The guiding and transport of energy, for example, of electromagnetic waves, underpins many modern technologies, ranging from long-distance optical fibre telecommunications to on-chip optical processors. Traditionally, a mechanism is required that exponentially localizes the waves or particles in the confinement region, such as total internal reflection at a boundary. Here we introduce a waveguiding mechanism that relies on a different origin for the exponential confinement and that arises owing to the physics of diffusion. We demonstrate this concept using light and show that the photon density can propagate as a guided mode along a core structure embedded in a scattering opaque material, enhancing light transmission by orders of magnitude and along non-trivial, such as curved, trajectories. This waveguiding mechanism can also occur naturally, for example, in the cerebrospinal fluid surrounding the brain and along tendons in the human body, and is to be expected in other systems that follow the same physics such as neutron diffusion.

能量的引导和传输，例如电磁波，是许多现代技术的基础，从长距离光纤电信到片上光处理器。传统上，需要一种机制，使波或粒子在约束区域中呈指数级定位，例如边界处的全内反射。在这里，我们介绍了一种波导机制，它依赖于指数限制的不同原点，并且是由于扩散物理学而产生的。我们用光来演示这个概念，并表明光子密度可以作为引导模式沿着嵌入散射不透明材料的核心结构传播，从而以数量级的方式和沿着非平凡的轨迹（例如弯曲的轨迹）增强光传输。这种波导机制也可以自然发生，例如，在大脑周围的脑脊液和人体的肌腱中，并且在遵循相同物理学（如中子扩散）的其他系统中是可以预期的。