CNRS-Université de Toulouse, UPS, Laboratoire Collisions, Agrégats Réactivité, IRSAMC, Toulouse F-31062, France.
Nat Commun. 2011 Aug 23;2:447. doi: 10.1038/ncomms1434.
Pulses of light propagating through multiply scattering media undergo complex spatial and temporal distortions to form the familiar speckle pattern. There is much current interest in both the fundamental properties of speckles and the challenge of spatially and temporally refocusing behind scattering media. Here we report on the spatially and temporally resolved measurement of a speckle field produced by the propagation of an ultrafast optical pulse through a thick strongly scattering medium. By shaping the temporal profile of the pulse using a spectral phase filter, we demonstrate the spatially localized temporal recompression of the output speckle to the Fourier-limit duration, offering an optical analogue to time-reversal experiments in the acoustic regime. This approach shows that a multiply scattering medium can be put to profit for light manipulation at the femtosecond scale, and has a diverse range of potential applications that includes quantum control, biological imaging and photonics.
脉冲光在多次散射介质中传播会经历复杂的空间和时间扭曲，形成我们熟悉的散斑模式。目前人们对散斑的基本特性以及在散射介质后实现空间和时间聚焦的挑战都非常感兴趣。在这里，我们报告了通过传播超快光脉冲穿过厚的强散射介质产生的散斑场的空间和时间分辨测量。通过使用光谱相位滤波器对脉冲的时间分布进行整形，我们演示了输出散斑的空间局域时间压缩到傅里叶极限持续时间，这为声波反转实验提供了光学模拟。这种方法表明，多次散射介质可以在飞秒尺度上用于光的操控，并具有广泛的潜在应用，包括量子控制、生物成像和光子学。
