Study of Third Harmonic Generation From Thin Gradient HfxAlyOz Layers

Third harmonic generation (THG) from multiple thin layer structures has proven its capability to reach conversion efficiencies up to the percentage level [1] , becoming an interesting alternative to the cascaded third harmonic generation. However, such multi-layer structures need to be carefully optimized by computer algorithms. Here, we present a study of a single amorphous Hf x Al y O z layer with varying thickness. The advantage of ternary mixture materials such as Hf x Al y O z is the tunability of the bandgap, which directly influences the nonlinear susceptibility χ (3) . In comparison to previous works, where only layers of specific thickness or theoretical models were studied [2] , [3] , we present both, continuous experimental measurements and theoretical studies of the same sample.