Quantum sensing has become a broad field. It is generally related with the idea of using quantum resources to boost the performance of a number of practical tasks, including the radar-like detection of faint objects, the readout of information from optical memories, and the optical resolution of extremely close point-like sources. Here, we first focus on the basic tools behind quantum sensing, discussing the most recent and general formulations for the problems of quantum parameter estimation and hypothesis testing. With this basic background in hand, we then review emerging applications of quantum sensing in the photonic regime both from a theoretical and experimental point of view. Besides the state of the art, we also discuss open problems and potential next steps.

量子感测已经成为一个广阔的领域。它通常与使用量子资源来提高许多实际任务的性能有关，这些任务包括类似雷达的微弱物体检测，从光学存储器中读取信息以及非常接近点状的光学分辨率。资料来源。在这里，我们首先关注量子感测背后的基本工具，讨论有关量子参数估计和假设检验问题的最新和通用公式。掌握了这一基本背景之后，我们将从理论和实验的角度回顾了量子感测在光子领域中的新兴应用。除了最新的技术水平之外，我们还讨论了未解决的问题和潜在的后续步骤。