Design, fabrication, and measurement of RF IDTs for efficient coupling to wavelength-scale structures in thin piezoelectric films

Transducers are designed and fabricated that produce a Gaussian acoustic beam in a 750 nm thick suspended aluminum nitride membrane. The properties of the acoustic beam formed by the transducer are studied by means of a scanning confocal balanced homodyne interferometer, which we use for Doppler vibrometery. We also study the RF transmission properties of the acoustic beams as they interact with sub-wavelength aperture waveguides.