Photonic-tunneling experiments

Microwave transmission, in both the frequency and the time domain, through undersized waveguides, which corresponds to potential-barrier tunneling, was studied. The transmission properties inside the potential barriers are shown to be separable from the scattering contributions at the boundaries; no phase shift was found inside. Pulsed measurements in the time domain are used to obtain traversal-time values for opaque barriers. Furthermore, resonant-tunneling experiments through a double-barrier configuration have confirmed that the traversal time and the resonant-state lifetime are different physical entities.