Abstract: dielectric superlattice is a type of material with an ordered microstructure. A series of results in this field have been obtained by our research group in Nanjing University. We proposed the theory of multiple quasi-phase-matching (QPM), developed all-solid-state lasers operating at multi-frequencies as well as white-light lasers, discovered a QPM enhanced optical scattering effect, and a new mechanism for optical bistability. We have also studied piezoelectric ultrasonic excitation and prepared bulk prototype ultrasonic devices working at frequencies from several hundreds megahertz to a few gigahertz, discovered the strong coupling between superlattice vibrations and microwaves, and investigated the excitation and propagation of polaritons.