Single band-edge states can trap light and function as high-quality optical feedback for microscale lasers and nanolasers. However, access to more than a single band-edge mode for nanolasing has not been possible because of limited cavity designs. Here, we describe how plasmonic superlattices—finite-arrays of nanoparticles (patches) grouped into microscale arrays—can support multiple band-edge modes capable of multi-modal nanolasing at programmed emission wavelengths and with large mode spacings. Different lasing modes show distinct input–output light behaviour and decay dynamics that can be tailored by nanoparticle size. By modelling the superlattice nanolasers with a four-level gain system and a time-domain approach, we reveal that the accumulation of population inversion at plasmonic hot spots can be spatially modulated by the diffractive coupling order of the patches. Moreover, we show that symmetry-broken superlattices can sustain switchable nanolasing between a single mode and multiple modes.

中文翻译：

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等离子体超晶格中受控多模态纳米激光的带边工程

单带边缘状态可以捕获光，并可以用作微型激光器和纳米激光器的高质量光反馈。然而，由于有限的腔体设计，不可能获得超过单个带边缘模式的纳米激光。在这里，我们描述了等离激元超晶格-纳米颗粒（斑块）的有限阵列（分组为微尺度阵列）-如何支持能够在编程的发射波长下以大模式间隔进行多模态纳米激光的多个带边缘模。不同的激光模式显示出不同的输入-输出光行为和衰减动力学，可以根据纳米粒子的大小进行调整。通过使用四级增益系统和时域方法对超晶格纳米激光进行建模，我们揭示等离子激元热点人口反转的积累可以通过补丁的衍射耦合顺序在空间上进行调节。此外，我们表明，对称性破裂的超晶格可以维持单模和多模之间的可切换纳米激光。