Figure 3b. The same wave packet as in Figure 3a with the same time scale but with the amplitude scale enlarged by a factor of 104, showing the tiny Sommerfeld precursor at t0 preceding the somewhat larger Brillouin precursor at t1 before the bulk of the wave packet arrives [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