Figure 3
From: Observation of Time Reversed Light Propagation by an Exchange of Eigenstates
Propagation along a defect with strength \({\phi }_{{\rm{defect}}}=\pi \). (a) The defect supports two bound modes showing a mutual beating. (b) Combined with the phase modulation in Eq. 7, where \(\phi \) is increased by \({\phi }_{0}=2\pi /20\,\,\) after every fourth time step, the band structure is continuously deformed (right panels). When the gap closes, the defect modes couple to the continuum. At \(m\approx 80\), when the band gap closes a second time the reversal of the temporal evolution starts, which efficiently restores the initial distribution. In both panels, the intensity \({|{u}_{n}^{m}|}^{2}+{|{v}_{n}^{m}|}^{2}\) in both loops is shown, where the initial pulse injected into the mesh lattice is normalized to one. For a better visibility of the propagation, a logarithmic color scaling is chosen. Below the propagations in (a,b) the initial intensity distribution \({|{u}_{n}^{0}|}^{2}+{|{v}_{n}^{0}|}^{2}\) (blue curve) and the final distribution \({|{u}_{n}^{179}|}^{2}+{|{v}_{n}^{179}|}^{2}\) (orange curve) at \(m=179\) are depicted.
