Quantum optics is the study of the intrinsically quantum properties of light. During the second part of the 20th century experimental and theoretical progress developed together; nowadays quantum optics provides a testbed of many fundamental aspects of quantum mechanics such as coherence and quantum entanglement. Quantum optics helped trigger, both directly and indirectly, the birth of quantum technologies, whose aim is to harness non-classical quantum effects in applications from quantum key distribution to quantum computing. Quantum light remains at the heart of many of the most promising and potentially transformative quantum technologies. In this review, we celebrate the work of Sir Peter Knight and present an overview of the development of quantum optics and its impact on quantum technologies research. We describe the core theoretical tools developed to express and study the quantum properties of light, the key experimental approaches used to control, manipulate and measure such properties and their application in quantum simulation, and quantum computing.

中文翻译：

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从量子光学到量子技术

量子光学是研究光的内在量子特性。在 20 世纪下半叶，实验和理论进步共同发展；如今，量子光学为量子力学的许多基本方面提供了一个测试平台，例如相干性和量子纠缠。量子光学直接和间接地推动了量子技术的诞生，其目的是在从量子密钥分发到量子计算的应用中利用非经典量子效应。量子光仍然是许多最有前途和潜在变革性量子技术的核心。在这篇评论中，我们庆祝彼得·奈特爵士的工作，并概述了量子光学的发展及其对量子技术研究的影响。