Experimental Realization of Second Harmonic Generation in a Fibonacci Optical Superlattice of LiTaO3

We have designed and fabricated a novel nonlinear optical superlattice of LiTa${\mathrm{O}}_3$ in which two antiparallel 180° domains building blocks A and B were arranged as a Fibonacci sequence. We measured the quasi-phase-matched second-harmonic spectrum of the superlattice. The second-harmonic blue, green, red, and infrared light generation, with energy conversion efficiencies of $\sim 5\%–20\%$, was demonstrated experimentally, which efficiencies are comparable with those of a periodic superlattice. Destruction of self-similarity and extinction phenomenon have also been observed in the spectrum. The experiment results are in good agreement with theory.