Ultrafast Terahertz Polarimetry Enabled by Semiconductor Nanowire Sensors

脉冲太赫兹（THz）辐射已被证明在光谱学、材料表征、安全筛查、通信、质量控制和医学成像等应用中特别强大。相当多的信息被编码在太赫兹脉冲的偏振状态中，然而到目前为止，大多数太赫兹光谱仪和成像系统都没有记录完整的偏振信息。因此，记录和利用极化信息的能力，可以使太赫兹脉冲上编码的信息翻倍，为太赫兹系统的现有应用以及新应用提供了巨大的潜在好处。我们最近开发了一种基于半导体纳米线（NWs）的新技术，有望开辟一个令人兴奋和强大的太赫兹偏振学新领域。该项目将利用我们的发现，利用nw技术创造一个超快太赫兹偏振计，这将牢固地建立这个新领域，并使其进入一系列学科。超快太赫兹偏振计的力量将在两个关键领域得到证明：(i)纳米级和新型薄膜半导体的电子特性的提取，以及（ii）太赫兹超表面的发展和表征。

Pulsed terahertz (THz) radiation has proved particularly powerful in applications such as spectroscopy, materials characterisation, security screening, communications, quality control and medical imaging. Considerable information is encoded in the polarisation state of a THz pulse, yet to date most terahertz spectrometers and imaging systems do not record full polarisation information. Thus, the ability to record and harness polarisation information, which can double the information encoded on a THz pulse, offers huge potential benefits to existing applications of THz systems as well as new applications. We recently developed a new technology based on semiconductor nanowires (NWs) that promises to open up an exciting and powerful new field of terahertz polarimetry. This project will capitalise on our discovery by using the NW-technology to create an ultrafast THz polarimeter, that will firmly establish this new field and make it accessible to a range of disciplines. The power of the ultrafast THz polarimeter will be demonstrated in two key areas: (i) the extraction of the electronic properties of nanoscale and novel thin-film semiconductors and (ii) the development and characterisation of terahertz metasurfaces.