[16p-K309-1~10] 3.12 Semiconductor optical devices

1:30 PM - 1:45 PM JST(4:30 AM - 4:45 AM UTC)

[16p-K309-1] Structural Optimization of Thin-Film LNOI Waveguide Grating Couplers (Ⅲ)

〇Ryosei Kitahara¹, Ryoichi Yoshida¹, Shoji Hachuda¹, Naoki Tahara¹, Toshihiko Baba¹ (1.Yokohama Nat'l Univ.)

Keywords:

Thin-Film LNOI Waveguide,Grating Couplers,Optimization

The coupling efficiency of grating couplers for thin-film lithium niobate (TFLN) waveguides is low, in the 30% range, due to symmetrical top-bottom radiation and mode mismatch, making higher efficiency a challenge. In this study, an experiment without SiO2 cladding was assumed, with SiO2 on the bottom and air on the top. Such asymmetric cladding generally results in lower efficiency. Furthermore, the actual etching sidewall angle was precisely taken into account for optimization.