Nonlinear optical conversion in anisotropic 1-D photonic crystal structures

摘要

We fabricate anisotropic porous silicon structures, which exhibit 1-D photonic crystal properties. Both second and third harmonics are generated from these structures. We observe a significant enhancement of nonlinear optical signals from nanoporous materials with respect to crystalline materials. These findings are attributed to the nanocrystalline structure of porous Si. The phase matching of nonlinear optical processes becomes possible in birefringent porous Si structures. The variation of symmetry of the nonlinear optical response from the surface of multilayered anisotropic structures is observed.