An emergent need exists for solid state tunable coherent light emitters in the mid-infrared range for spectroscopy, sensing, and communication applications where current light sources are dominated by spontaneous emitters. This paper demonstrates a distinct class of coherent thermal emitters operating in the mid-infrared wavelength regime. The structure of the light source consists of a dielectric metasurface fabricated on a phononic substrate. In this study, we present the first implementation of off-Γ Friedrich–Wintgen bound states in the continuum at mid-infrared wavelengths suitable for developing the next generation of coherent light emitters. Numerical analysis of the emissivity spectrum reveals the interference of resonances leading to avoided crossings and the formation of Friedrich–Wintgen bound states in the radiation spectrum. Additionally, significant localized field enhancements are observed within the metasurface at operating wavelengths. The emissivity spectra measured by reflectivity and emission experiments exhibit temporally coherent emission peaks in the vicinity of the bound state in the continuum, the first such demonstration in the mid-infrared region for wavelengths longer than 7 µm. These results represent a new approach for significant advancement in realizing mid-infrared coherent light emitters with promising implications for future technologies.

中文翻译：

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基于连续体束缚态的相干发光超表面

对于当前光源以自发发射器为主的光谱、传感和通信应用，迫切需要中红外范围内的固态可调谐相干光发射器。本文展示了在中红外波长范围内工作的一类独特的相干热发射器。光源的结构由在声子基板上制造的介电超表面组成。在这项研究中，我们首次在中红外波长的连续谱中实现了离 Γ 弗里德里希-温特根束缚态，适合开发下一代相干光发射器。发射率谱的数值分析揭示了共振的干扰，导致辐射谱中避免交叉和弗里德里希-温特根束缚态的形成。此外，在工作波长下，超表面内观察到显着的局部场增强。通过反射率和发射实验测量的发射率光谱在连续谱中的束缚态附近表现出时间相干发射峰，这是在波长大于 7 µm 的中红外区域中首次出现此类演示。这些结果代表了一种在实现中红外相干光发射器方面取得重大进展的新方法，对未来技术具有广阔的前景。