Real-time video-rate passive terahertz imaging systems are highly demanded for practical applications, especially in security checking. Here, we demonstrate a passive video-rate terahertz human body imaging system, which was mainly consisted of a scanning module, a quasi-optical lens, a calibration module and a one-dimensional terahertz detector array. The terahertz waves radiated from human bodies in front of the imager can transmit through a terahertz window into the imager, and were reflected by the scanning module, and then focused on the detector array by the quasi-optical lens. A calibration module was also designed to calibrate the terahertz detectors in real-time without disturbing the imaging process. In combination of the scanning module with the detector array, the imager can obtain a full image of a human body standing at a distance of 1.5 m in front of the imager with a resolution of 1.5 cm and a frame rate of 10 fps. The imaging system can discover suspected dangerous items carried on the human body such as metals, ceramics, powders and liquids. Furthermore, an intelligent terahertz imaging algorithm employing convolutional neural network was also successfully realized based on the terahertz images produced by this system to improve the image quality and mark the detected items automatically. We believe our real-time video-rate terahertz imaging techniques and systems not only have great values for further inspiring developing terahertz imaging systems but also can accelerate the terahertz technology towards more practical applications.

中文翻译：

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用于安全应用的具有实时校准功能的无源视频速率太赫兹人体成像仪

实时视频速率无源太赫兹成像系统在实际应用中的需求量很大，尤其是在安全检查中。在这里，我们展示了一种无源视频速率太赫兹人体成像系统，该系统主要由扫描模块、准光学镜头、校准模块和一维太赫兹探测器阵列组成。成像仪前方人体辐射出的太赫兹波可通过太赫兹窗口进入成像仪，经扫描模块反射后，经准光学透镜聚焦到探测器阵列上。校准模块还设计用于在不干扰成像过程的情况下实时校准太赫兹探测器。结合扫描模块和探测器阵列，成像仪可以以1.5 cm的分辨率和10 fps的帧率获得站在成像仪前方1.5 m处的人体全像。成像系统可以发现人体携带的可疑危险物品，如金属、陶瓷、粉末和液体。此外，基于该系统生成的太赫兹图像，还成功实现了采用卷积神经网络的智能太赫兹成像算法，以提高图像质量并自动标记检测到的物品。我们相信我们的实时视频速率太赫兹成像技术和系统不仅对进一步激发太赫兹成像系统的发展具有重要价值，而且可以加速太赫兹技术走向更实际的应用。5 厘米和 10 fps 的帧速率。成像系统可以发现人体携带的可疑危险物品，如金属、陶瓷、粉末和液体。此外，基于该系统生成的太赫兹图像，还成功实现了采用卷积神经网络的智能太赫兹成像算法，以提高图像质量并自动标记检测到的物品。我们相信我们的实时视频速率太赫兹成像技术和系统不仅对进一步激发太赫兹成像系统的发展具有重要价值，而且可以加速太赫兹技术走向更实际的应用。5 厘米和 10 fps 的帧速率。成像系统可以发现人体携带的可疑危险物品，如金属、陶瓷、粉末和液体。此外，基于该系统生成的太赫兹图像，还成功实现了采用卷积神经网络的智能太赫兹成像算法，以提高图像质量并自动标记检测到的物品。我们相信我们的实时视频速率太赫兹成像技术和系统不仅对进一步激发太赫兹成像系统的发展具有重要价值，而且可以加速太赫兹技术走向更实际的应用。基于该系统生成的太赫兹图像，还成功实现了采用卷积神经网络的智能太赫兹成像算法，提高了图像质量，自动标记了检测到的物品。我们相信我们的实时视频速率太赫兹成像技术和系统不仅对进一步激发太赫兹成像系统的发展具有重要价值，而且可以加速太赫兹技术走向更实际的应用。基于该系统生成的太赫兹图像，还成功实现了采用卷积神经网络的智能太赫兹成像算法，提高了图像质量，自动标记了检测到的物品。我们相信我们的实时视频速率太赫兹成像技术和系统不仅对进一步激发太赫兹成像系统的发展具有重要价值，而且可以加速太赫兹技术走向更实际的应用。