EFFICIENT MID-INFRARED ACOUSTO-OPTIC MODULATION IN SILICON PHOTONIC DEVICES USING LITHIUM NIOBATE

The acousto-optic interaction in silicon photonics remains underutilized due to the absence of intrinsic piezoelectricity needed for efficient acoustic wave excitation, despite the maturity of silicon in large-scale photonic integrated circuits. In this work, we present a distinctive acousto-optic scheme that complements standard silicon photonics by heterogeneously integrating piezoelectric lithium niobate through micro-transfer printing. Leveraging lithium niobate as an acoustic pump to exploit the superior photoelastic properties of silicon, we demonstrate an optical modulation figure-of-merit of V pi L similar to 0.496 V.cm at a mid-infrared wavelength of similar to 3.8 mu m.