Engineering nonlinear optics via metallo-semiconductor nanostructures

M. RAHMANI; H. AOUANI; G. GRINBLAT; M. NAVARRO-CÍA; E. CORTÉS; M. CALDAROLA; A.V. BRAGAS; S. A. MAIER

Simposio; Materials for the 21st century; 2015

The unbeatable speed of light gives unmatched information capacity leaving no doubt that light is the ultimate means of conveying information. But in today's technology, optical and electric signals have to be converted between each other many times, which introduces delays and additional power consumption. Nonlinear optics holds a great potential to circumvent these current limitations by eliminating the need for electronics, whereby light is directly controlled by light. It is at the heart of modern photonic functionalities, including diversifying laser systems, light-material interactions and information technology. Currently, nonlinear optical interactions are generally based on large anisotropic transparent crystals, which are not compatible with the size requirements of photonic and optoelectronic systems. Recent studies have revealed the potential of nanophotonics to address this issue via the artificially induced nonlinear responses in certain nanostructures. This is possible because nanostructures are capable of squeezing light fields into volumes orders of magnitude smaller than the diffraction limit of light. Metallic nanoparticles can exhibit extremely high optical nonlinearity due to the strong local field enhancement and the intrinsically high non-linearity of the metals used. However, since metallic structures absorb light, they tend to have a relatively low heat resistance to high power lasers. This disadvantage together with weak penetration of the exciting fields into the metal means conversion efficiency rates remain low, which could be key limiting factors to nonlinear optics at the nanoscale. In this talk, smart hybridisations of metals, dielectrics and semiconductors will be discussed to reveal the high potential of material engineering in this respect that can minimise energy losses and maximise conversion efficiency in novel nonlinear nanodevices on-chip, simultaneously.