Quantum Eraser: do entangled photons arrive at different moments?

[Leonardo Muzzi]

TL;DR Summary

In a Delayed Choice Quantum Eraser experiment, do we know if paired photons actually arrive at different moments in time?

Considering a Delayed Choice Quantum Eraser experiment such as the one in the picture above:

It is said that paired photons arriving at the detectors A,B,C,or D, reach the detectors after the entangled pair has reached the interference screen.

Are we actually able to measure the time interval between the photon reaching the screen and its entangled pair reaching one of the detectors? How is this measurement made?

If yes, what is the longest interval ever made between these two events?

 

[Nugatory]

The paper describing this experiment is here: https://arxiv.org/abs/quant-ph/9903047

Note the detector D0 and the coincidence counter circuitry. Whoever drew the image you posted left these out either because they didn't understand their importance or in a misguided attempt to simplify the experiment for non-specialists.