넓은 청야각을 갖는 음향메타렌즈의 설계

Abstract

A metalens is an instrument that manipulates waves and has exhibited remarkable capabilities to date. However, an important hurdle arises due to the severe hampering of the angular reponses originating from coma and field curvature aberrations, which result in a loss of focusing ability. Herein, we provide an innovative blueprint by newly intorducing the notion of a wide field-of-hearing (FOH) metalens, designed particularly for cpaturing and focusing sound with decreased aberrations. Using an ultrathin metalens that satisfies both complete phase modulation and unitary transmission, we obtain an unprecedented wide FOH capability of approimately 140deg in angular range. Moreover, our metalnens features a remarkably short focal length, enabling ultracompact implementation by reducing the aperture-to-hearing plane distance. This is beneficial for space-efficient source-tracking sound sensing. Our strategy can be used across various platforms, potentially including energy harvesting, monitoring, imaging, and communication in auditory, ultrasonic, and submerged environments.