Exploiting disorder for perfect focusing
Exploiting disorder for perfect focusing
复制标题
DOI：
10.1038/nphoton.2010.3
复制
发表时间：
2010-05-01
期刊：
影响因子：
35
通讯作者：
Mosk, A. P.
中科院分区：
文献类型：
--
作者：
Vellekoop, I. M.;Lagendijk, A.;Mosk, A. P.
光学显微镜和操作方法依赖于将光聚焦到小体积的能力。然而，在诸如生物组织之类的非均匀介质中，光会从聚焦光束中散射出去。无序散射被认为从根本上限制了光学方法的分辨率和穿透深度（1-3）。在这里，我们在一个光学实验中证明，散射可以用来提高而不是降低焦点的清晰度。由此产生的焦点甚至比透明介质中的焦点更清晰。利用透镜后介质的散射，光被聚焦到一个比透镜衍射极限小十倍的点上。我们的方法是光学等效的非常成功的方法，以提高超声，无线电波和微波的分辨率和通信带宽（4-6）。我们使用空间波前整形获得的结果适用于通过散射物质进行聚焦的所有相干方法，包括相位共轭(7)和时间反转(4)。
Optical microscopy and manipulation methods rely on the ability to focus light to a small volume. However, in inhomogeneous media such as biological tissue, light is scattered out of the focusing beam. Disordered scattering is thought to fundamentally limit the resolution and penetration depth of optical methods(1-3). Here we demonstrate, in an optical experiment, that scattering can be used to improve, rather than deteriorate, the sharpness of the focus. The resulting focus is even sharper than that in a transparent medium. By using scattering in the medium behind a lens, light was focused to a spot ten times smaller than the diffraction limit of that lens. Our method is the optical equivalent of highly successful methods for improving the resolution and communication bandwidth of ultrasound, radio waves and microwaves(4-6). Our results, obtained using spatial wavefront shaping, apply to all coherent methods for focusing through scattering matter, including phase conjugation(7) and time-reversal(4).