PHotonIc THz Synthesis for Imaging and detectioN (PHITSIN)

对随身携带爆炸物的检测是当前一个重要的安全问题。炸药以一种特有的方式吸收高频波，这取决于这些波的频率。我们感兴趣的频率在太赫兹（THz）范围内，大约是移动电话使用频率范围的1000倍。这些频率的信号可以穿过衣服，几乎没有被吸收，因此可以探测到隐藏的爆炸物。产生如此高频率的信号是困难的，通常需要一个巨大而昂贵的激光器，其功耗与电烤箱相似。这种系统在检查人们是否携带爆炸物方面不太实用。我们已经开发出非常有效的光到太赫兹信号的转换器，可以与非常小的半导体激光器一起使用，需要大约1瓦的总功率，大约与一个小火炬相同。在这个项目中，我们建议使用这些转换器与一个新的和非常敏感的探测方案来创建一个探测隐藏爆炸物的系统。此外，这种技术可用于小型扫描系统，以查明隐藏的武器和其他有关安全的项目。

The detection of explosives carried about the person is an important current security concern. Explosives absorb high frequency waves in a characteristic manner, depending on the frequency of those waves. The frequencies of interest are in the teraHertz (THz) range, about a thousand times as high as the frequency range used by mobile phones. Signals at these frequencies can pass through clothes with little absorption, so that concealed explosives can be detected.Generating signals at such extremely high frequencies is difficult and usually requires a large and expensive laser having power consumption similar to an electric oven. Such a system is not very practical for checking whether people are carrying explosives.We have developed very efficient converters of light to THz signals which can be used with very small semiconductor lasers, requiring a total power of about 1 W, about the same as a small torch. In this project we propose to use these converters with a new and very sensitive detection scheme to create a system for detecting concealed explosives.In addition this type of technology could be used in a compact scanning system to identify concealed weapons and other items of security interest.