We demonstrate a collinear acousto-optic modulator in a suspended film of lithium niobate employing a high-confinement, wavelength-scale waveguide. By strongly confining the optical and mechanical waves, this modulator improves a figure-of-merit that accounts for both acousto-optic and electro-mechanical efficiency by orders of magnitude.


C. Sarabalis, R. Van Laer, R. Patel, Y. Dahmani, W. Jiang, F. Mayor, and A. Safavi-Naeini, “Acousto-optic modulation of a wavelength-scale waveguide,” Optica, vol. 8, no. 4, pp. 477–483, 2021, https://doi.org/10.1364/OPTICA.413401