稀土离子掺杂纳米颗粒具有稳定、窄带、多色的发光特性，相比量子点和染料分子，更不容易受到串扰、光闪烁、光漂白等效应的影响，因此受到广泛关注。然而，稀土离子的长荧光寿命（微秒至毫秒级）、低量子产率、弱荧光强度以及非定向发射等，限制了其在时间依赖纳米光子器件中的应用。等离激元纳腔耦合了光场和电子激发，有利于显著压缩荧光寿命、提高量子产率、增强上转换发光效率，并有效调控其发射方向。本文综述了纳腔调控稀土离子发光的有效途径及其相关研究进展，着重介绍了纳腔调控稀土离子产生亚50 ns超快上转换发光的工作，并对其在单光子源、量子通信和纳米激光器等方面的应用进行了展望。

Rare-earth-doped upconversion nanoparticles have attracted considerable attention because of their stable, narrowband, and multi-color luminescence, which features less crosstalk, photo-blinking, and photo-bleaching compared with quantum dots and organic dyes. However, rare-earth ions exhibit long luminescence decay times (ranging from microseconds to milliseconds), low quantum efficiency, weak luminescence intensity, and nondirectional far-field emission, restricting their application in time-dependent nanophotonic devices. Optical fields and electron excitations are coupled in plasmonic nanocavities, which is beneficial for significantly shortening the luminescence decay time, improving the quantum efficiency, enhancing the upconversion luminosity efficiency, and effectively controlling the emission direction. The paper reviews recent progress in nanocavity modulation of rare-earth ion luminescence, with a focus on the work of nanocavity modulation of rare-earth ions to achieve sub-50-ns ultrafast upconversion luminescence, and prospects for its applications in single-photon sources, quantum communication devices, and nanolasers.