Optical waveguides are the key building block of optical fiber and photonic integrated circuit technology, which can benefit from active photonic manipulation to complement their passive guiding mechanisms. A number of emerging applications will require faster nanoscale waveguide circuits that produce stronger light-matter interactions and consume less power. Functionalities that rely on nonlinear optics are particularly attractive in terms of their femtosecond response times and terahertz bandwidth, but typically demand high powers or large footprints when using dielectrics alone. Plasmonic nanostructures have long promised to harness metals for truly nanoscale, energy-efficient nonlinear optics. Early excitement has settled into cautious optimism, and recent years have been marked by remarkable progress in enhancing a number of photonic circuit functions with nonlinear plasmonic waveguides across several application areas. This work presents an introductory review of nonlinear plasmonics in the context of guided-wave structures, followed by a comprehensive overview of related experiments and applications covering nonlinear light generation, all-optical signal processing, terahertz generation/detection, electro optics, quantum optics, and molecular sensing.

光波导是光纤和光子集成电路技术的关键组成部分，可以受益于主动光子操纵来补充其被动引导机制。许多新兴应用将需要更快的纳米级波导电路，以产生更强的光与物质相互作用并消耗更少的功率。依赖非线性光学的功能在飞秒响应时间和太赫兹带宽方面特别有吸引力，但在单独使用电介质时通常需要高功率或大占地面积。等离子体纳米结构长期以来一直致力于利用金属实现真正的纳米级、节能的非线性光学。早期的兴奋已经转变为谨慎的乐观态度，近年来在多个应用领域利用非线性等离子体波导增强许多光子电路功能方面取得了显着进展。这项工作介绍了导波结构背景下的非线性等离子体激元学，随后全面概述了相关实验和应用，涵盖非线性光生成、全光信号处理、太赫兹生成/检测、电光学、量子光学、和分子传感。