Superfluorescence (SF) is a unique quantum optics phenomenon arising from the assembly of self-organized and cooperatively coupled emitters. SF produces a short and intense burst of light, ideal for various applications in nanophotonics and optical computing. However, due to the prerequisite for cooperative emitter coupling, SF was conventionally observed in a Stokes-shifted manner under cryogenic conditions in limited systems (for example, atomic gases and perovskite-nanocrystal superlattices). Here we show that room-temperature anti-Stokes-shift SF is achieved in a few randomly assembled or in a single lanthanide-doped upconversion nanoparticle. Moreover, upconverted SF has a 10,000-fold accelerated nanosecond lifetime (τ = 46 ns of SF versus τ = 455.8 μs for normal upconversion luminescence), overcoming the slow decay of conventional upconversion systems. Therefore, the conceptual room-temperature anti-Stokes-shift SF not only lays the foundation for ultrafast upconversion but it also paves a straightforward way to a wide variety of applications that have been limited by the existing SF system.

超荧光（SF）是一种独特的量子光学现象，由自组织和协同耦合的发射器组装而成。SF 产生短暂而强烈的光爆发，非常适合纳米光子学和光学计算中的各种应用。然而，由于协同发射极耦合的先决条件，SF 通常在有限系统（例如，原子气体和钙钛矿-纳米晶体超晶格）的低温条件下以斯托克斯位移方式观察到。在这里，我们表明室温反斯托克斯位移 SF 是在一些随机组装或单个镧系元素掺杂的上转换纳米粒子中实现的。此外，上转换的 SF 具有 10,000 倍的加速纳秒寿命（τ  = 46 ns 的 SF 与τ = 455.8 μs（正常上转换发光），克服了传统上转换系统的缓慢衰减。因此，概念性的室温反斯托克斯位移 SF 不仅为超快上转换奠定了基础，而且还为受现有 SF 系统限制的各种应用铺平了直接的道路。