Implications of Low‐Refractive Mode Index on Nonlinear Optical Interactions

Abstract Despite ample experimental evidence that the so‐called epsilon‐near‐zero (ENZ) materials enable enhancement of nonlinear interactions in limited volumes materials, there is still a lot controversy about theoretical interpretation results search optimal and structural configurations. The performance depending on their refractive index compared direct simulations prove with indium‐tin oxide material regime low superior to ENZ terms third harmonic generation (THG) efficiency. It shown as rule for low‐index THG scales inversely proportional squared. Another advantage modes they satisfy phase‐matching conditions by default. As exemplified numerical simulations, silicon‐based photonic crystals can effectively produce waves, which be manipulated propagate any desired direction. Such an approach helps avoid unnecessary complexity on‐chip linear circuitry reduces potential sources losses unifying whole production chain implementation same material, e.g., silicon.