Application of the Discontinuous Galerkin Time Domain Method in Nonlinear Nanoplasmonics

We describe an implementation of the Discontinuous Galerkin Time Domain (DGTD) method for massively parallel numerical simulations of the nonlinear optical response from metallic nanostructures. A Maxwell- Vlasov hydrodynamic model is used to account for the nonlinear effects in the motion of the free electrons in a metal. The model is applied to simulate the second-harmonic generation (SHG) from the golden gap nanoantennas with random surface rougness. The results show that surface defects break the symmetry of the structure and produce bright SHG hot spots on the surface of nanoantennas. This increases the far-field SHG intensity by orders of magnitude.