ULTRA-THIN ACOUSTIC LENS FOR SUBWAVELENGTH FOCUSING IN MEGASONIC RANGE, AND DESIGN METHOD THEREFOR

摘要

The present invention relates to an ultra-thin acoustic lens for subwavelength focusing in a megasonic range, and a design method therefor. More specifically, the present invention relates to a super-oscillatory planar ultra-thin acoustic lens for subwavelength focusing in a megasonic range, which includes a plurality of concentric regions arranged in a concentric shape with reference to the center point, wherein the concentric regions include a plurality of sound insulation regions for insulating incident sound waves, and a plurality of transmission regions for transmitting sound waves, the sound insulation regions and the transmission regions being formed alternately in a radial direction from the center point so as to focus incident sound wave energy onto a subwavelength region. The acoustic lens has flat surfaces on both sides thereof respectively and has a plate shape having a constant thickness, and a layout, which is a radius of each of the plurality of sound insulation regions and transmission regions in the concentric regions, is determined by a topology optimization reverse design method.