Science Daily May 14, 2024
An important hurdle for using metalenses for manipulating waves is due to the severe hampering of the angular response originating from coma and field curvature aberrations, which result in a loss of focusing ability. Researchers in South Korea developed a blueprint by introducing the notion of a wide field-of-hearing (FOH) metalens, designed particularly for capturing and focusing sound with decreased aberrations. Employing an aberration-free planar-thin metalens that leverages perfect acoustic symmetry conversion, they experimentally realized a robust wide FOH capability of approximately 140 deg. in angular range. The metalens featured a relatively short focal length, enabling compact implementation by reducing the aperture-to-hearing plane distance which was beneficial for space-efficient source-tracking sound sensing. According to the researchers their strategy can be used across various platforms, potentially including energy harvesting, monitoring, imaging, and communication in auditory, ultrasonic, and submerged environments… read more. Open Access TECHNICAL ARTICLEÂ
Principle of a wide field-of-hearing system. Credit: Nature Communications, volume 15, Article number: 3044, April 8, 2024