Second-harmonic generation in dielectric nanoparticles with different symmetries

In this work we study second-harmonic generation of a monocrystalline nanoparticle with a noncentrosymmetric crystalline lattice. It was shown that breaking the symmetry of the nanoparticle’s shape can significantly affect the second-harmonic radiation pattern. We propose a method for explaining and predicting the generated field for arbitrary nanoparticles and provide selection rules for nanoparticles with several different symmetries.