THz Active Imaging Systems With Real-Time Capabilities
THz Active Imaging Systems With Real-Time Capabilities
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DOI：
10.1109/tthz.2011.2159559
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发表时间：
2011-09-01
影响因子：
3.2
通讯作者：
Roskos, Hartmut G.
中科院分区：
文献类型：
--
作者：
Friederich, Fabian;von Spiegel, Wolff;Roskos, Hartmut G.
本文介绍了五个主动太赫兹成像模式，我们已经开发和研究在过去几年中的目标，以探索其实时成像的潜力的状态的调查。我们首先介绍了一种新的波导为基础的全电子成像系统，其工作频率为812 GHz。它的突出特点是一个32像素的线性探测器阵列外差操作在第八次谐波。该阵列与用于2-6米物距的望远镜光学系统相结合，达到了适合实时成像的数据采集速度。然后描述的第二系统也是全电子扫描器（现在为大约300 GHz），设计用于8 m的物距，其结合了垂直方向上的机械扫描、水平方向上的合成孔径图像生成以及用于深度信息的调频连续波扫描。第三和第四个系统遵循光电方法，依赖于几个到多个像素的并行电光检测。一个成像器是基于脉冲太赫兹OPO和零差检测与CCD相机，其他的连续波电子或飞秒光电太赫兹源和光子混合器件（PMD）相机。文章最后描述了基于CMOS场效应晶体管的焦平面阵列成像技术的现状。
This paper presents a survey of the status of five active THz imaging modalities which we have developed and investigated during the last few years with the goal to explore their potential for real-time imaging. We start out by introducing a novel waveguide-based all-electronic imaging system which operates at 812 GHz. Its salient feature is a 32-pixel linear detector array heterodyne-operated at the eighth subharmonic. This array in combination with a telescope optics for object distances of 2-6 m reaches a data acquisition speed suited for real-time imaging. The second system described then is again an all-electronic scanner (now for around 300 GHz), designed for object distances of 8 m, which combines mechanical scanning in vertical direction, synthetic-aperture image generation in horizontal direction, and frequency-modulated continuous-wave sweeping for the depth information. The third and fourth systems follow an optoelectronic approach by relying on several-to multi-pixel parallel electrooptic detection. One imager is based on a pulsed THz-OPO and homodyne detection with a CCD camera, the other on either continuous-wave electronic or femtosecond optoelectronic THz sources and a photonic-mixing device (PMD) camera. The article concludes with a description of the state of the art of imaging with focal-plane arrays based on CMOS field-effect transistors.