Random scattering of light in disordered media is an intriguing phenomenon of fundamental relevance to various applications¹. Although techniques such as wavefront shaping and transmission matrix measurements^2,3 have enabled remarkable progress in advanced imaging concepts^{4,5,6,7,8,9,10,11}, the most successful strategy to obtain clear images through a disordered medium remains the filtering of ballistic light^12,13,14. Ballistic photons with a scattering-free propagation are, however, exponentially rare and no known method has been able to increase their proportion. To address these limitations, we introduce and experimentally implement a new set of optical states that we term scattering invariant modes, whose transmitted field pattern is the same, irrespective of whether they scatter through a disordered sample or propagate ballistically through a homogeneous medium. We observe scattering invariant modes that are only weakly attenuated in dense scattering media, and show in simulations that their correlations with the ballistic light can be used to improve imaging inside scattering materials.

无序介质中光的随机散射是一种与各种应用基本相关的有趣现象¹。尽管波前整形和传输矩阵测量等技术^2,3在先进的成像概念^{4,5,6,7,8,9,10,11}方面取得了显着进展，但通过无序介质获得清晰图像的最成功策略仍然存在弹道光的过滤^12,13,14. 然而，具有无散射传播的弹道光子是指数级罕见的，并且没有已知的方法能够增加它们的比例。为了解决这些限制，我们引入并通过实验实现了一组新的光学状态，我们称之为散射不变模式，其透射场模式是相同的，无论它们是通过无序样品散射还是通过均匀介质弹道传播。我们观察到在密集散射介质中仅弱衰减的散射不变模式，并在模拟中表明它们与弹道光的相关性可用于改善散射材料内部的成像。