Efficient Second Harmonic Generation of Diced Ridge Waveguides Based on Carbon Ion-Irradiated Periodically Poled LiNbO3

In this study, mechanically defined ridge waveguides were fabricated based on a planar periodically poled LiNbO
₃
waveguide formed by swift carbon ion irradiation. The second harmonic generation within the telecommunication band was demonstrated in these ridges. A normalized conversion efficiency as high as 77.9%/(W · cm
²
) was realized. The effect of the thermal annealing process on the quasi-phase-matching was also investigated.