[8a-S2-1~11] 3.13 Silicon photonics, Photonics-electronics convergence, Optical control

11:15 AM - 11:30 AM JST(2:15 AM - 2:30 AM UTC)

[8a-S2-9] Experimental Demonstration of Low-Loss Thin-film LN Grating Couplers

〇Naoki Tahara¹, Shoji Hachuda¹, Shunsuke Sakamoto¹, Yuma Arawaka¹, Toshihiko Baba¹ (1.Yokohama Natl Univ)

Keywords:

TFLN,Grating Coupler

Thin-film lithium niobate (TFLN) grating couplers (GCs) were optimized using the covariance matrix adaptation evolution strategy (CMA-ES) to achieve efficient coupling between TFLN waveguides and single-mode optical fibers. The grating dimensions, positions, and fiber parameters were optimized on an X-cut 600-nm-thick TFLN platform, resulting in a simulated maximum coupling efficiency of −2.7 dB. The optimized devices were fabricated using electron-beam lithography and Ar ICP etching. Transmission measurements demonstrated a coupling efficiency better than −3.0 dB per GC.