Intramodal Acousto-Optic Scattering of Opto-Piezomechanical Device on Aluminum Nitride

We propose an integrated acousto-optic device with compact interdigital transducers (IDTs) design on aluminum nitride (AlN) platform for intramodal acousto-optic modulation. The designed suspended AlN-based acousto-optic devices are fabricated, which achieves maximum −34 dB double-sideband scattering, 3-dB RF modulation bandwidth up to 100 MHz, and optical operational bandwidth wider than 25 nm with stimulating acoustic wave frequency of 5.07 GHz in merely 560 × 65 μm ² device footprint area. This device offers new opportunities for achieving efficient microwave-to-optical conversion for enhancing Brillouin lasers, nonreciprocal isolators and other multiple acousto-optic interaction applications.