2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/134423The main argument against the reality of the electromagnetic vacuum fluctuations is that they do not activate photon detectors. In order to meet this objection we propose a classical model of a photodetector which, in the simple case of a light signal with constant intensity, gives a counting rate which is a non-linear function of the intensity. For sufficiently large signal intensity, the counting rate is proportional to the intensity, in agreement with the standard quantum results, but there is a dark rate when the signal intensity is low.14 pages, no figuresQuantum Physicstext