Imaging systems operating in the terahertz part of the electromagnetic spectrum are attractive due to their ability to penetrate many opaque materials and provide unique spectral signatures of various chemicals. However, the use of terahertz imagers in real-world applications has been limited by the slow speed, large size, high cost and complexity of present systems, largely due to the lack of suitable terahertz focal-plane array detectors. Here we report a terahertz focal-plane array that can directly provide the spatial amplitude and phase distributions, along with the ultrafast temporal and spectral information of an imaged object. It consists of a two-dimensional array of ~0.3 million plasmonic photoconductive nanoantennas optimized to rapidly detect broadband terahertz radiation with a high signal-to-noise ratio. We utilized the multispectral nature of the amplitude and phase data captured by these plasmonic nanoantennas to image different objects, including super-resolved etched patterns in a silicon substrate and defects in battery electrodes. By eliminating the need for raster scanning and spatial terahertz modulation, our terahertz focal-plane array offers more than a 1,000-fold increase in the imaging speed compared with the state of the art and potentially suits a broad range of applications in industrial inspection, security screening and medical diagnosis, among others.

在电磁波谱太赫兹部分运行的成像系统很有吸引力，因为它们能够穿透许多不透明材料并提供各种化学物质的独特光谱特征。然而，太赫兹成像仪在实际应用中的使用受到现有系统速度慢、尺寸大、成本高和复杂性的限制，这很大程度上是由于缺乏合适的太赫兹焦平面阵列探测器。在这里，我们报告了一种太赫兹焦平面阵列，它可以直接提供空间幅度和相位分布，以及成像物体的超快时间和光谱信息。它由约 30 万个等离子体光电导纳米天线组成的二维阵列组成，经过优化，可以快速检测具有高信噪比的宽带太赫兹辐射。我们利用这些等离子体纳米天线捕获的振幅和相位数据的多光谱性质来对不同的物体进行成像，包括硅基板中的超分辨蚀刻图案和电池电极中的缺陷。通过消除光栅扫描和空间太赫兹调制的需要，我们的太赫兹焦平面阵列与现有技术相比，成像速度提高了 1,000 倍以上，并可能适合工业检测、安全等领域的广泛应用筛查和医疗诊断等。