Riaud Antoine, Thomas Jean-Louis, Baudoin Michael, Bou Matar Olivier
Institut d'Electronique, de Microélectronique et Nanotechnologie (IEMN), LIA LICS, Université Lille 1 and EC Lille, CNRS UMR 8520, 59652 Villeneuve d'Ascq, France.
Sorbonne Universités, UPMC Univ Paris 06, CNRS UMR 7588, Institut des NanoSciences de Paris (INSP), F-75005 Paris, France.
Phys Rev E Stat Nonlin Soft Matter Phys. 2015 Dec;92(6):063201. doi: 10.1103/PhysRevE.92.063201. Epub 2015 Dec 1.
Despite their self-reconstruction properties in heterogeneous media, Bessel beams are known to degenerate when they are refracted from an isotropic to an anisotropic medium. In this paper, we study the converse situation wherein an anisotropic Bessel beam is refracted into an isotropic medium. It is shown that these anisotropic Bessel beams also degenerate, leading to confined vortical waves that may serve as localized particle trap for acoustical tweezers. The linear nature of this degeneration allows the three-dimensional control of this trap position by wavefront correction. Theory is confronted to experiments performed in the field of acoustics. A swirling surface acoustic wave is synthesized at the surface of a piezoelectric crystal by a microelectromechanical integrated system and radiated inside a miniature liquid vessel. The wavefront correction is operated with inverse filter technique. This work opens perspectives for contactless on-chip manipulation devices.
尽管贝塞尔光束在非均匀介质中具有自我重构特性，但众所周知，当它们从各向同性介质折射到各向异性介质时会退化。在本文中，我们研究相反的情况，即各向异性贝塞尔光束折射到各向同性介质中。结果表明，这些各向异性贝塞尔光束也会退化，产生受限涡旋波，可作为声镊的局部粒子陷阱。这种退化的线性特性使得通过波前校正可以对该陷阱位置进行三维控制。理论与声学领域进行的实验进行了对比。通过微机电集成系统在压电晶体表面合成涡旋表面声波，并在微型液体容器内辐射。波前校正采用逆滤波技术进行操作。这项工作为非接触式片上操纵装置开辟了前景。
