“…1-10 Different kinds of media, such as polymers, 2 organic liquids, 3 crystals, 4 glass ceramics, 5 nanostructured materials, 6,7 and glasses, [8][9][10][11][12] are currently engineered to possess large nonlinear responses. For instance, it is well known that the presence of heavy-metal ions often increases the nonlinear refractive index of a medium.…”