Impact of domain depth on SAW generation by acoustic superlattice transducers in 128deg YX-cut lithium niobate

Surface acoustic wave (SAW) generation on 128° YX acoustic superlattice has been investigated by considering the finite-depth of the domain created by the UV direct-domain writing. We found that bound and localized SAW will be generated when the domain depth of the ASL structure, underlying the transducer, is smaller and bigger than the lattice period, respectively. Efficient bound SAW can be achieved, provided the domain depth is 30 % of the lattice period.