Figure 1

Cross sections of (2+1)D beam propagation under different initial conditions. (a) The intensity profile of the initial wave function (dotted red), and of the light inducing the trap potential. (b) Propagation of the beam in the presence of a wide barrier. (c) Linear tunneling of low-intensity beam [$\psi (0,0,0)=0.3$]. (d) Soliton tunneling from the potential trap [$\psi (0,0,0)=1.35$]. (e),(f) Soliton ejection at increasingly higher input intensities $\psi (0,0,0)=2,\psi (0,0,0)=3$, respectively.Reuse & Permissions

Figure 2

Experimental intensity photographs at the input plane of the sample. (a),(b) The intensity profile inducing the trap potential and its cross section. (c),(d) Total intensity at the input plane: sum of the intensities of the (ordinarily polarized) beam inducing the trap potential and of the (extraordinarily polarized) launched beam, for $|\psi (0,0,0){|}^2\approx 4$, and its cross section. The total intensity reflects the overall potential: linear + the nonlinear part induced by the launched beam.Reuse & Permissions

Figure 3

Experimental photographs of the intensity structure at the output face of the sample, under various conditions. The vertical line marks the maxima of the external barrier. (a) Linear propagation, displaying on-axis propagation in a homogeneous system. (b) Nonlinear propagation of the beam when the barrier is too wide to observe tunneling effects; the beam forms a soliton propagating on-axis within the trap. (c) Linear tunneling of a low power beam through a narrow barrier [$\psi (0,0,0)\approx 0.3$]. (d) Soliton tunneling: the power tunneled out of the trap forms a soliton moving away from the trap [$\psi (0,0,0)\approx 1$]. (e),(f) Soliton ejection at increasing power levels [$\psi (0,0,0)\approx 2$, $\psi (0,0,0)\approx 8$, respectively]. The higher the initial power, the earlier the soliton ejection process occurs.Reuse & Permissions

Figure 4

(a) Effective induced potential for different values of $\psi (0,0,0)$. Simulated propagation of a beam launched inside a potential trap with (b) $\psi (0,0,0)\approx 0.9{\psi }_{\mathrm{TH}}$, (c) $\psi (0,0,0)\approx {\psi }_{\mathrm{TH}}$, (d) $\psi (0,0,0)=1.1{\psi }_{\mathrm{TH}}$. (e) Experimentally measured (black circles) and numerically calculated (smooth blue line) values of the power ejected from the trap (normalized by the total power) vs amplitude of the launched beam, for near-threshold values.Reuse & Permissions