In this study, a novel acoustic doublet meta-material lens has been designed and tested to demonstrate both a far-field focal point and ultra-long collimation characteristics past the Fresnel zone. The switching of the two behaviors can be adjusted by a simple linear mechanical translation of one of the lens units. The doublet lens can focus the sound wave beyond 38λ away from the experiment’s lens, which is farther than any existing ultrasonic transducer or meta-lenses lenses. In terms of collimating behavior, the doublet lens is a unique metamaterial lens that experimentally demonstrates a long and narrow collimating beam over 70λ. Besides the design and characterization, the meta-lens have been used to detect real objects, including inorganic and organic matter. A subwavelength spatial resolution has been demonstrated. The detection limit was 0.26λ in the monostatic setup and 0.62λ in a bistatic experimental setup. This lens demonstrates super-resolution detection capabilities at distances of 42λ and can enable ultrasonic diagnostics deep within a material or a biological tissue. The experimental performance of the doublet meta-material lens illustrated its potential to apply acoustic metamaterial elements in a practical imaging application, including the detection of biological tissues

在这项研究中，已经设计并测试了一种新型的双声超音速材料透镜，以证明经过菲涅耳区的远场焦点和超长准直特性。可以通过一个透镜单元的简单线性机械平移来调整两种行为的切换。该双合透镜可以聚焦声波超出38个λ从实验的透镜，这是比任何现有的超声换能器或间透镜透镜更远。在准直行为方面，双合透镜是，超过70实验演示了一个狭长准直光束的唯一超材料透镜λ。除了设计和表征外，超透镜还用于检测真实物体，包括无机物和有机物。已经证明了亚波长空间分辨率。检测限为0.26 λ在单基地设置和0.62 λ在收发分置的实验设置。该透镜在42的距离表明超分辨率检测能力λ，并且可以一材料或生物组织内深使超声诊断。双合超材料透镜的实验性能说明了其在实际成像应用（包括生物组织检测）中应用声学超材料元素的潜力。