru the slits you still apparently collapse the function back in time before the split and get a particle/point-like pattern. 

  Somebody asked about these on a public discourse chat. I told him I would ask around to check the veracity of the second claim. Thanks in advance.  I'm rather curious about these, myself. 

Never heard about #1, but #2 sounds like a delayed-choice quantum eraser experiment

https://en.m.wikipedia.org/wiki/Delayed-choice_quantum_eraser