Are unexpected bulk waves produced by surface wave transducers?

Abstract

It was recently reported that a surface wave transducer could produce a beam of bulk waves whose tangential wave number was twice the fundamental wave number of the transducer; the wave numbers in the transducer's electric field are odd multiples of the fundamental. In this investigation it is found that the extra beam comes from mode conversion of rays reflected at the ends of the sample; the beam is not directly generated by the transducer.