散射在光的成像过程中无法避免,传统的光学成像技术很难解决散射引起的光波前畸变及图像失真等问题。近年来,大量的研究成果表明充分利用散射效应的成像技术可以实现透过散射介质或复杂介质成像,且具有超分辨的特性。本文在介绍散射成像基本原理的基础上,重点介绍了透过散射介质成像方法以及相关技术的研究进展,分析了散射成像尚存在的问题,最后对散射成像未来的研究方向进行了展望。

While propagating inside the strongly scattering biological tissue, photons lose their incident directions beyond one transport mean free path (TMFP, ~1 millimeter (mm)), which makes it challenging to achieve optical focusing or clear imaging deep inside tissue. By manipulating many degrees of the incident optical wavefront, the latest optical wavefront engineering (WFE) technology compensates the wavefront distortions caused by the scattering media and thus is toward breaking this physical limit, bringing bright perspective to many applications deep inside tissue, e.g., high resolution functional/molecular imaging, optical excitation (optogenetics) and optical tweezers. However, inside the dynamic turbid media such as the biological tissue, the wavefront distortion is a fast and continuously changing process whose decorrelation rate is on timescales from milliseconds (ms) to microseconds (
s), or even faster. This requires that the WFE technology should be capable of beating this rapid process. In this review, we discuss the major challenges faced by the WFE technology due to the fast decorrelation of dynamic turbid media such as living tissue when achieving light focusing/imaging and summarize the research progress achieved to date to overcome these challenges.