Second-harmonic generation in integrated nanosphere chains

The second-harmonic generation in a three-dimensional subwavelength photonic circuit consisting of spherical semiconductors with large second-order nonlinear susceptibility has been investigated by using a multiple-scattering method. The second-harmonic fields along a single chain, around a corner, and split at forked structures have been demonstrated using the three-dimensional confinement effects of subwavelength light. Our results show that the second-harmonic generations can be realized in the three-dimensional subwavelength photonic circuit and provide an alternative route for the design of integrated three-dimensional nonlinear devices.