Frequency Tripling via Sum-Frequency Generation at the Nanoscale

High refractive index dielectric nanostructures can be exploited to enhance nonlinear optical processes via the strong light confinement by their resonant modes. The sensitive dependence of these modes on geometry and material composition offers ample opportunities for tailoring response system. Here we report sum-frequency generation (SFG) individual AlGaAs nanocylinders, pumped two pulsed beams at a telecommunication frequency, ?, its duplicate, 2?. Under such scheme, SFG 3? = ? + 2? is degenerate with third-harmonic (THG) seeded input thereby tripling frequency second-order permittivity ?(2), rather than ?(3) as in THG. concurrent detection THG enables us determine 7 × 10–20 m2/V2 comparing experiments numerical simulations based known value ?(2). We observe rich size- polarization-dependent behavior that gives appeal studied system key component miniaturized photonic devices.