Frequently the non-linear optical response of polar materials is explained using crystal-chemistry arguments based on microscopic dipoles which produce an electric polarization. How does one explain second harmonic generation (SHG) then in non-polar noncentrosymmetric materials?
Dr. Cammarata and Prof. Rondinelli with experimental collaborators at the University of Houston explain in their recent paper entitled, Microscopic Origins of Optical Second Harmonic Generation in Noncentrosymmetric–Nonpolar Materials, that both chiral structural distortions and the polarizability of cations within a material are the key features that must be understood to enhance the NLO light-matter interaction. With this understanding, a new telluromolybdate is predicted to be a high-performing SHG material, but remains to be synthesized. Any experimental takers?