Fig. 4: Temporal aiming with monochromatic Gaussian beams under oblique incidence.
From: Temporal aiming
Similar to Fig. 3 but for oblique incidence. a, b Numerical results of the snapshot of the power-flow distribution and instantaneous Poynting vector (blue arrows) distributions for a Gaussian beam with a beam waist diameter D = 9λ before the change in εr (when εr1 = 10) at t = 30.2 T (t = t1−) and after the change in permittivity to \(\overline{\overline {\varepsilon _{r2}}}\) = [εr2x = 1, εr2z = 15] at t = 36.3 T (t > t1), respectively. c, d Numerical results of the snapshot of the power-flow distribution and instantaneous Poynting vector distributions using the same set-up, times and change in εr as in panels a, b but for a Gaussian beam with a beam waist diameter D = 2λ. As in Fig. 3, in all the numerical results, the incoming signal is switched off once the temporal boundary is induced at t = t1 to appreciate the effect of using a time-dependent εr(t) on a signal already present in the medium. Moreover, note that the scale bars for panels b, d were saturated from 0 to 0.8 to better appreciate the FW and BW waves produced at the temporal boundary
