Transient total reflection and transient evanescent wave

Abstract

The total reflection of a steady plan wave is well known. The transmitted wave is an evanescent wave that propagates along one direction and evanesces along a direction perpendicular to the propagation direction. Evanescent waves also appear in many other acoustic problems, such as the surface wave along a free boundary of a solid medium. In this report, the total reflections with different incident waves are studied, including an incident beam with a limited width, an incident pulse wave with a limited duration, and an incident bulletlike wave package. These incident waves are represented by superposition of plane waves based on the angle spectrum synthesis. Their transmitted wave, therefore, can be synthesized from the transmitted waves of the plane incident wave. Snapshots of the acoustic field are presented that show the procedure of the interaction of the incident wave with the interface of the media. [Work supported by National Natural Science Fundation of China, No. 10534040.]