Figure 1

Experimental setup. Light from a 532 nm laser is first split by a polarizing beam splitter. The ordinarily-polarized beam passes through a Mach-Zehnder interferometer (a) to induce a waveguide array in an SBN:75 crystal. The extraordinarily-polarized beam passes through a modified Mach-Zehnder interferometer (b) to create a Gaussian-on-background input shock profile. Light exiting the crystal is imaged into two CCD cameras, one for the intensity in position ($\mathbf{x}$) space, one for the power spectrum in momentum ($\mathbf{k}$) space (obtained by performing an optical Fourier transform). To excite a second-band Bloch background for a higher-band shock, the plane wave arm in (b) is blocked and the interferometer in (a) is partially polarized in the extraordinary direction.Reuse & Permissions

Figure 2

Linear transmission spectrum in the reduced Brillouin zone scheme, showing key propagation constants and field profiles of representative modes. Modes numbered 1 and 3 are the initial background $k$-vectors, and the arrows indicate the effect of defocusing nonlinearity.Reuse & Permissions

Figure 3

Output pictures of dispersive shock waves in homogeneous and lattice systems. Left column: intensity in position ($\mathbf{x}$) space; right column: power spectrum in momentum ($\mathbf{k}$) space. The left side of each panel shows experimental output pictures, while the right side shows cross sections from experiment (top) and beam propagation simulation (bottom). For a Gaussian-on-background input intensity ratio of $10:1$, the pictures show shock waves (a,b) in homogeneous system; (c,d) against fundamental, first-band background (modes $1+$); (e,f) against second-band, cosine background (mode 3). In (c–f), the period of the lattice is $30\mu \mathrm{m}$. Note that in (f), the first Bragg peaks have been saturated to allow visualization of the less-intense, higher-order modes.Reuse & Permissions

Figure 4

Output pictures of different initial intensity profiles in optical lattices. (a,b) Bright Gaussian hump with width $15\mu \mathrm{m}$, intensity ratio $1:1$ to the lattice; (c,d) plane background wave, with intensity ratio $1:10$ to the lattice; (e,f) cosine background wave, with intensity ratio $1:10$ to the lattice. The period of the lattice is $30\mu \mathrm{m}$. Left and right columns show intensity in position ($\mathbf{x}$) space and power spectrum in momentum ($\mathbf{k}$) space, respectively.Reuse & Permissions