Thermoelectrically-coupled nanoantennas (TECNAs)—nanoantennas that use the Seebeck effect to detect radiation—are a promising modality for spectrally resolved detection in the infrared. By tailoring the geometry of a nanoantenna coupled to a micro-cavity, their responsivity and spectral selectivity can be carefully designed. However, to date no measurements have directly established the spectral response of these detectors over a large frequency span in the infrared regime, particularly from 2 μm to 20 μm. In this work, we provide a comprehensive analysis of the spectral selectivity of TECNAs operating within the mid- and long-wave infrared (MWIR and LWIR) regions. We engineer arrays of detectors at 5.5 μm, 10.6 μm, and 14 μm, and we verify their selectivity using polarization-dependent Fourier-transform infrared spectroscopy (FTIR). We also show that the response can be tailored using a combination of antenna and cavity design. Our results not only underscore the potential of TECNAs in advancing sensing applications within the MWIR and LWIR domains, but also offer a promising direction for enhancing other detector modalities.

中文翻译：

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热电耦合纳米天线光谱响应度的宽带表征

热电耦合纳米天线 (TECNA)——利用塞贝克效应来检测辐射的纳米天线——是一种很有前景的红外光谱分辨检测方式。通过定制与微腔耦合的纳米天线的几何形状，可以仔细设计它们的响应度和光谱选择性。然而，迄今为止，还没有测量直接确定这些探测器在红外范围内的大频率范围内的光谱响应，特别是从 2 μm 到 20 μm。在这项工作中，我们对中波和长波红外（MWIR 和 LWIR）区域内工作的 TECNA 的光谱选择性进行了全面分析。我们设计了 5.5 μm、10.6 μm 和 14 μm 的探测器阵列，并使用偏振相关的傅里​​叶变换红外光谱 (FTIR) 验证了它们的选择性。我们还表明，可以使用天线和腔体设计的组合来定制响应。我们的结果不仅强调了 TECNA 在推进 MWIR 和 LWIR 领域传感应用方面的潜力，而且还为增强其他探测器模式提供了有希望的方向。