Integrated nonlinear photonics provides transformative capabilities for controlling, enhancing and manipulating material nonlinearities in miniaturized on-chip platforms. The extreme reduction of optical mode areas within subwavelength waveguides allows for large enhancements of light–matter interactions resulting in nonlinear phenomena at significantly lower optical powers than their fibre and free-space counterparts. The integration of nonlinear materials into nanophotonics has been instrumental in the practical implementation of emerging applications such as quantum information processing, high-speed optical communications, ultraprecise frequency metrology and spectroscopy. Since the early 2000s, the development of new fabrication methods combined with nanoscale design has led to tremendous improvements in the quality and integration capability of both traditional and new nonlinear material platforms. In this Review, we outline design principles to harness the potential of nonlinear materials on integrated platforms through improvements in waveguide loss, resonator design and dispersion engineering principles. We discuss how these tools have been used towards realizing several of the major goals of integrated nonlinear photonics such as broadband frequency conversion, frequency-comb generation, quantum light sources and nonlinear optical quantum logic gates.

集成非线性光子学为控制、增强和操纵微型片上平台中的材料非线性提供了变革性的能力。亚波长波导内光模面积的极大减少使得光与物质的相互作用大大增强，从而在比光纤和自由空间对应物低得多的光功率下产生非线性现象。非线性材料与纳米光子学的集成有助于量子信息处理、高速光通信、超精密频率计量和光谱学等新兴应用的实际实现。自2000年代初期以来，新制造方法与纳米级设计相结合的发展使得传统和新型非线性材料平台的质量和集成能力取得了巨大的进步。在这篇综述中，我们概述了通过改进波导损耗、谐振器设计和色散工程原理来利用集成平台上非线性材料潜力的设计原则。我们讨论如何使用这些工具来实现集成非线性光子学的几个主要目标，例如宽带频率转换、频率梳生成、量子光源和非线性光学量子逻辑门。