Far-field acoustic subwavelength imaging and edge detection based on spatial filtering and wave vector conversion
Far-field acoustic subwavelength imaging and edge detection based on spatial filtering and wave vector conversion
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DOI：
10.1038/s41467-018-08221-7
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发表时间：
2019-01-14
影响因子：
16.6
通讯作者：
Fang, Nicholas X.
中科院分区：
文献类型：
--
作者：
Ma, Chu;Kim, Seok;Fang, Nicholas X.
由于携带亚波长信息的倏逝场的损失，使得声成像的分辨率受到衍射极限的限制。目前大多数克服声学衍射极限的方法仍然是在物体的近场中进行的。在这里，我们展示了一个声学远场亚波长成像系统的设计和实验实现。我们的系统是基于波矢量滤波和转换的发射机在近场和空间对称的接收机在远场。通过调整发射/接收对的几何参数，可以分离不同的空间频带并将其投影到远场。此外，远场成像和边缘检测的亚波长目标的实验证明。该系统为远场亚波长波操纵带来了新的可能性，可进一步应用于医学成像、无损检测和声学通信。
The resolution of acoustic imaging suffers from diffraction limit due to the loss of evanescent field that carries subwavelength information. Most of the current methods for overcoming the diffraction limit in acoustics still operate in the near-field of the object. Here we demonstrate the design and experimental realization of an acoustic far-field subwavelength imaging system. Our system is based on wave vector filtering and conversion with a transmitter at the near-field and a spatially symmetrical receiver at the far-field. By tuning geometric parameters of the transmitting/receiving pair, different spatial frequency bands can be separated and projected to the far-field. Furthermore, far-field imaging and edge detection of subwavelength objects are experimentally demonstrated. The proposed system brings new possibilities for far-field subwavelength wave manipulation, which can be further applied to medical imaging, nondestructive testing, and acoustic communication.