Active terahertz two-wire waveguides (phase I)

本提案涉及基于最近实现的有源双线波导的新型紧凑便携式太赫兹时域光谱（THz-TDS）系统的商业原型的开发和演示。我们的发明，被称为太赫兹双线发射机（太赫兹- twt），是由该提案的PI（教授Morandotti）和他的团队开发的。由于这项技术，可以直接在导向结构内产生太赫兹辐射，从而使我们能够克服与低耦合效率和模式不匹配相关的重大问题。由砷化镓片的实施例（扮演太赫兹发射器的角色）在两根金属线之间制作的有源双线波导的演示，在所提出的装置的基础上，导致直接在引导结构内产生太赫兹电场。通过比较有源结构的耦合效率与标准情况下的耦合效率，其中辐射是在波导外产生的，我们报告了相同初始条件下高63倍的能量吞吐量。紧凑型太赫兹- tds将由光纤飞秒激光器直接连接到我们的有源波导、延迟线和样品支架组成。通过在波导末端引入喇叭状锥形，可以显著改善有源波导的外耦合。这种有源波导的几何结构将有利于样品的辐照和太赫兹辐射进入探测器的反向耦合。因此，我们提出的系统将克服通常与标准太赫兹- tds系统相关的限制，通过使用提出的有源波导进行波束转向和引导，以一种新颖且可扩展的配置。反过来，这将大大减少系统的总尺寸，通过削减支持光学器件，同时增加其便携性和紧凑性。该项目的主要目标是推动我们的发明发展，以增加我们知识产权的价值，并扩大可能对我们的技术感兴趣的潜在客户数量，包括新一代超紧凑型太赫兹- tds系统。

The present proposal deals with the development and demonstration of commercial prototypes for a new class of compact and portable Terahertz-Time Domain Spectroscopy (THz-TDS) systems, based on the recent realization of active two-wire waveguides. Our invention, called THz Two-Wire Transmitter (THz-TWT), has been developed by the PI of this proposal (Professor Morandotti) and his team. Thanks to this technology, it is possible to generate THz radiation directly within the guiding structure, thus allowing us to overcome the significant problems associated with a poor coupling efficiency and mode mismatch. The demonstration of an active two-wire waveguide made by the embodiment of a gallium arsenide piece (playing the role of the THz emitter) between the two metallic wires at the basis of the proposed device results in the generation of a THz electric field directly within the guiding structure. By comparing the coupling efficiency of the active configuration with that of the standard case, in which the radiation is generated outside the waveguide, we reported a 63 times higher energy throughput for the same initial conditions. Compact THz-TDS will then consist of a fiber based femtosecond laser directly connected to our active waveguides, a delay line and a sample holder. Out-coupling from the active waveguides can be significantly improved by introducing horn-shaped tapers at the end of the waveguide. Such geometry for the active waveguide will facilitate the irradiation of the sample and the back-coupling of THz radiation into the detector. Our proposed system will thus overcome the limitations, typically associated to standard THz-TDS systems, by using the proposed active waveguides for beam steering and guiding, in a novel and scalable configuration. In turn, this will significantly reduce the total size of the system by cutting the supporting optics while increasing its portability and compactness. The main objective of the proposed project is to push forward the development of our invention with the aim to increase the value of our intellectual property and to enlarge the number of potential customers who might be interested in our technology, consisting of a new generation of ultra-compact THz-TDS systems.