My question is about the experiment in which detectors are used behind the slits to determine which slit the photon goes through. Specifically, it's about the detectors themselves. What I found is that these detectors are some kind of photoelectric detectors. My question is this. During the single-photon experiment, is the detector thought to interact with the light (for example, as in the photoelectric effect), and if not, how is it that the detector actually detects the passage of the photon, that is, without interacting with it?