Nonlinear frequency conversion with all-dielectric nanoantennas (Conference Presentation)

Dielectric nanoantennas and metasurfaces have proven to be able to manipulate the wavefront of incoming waves with high transmission efficiency. The important next question is: Can they enable enhanced interaction with the light to transform its colour or to be able to control one light beam with another? Here we show how a dielectric nano-resonator of subwavelength size can enable enhanced light matter interaction for efficient nonlinear frequency conversion. In particular, we show how AlGaAs or silicon nanoantennas can enhance second and third harmonic generation, respectively. Importantly, by controlling the size of the antennas, we can achieve control of directionality and polarisation state of the emission of harmonics. Our results open novel applications in ultra-thin light sources, light switches and modulators, ultra-fast displays, and other nonlinear optical metadevices based on low loss subwavelength dielectric resonant nanoparticles.