论文标题
宽带声学准直并使用降低的畸变声音luneburg镜头进行聚焦
Broadband Acoustic Collimation and Focusing using Reduced Aberration Acoustic Luneburg Lens
论文作者
论文摘要
声学伦尼堡镜头是一种对称梯度指数镜头，其折射率从中心向外表面径向降低。它可以用来用准直和聚焦功能来操纵声波传播。然而，先前研究的声学伦尼堡镜头仅在可听见的频率范围从1 kHz到7 kHz或40 kHz的单个超声波频率。此外，在先前的研究中，高频的声学伦斯堡镜头不是全向的。此外，到目前为止，还没有实现3D声学伦斯堡镜头的模拟和实验测试。在本文中，提出了用于宽带和全向声学准则的实际减少声音Luneburg镜头（RAALL），并以减少的畸变聚焦。射线追踪技术表明，与传统的修改原声Luneburg镜头相比，Raall可以实现更好的声学焦点。随后，通过增材制造技术设计和制造了两种RAALL型号：2D版本和3D版本。在理论上，数值和实验上，对2D和3D镜头都证明了超声波的准直表和焦点性能，并验证了它们的宽带和全向特性。
Acoustic Luneburg lens is a symmetric gradient-index lens with a refractive index decreasing radially from the centre to the outer surface. It can be used to manipulate acoustic wave propagation with collimation and focusing capabilities. However, previously studied acoustic Luneburg lens works only at audible frequency ranges from 1 kHz to 7 kHz, or at a single ultrasonic frequency of 40 kHz. In addition, the acoustic Luneburg lens at high frequency is not omnidirectional in the previous researches. Furthermore, there is no realization of simulation and experimental testing of 3D acoustic Luneburg lens until now. In this paper, a practical reduced aberration acoustic Luneburg lens (RAALL) are proposed for broadband and omnidirectional acoustic collimation and focusing with reduced aberrations. Ray tracing technique shows that RAALL can achieve a better acoustic focusing compared with traditional modified acoustic Luneburg lens. Following that, two models of RAALL are designed and fabricated through additive manufacturing technology: a 2D version and a 3D version. Collimation and focusing performances of the ultrasonic waves are theoretically, numerically and experimentally demonstrated for both 2D and 3D lenses, and their broadband and omnidirectional characteristics are verified.
