Nonlinear plasmonics in eutectic composites: second harmonic generation and two-photon luminescence in a volumetric Bi2O3-Ag metamaterial

The nonlinear optical effect of second harmonic generation can be very strong when originating from nanoplasmonic structures, due to enhancement of the surrounding material’s intrinsic nonlinear optical properties or due to its occurrence as a result of the plasmonic structure. However, manufacturing of large-scale three dimensional nanoplasmonic structures s still a challenge. Here, we demonstrate the two-photon luminescence and second-harmonic generation in a Bi2O3-Ag eutectic-based metamaterial exhibiting a hierarchic structure of nano- and micro-sized silver precipitates. The investigations employed a microscope system combined with polarimetric analysis. It appears that the second-harmonic-generation arises from the silver plasmonic structure rather than from the nonlinear effects of the bismuth oxide matrix. Both quadrupolar and dipolar modes of polarization are observed.