Sensing and Analysis of THz-Radiation using the Coherence Function (SensATion)

使用相干函数 (SensATion) 感测和分析太赫兹辐射

• 批准号: 423266368
• 负责人: Professor Dr. Ralf Bernhard Bergmann
• 金额: --
• 依托单位: BIAS - Bremer Institut für Angewandte Strahltechnik GmbH
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/423266368?language=en
• 关键词: Sensing; Analysis; THz; Radiation; using

In the spectrum of electro-magnetic waves, Terahertz (THz) radiation is located between microwaves and the infrared spectrum with frequencies ranging from 100 GHz up to multiple THz and offers a number of significant advantages compared to other spectral regimes. While being non-ionizing, it can penetrate materials which are opaque to visible light. Additionally, the frequencies are in the range of molecular vibration, rotation and transition spectra, making it well suited to detect and identify chemicals and materials such as drugs and explosives for example. In the past decades various methods for coherent imaging in the THz range have been reported. They allow to exploite the wave nature of the radiation and therefore enable advanced applications, such as quantitative phase contrast imaging, digital holography, and ultra-fast spectroscopy.However, currently all of the available coherent imaging techniques in the THz range are based either on a superposed reference wave field, or a reference pulse for electronic gating. This constitutes a considerable lack in the state of the art, because in consequence there are currently no means to characterize a priori unknown THz radiation, e.g. emitted by antennas, non-linear photonic components, potentially self-luminous or stellar objects in a far distance or non-classical radiation in quantum optics.The goal of this project is to close the gap in the state of the art and to research and develop methods in order to provide reference free wave field sensing in the THz range. The approach shall be based on sampling of the mutual coherence function (i.e. the spatial coherence) using a shear interferometer. If successful, this would for the first time allow recording and analysis of a priori unknown THz radiation even in case of partial spatial coherence. Applications would range from characterization of photonic components, antennas, self-luminous and distant objects as well as investigations in quantum optics. Furthermore, currently existing applications in coherent imaging would largely benefit from a reference free technique. Avoiding the burden of guiding and controlling a reference wave enables novel flexible and compact coherent imaging sensors that can be moved around like a camera device.

在电磁波频谱中，太赫兹 (THz) 辐射位于微波和红外频谱之间，频率范围从 100 GHz 到多个 THz，与其他频谱体系相比，它具有许多显着的优势。虽然是非电离的，但它可以穿透对可见光不透明的材料。此外，频率处于分子振动、旋转和跃迁光谱范围内，使其非常适合检测和识别化学品和材料，例如毒品和爆炸物。在过去的几十年中，已经报道了太赫兹范围内的相干成像的各种方法。它们可以利用辐射的波性质，从而实现先进的应用，例如定量相衬成像、数字全息术和超快光谱。然而，目前太赫兹范围内所有可用的相干成像技术都基于叠加的参考波场，或电子选通的参考脉冲。这构成了现有技术的相当大的缺陷，因为目前还没有手段来表征先验未知的太赫兹辐射，例如太赫兹辐射。由天线、非线性光子元件、远距离潜在自发光或恒星物体或量子光学中的非经典辐射发射的光。该项目的目标是缩小现有技术的差距，并研究和开发方法以便在太赫兹范围内提供参考自由波场感测。该方法应基于使用剪切干涉仪对相互相干函数（即空间相干性）进行采样。如果成功，这将首次允许记录和分析先验未知的太赫兹辐射，即使在部分空间相干的情况下也是如此。应用范围包括光子元件、天线、自发光和远距离物体的表征以及量子光学的研究。此外，当前相干成像中现有的应用将很大程度上受益于无参考技术。避免引导和控制参考波的负担使得新型灵活且紧凑的相干成像传感器可以像相机设备一样移动。