Optical imaging has had a central role in elucidating the underlying biological and physiological mechanisms in living specimens owing to its high spatial resolution, molecular specificity and minimal invasiveness. However, its working depth for in vivo imaging is extremely shallow, and thus reactions occurring deep inside living specimens remain out of reach. This problem originates primarily from multiple light scattering caused by the inhomogeneity of tissue obscuring the desired image information. Adaptive optical microscopy, which minimizes the effect of sample-induced aberrations, has to date been the most effective approach to addressing this problem, but its performance has plateaued because it can suppress only lower-order perturbations. To achieve an imaging depth beyond this conventional limit, there is increasing interest in exploiting the physics governing multiple light scattering. New approaches have emerged based on the deterministic measurement and/or control of multiple-scattered waves, rather than their stochastic and statistical treatment. In this Review, we provide an overview of recent developments in this area, with a focus on approaches that achieve a microscopic spatial resolution while remaining useful for in vivo imaging, and discuss their present limitations and future prospects.

光学成像由于其高的空间分辨率，分子特异性和最小的侵入性，在阐明活体标本的潜在生物学和生理机制中起着核心作用。但是，其用于体内成像的工作深度非常浅，因此，在活体标本内部深处发生的反应仍然遥不可及。该问题主要源于由于组织的不均匀性而导致的多次光散射，从而使所需的图像信息模糊不清。迄今为止，自适应光学显微镜使样品引起的像差的影响最小化，已成为解决此问题的最有效方法，但由于它只能抑制低阶扰动，因此其性能已达到稳定水平。为了获得超出此常规限​​制的成像深度，人们对利用控制多重光散射的物理学越来越感兴趣。基于对多散射波的确定性测量和/或控制，而不是其随机和统计处理，出现了新的方法。在这篇综述中，我们概述了该领域的最新发展，重点是在实现微观空间分辨率的同时仍可用于体内成像的方法，并讨论了它们目前的局限性和未来前景。