Modern imaging technologies are widely based on classical principles of light or electromagnetic wave propagation. They can be remarkably sophisticated, with recent successes ranging from single-molecule microscopy to imaging far-distant galaxies. However, new imaging technologies based on quantum principles are gradually emerging. They can either surpass classical approaches or provide novel imaging capabilities that would not otherwise be possible. Here we provide an overview of the most recently developed quantum imaging systems, highlighting the nonclassical properties of sources, such as bright squeezed light, entangled photons and single-photon emitters that enable their functionality. We outline potential upcoming trends and the associated challenges, all driven by a central enquiry, which is to understand whether quantum light can make visible the invisible.

现代成像技术广泛基于光或电磁波传播的经典原理。它们非常复杂，最近在从单分子显微镜到遥远星系成像等领域取得了成功。然而，基于量子原理的新型成像技术正在逐渐涌现。它们要么可以超越经典方法，要么提供原本不可能实现的新颖成像功能。在这里，我们概述了最新开发的量子成像系统，重点介绍了光源的非经典特性，例如明亮的压缩光、纠缠光子和实现其功能的单光子发射器。我们概述了即将到来的潜在趋势和相关挑战，所有这些都是由一个中心调查驱动的，即了解量子光是否可以使可见变为不可见。