With the classic double slit experiment both space coordinates affect each other. With this time axis double slit experiment one has to ask if t1 affects t2 or

With the classic double slit experiment both space coordinates affect each other. With this time axis double slit experiment one has to ask if t1 affects t2 or if t2 also affects t1. The latter would raise a lot of questions. I don't understand the paper well enough to know which of these cases they are observing but I assume only the t1->t2 case? I'd appreciate if someone with more domain knowledge could enlighten. Edit: after more thought I guess it would make sense that two slits after each other in time show a change in wavelength if they are brought close enough together. Essentially the time separated slits act like a space separated double slit experiment wherin the slits are oriented on an axis parallel to the direction of the light path instead of at a perpendicular one. The wave like nature does not just expand in one dimension in space but all three and so there must be interference in the direction of travel. Do I have the right idea with this?