Monolithic Resonant TeraHertz Detectors

可见光只是整个电磁波谱中很小的一部分。无线电频谱对大多数人来说也很熟悉，但不太为人所知的是两者之间的波长范围。在这个项目中，我们对频谱的一部分特别感兴趣，它被称为太赫兹波段，之所以这样称呼是因为频率在1thz左右。太赫兹波段的光可以穿过可见光不透明的材料，但是，波长仍然足够小，可以分辨小于1毫米的特征。正因为如此，太赫兹吸引了很多应用的兴趣，在这些应用中，我们需要透过材料看到东西，同时也能拍出清晰的照片。应用包括医疗和安全成像，特别是因为太赫兹是非电离的，所以可以安全地用于人类。不幸的是，太赫兹技术面临着一些需要研究才能克服的重大困难。明亮的太赫兹光源很难制造，因此需要付出相当大的努力来改进我们目前拥有的光源。太赫兹在能量上与环境辐射热相似，因此传感器必须既灵敏又具有高度的分辨能力。在一个完整的太赫兹成像系统中，技术及其组件的各个方面都是决定整体性能的重要因素。因此，该项目致力于提高传感器的性能。我们想要一个好的传感器有很多属性。它应该体积小，耗电少，灵敏度高，理想情况下，如果要用于相机，速度要足够快，可以进行视频速率成像。我们建议利用半导体材料的光学特性和精心设计的金属结构来捕获太赫兹辐射。我们将演示这些结构可以用来制作传感器阵列，就像你在普通相机中发现的那样，并且传感器对太赫兹是敏感和选择性的。就像主流摄影得益于微电子技术使数码相机成为可能一样，我们也将能够利用集成电路技术使许多传感器可以廉价而高效地放在单个芯片上。我们的项目吸引了包括Teraview和Selex-Galileo在内的英国领先公司的支持，这些公司可以立即将成功的技术推向市场。我们的目标是完成将展示新技术的研究，进一步的投资将使科学家、临床医生和安全部门能够在不久的将来使用新产品。

Visible light is only a very small part of the whole electromagnetic spectrum. The radio spectrum is also very familiar to most people, but less well known is the range of wavelengths in between. In this project we are particularly interested in a part of the spectrum that has come to be known as the terahertz band, so called because the frequency is around 1 THz. Light in the terahertz band can pass through materials that are opaque to visible light, but yet, the wavelength is still small enough to resolve features smaller than 1 mm. Because of this terahertz has attracted a great deal of interest for applications where we need to see through materials, but also take good sharp pictures. Applications include medical and security imaging, particularly because terahertz is non-ionising so can be safely used with humans.Unfortunately terahertz technology suffers from some significant difficulties that requires research to overcome. Bright terahertz sources are difficult to make, so considerable effort is needed to improve what we have at the moment. Terahertz is energetically similar to ambient radiated heat, so sensors have to be both sensitive and highly descriminating. In a complete terhertz imaging system all aspects of the technology and its components are important in determining the overall performance. This project is therefore dedicated to improving sensor performance.There are a number of attributes that we would like for a good sensor. It should be small, consume little power, be very sensitive, and ideally, if it it to be used in an camera, fast enough to allow video rate imaging. We propose to use the optical properties of semiconducting materials and carefully designed metallic structures to capture terahertz radiation. We will demonstrate that these structures can be used to make an array of sensors, just as you would find in a normal camera, and that the sensors are sensitive and selective to terahertz. In the same way that mainstream photography has benefited from microelectronics to make digital cameras possible, we will also be able to make use of integrated circuit technology so that many sensors can be cheaply and efficiently put on to a single chip.Our project has attracted support from leading UK companies including Teraview and Selex-Galileo that have immediate routes to market for successful technology. Our aim is to complete the research that will demonstrate new technologies to the point where further investment will enable the creation of new products that can be used by scientists, clinicians and the security services in the not to distant future.