A very simple (therefore strong) argument, grounded in the action reaction principle, predicts the existence of isolated quantum, de Broglie waves. In this article I propose an experimental set up able to detect these quantum waves. As far as quantum waves are associated to any kind of elementary particles, massive or massless, charged or neutral, etc., its character is probably gravitational, i.e., they are micro-gravitational waves. The quantum wave is isolated when a particle can follow two (or more) alternative paths which later on can rejoin and interfere. We know that the corpuscular particle follows one path while the wave follows both. This wave could perturb a laser beam, and this perturbation could be detected in a Mach-Zehnder interferometer.