Figure 3a. A propagating wave packet in an undersized waveguide (from Barbero, Hernández-Figueroa and Recami [10] (reprinted with permission from assocpub@aps.org)

From

Apparent Superluminal Speeds in Evanescent Fields, Quantum Tunnelling and Quantum Entanglement

Arne Bergstrom

International Journal of Physics. 2015, 3(1), 40-44 doi:10.12691/ijp-3-1-7