Cutting-edge elliptically and circularly polarized terahertz technology

太赫兹（THz）部分的电磁波谱，位于电子频率（>.1太赫兹）之上，光子学频率（< 30太赫兹）之下，代表了光的商业应用的最后前沿。这些太赫兹脉冲的大量应用是可能的，其中许多依赖于太赫兹辐射穿过非导电和非极性材料的能力，如衣服，某些食品和普通包装材料。最近，对强太赫兹脉冲的产生和应用的研究激增，这反过来又为创新和科学发现开辟了新的机会。然而，到目前为止，所有的非线性太赫兹实验都是使用线极化的强太赫兹脉冲。******通过该RTI提案支持的研究计划旨在加速使用椭圆和圆极化（ECP）太赫兹脉冲的太赫兹（THz）科学和技术的研究。它将允许申请人和共同申请人建立，保持和加强他们在非线性ECP太赫兹效应研究中的领导地位。我们的目标是产生具有前所未有的峰值场的ECP太赫兹脉冲，并实现具有高信噪比（SNR）的非线性太赫兹测量。反过来，这将导致对T. Ozaki小组最近发现的现象有更全面的理解。该研究计划还将研究允许对太赫兹脉冲的偏振状态进行亚周期控制的新技术，从而为线性和非线性太赫兹光谱引入新的参数。我们还将研究T. Ozaki小组开发的独特的太赫兹偏振探测器，用于改进黑色塑料的分类，从而对加拿大产生重大的社会经济效益。为了实现这些不同的项目，我们需要以下设备：(1)一个高重复率，超高压电源，以增加我们的强太赫兹源的峰值太赫兹场。(2)用于对准和优化强太赫兹源的太赫兹相机。(3)定制太赫兹环面镜，校正像散，紧密聚焦强太赫兹光束，实现前所未有的峰值太赫兹场。**

The terahertz (THz) portion of the electromagnetic spectrum, lying above the frequencies of electronics (>0.1 THz) and below those of photonics (< 30 THz), represents the last frontier of the commercial applications of light. A multitude of applications is possible with these THz pulses, many of which rely on the ability of THz radiation to pass through non-conducting and non-polar materials such as clothing, certain foods and common packing materials. More recently, there has been a significant surge in studies on the generation and application of intense THz pulses, which in turn is opening new opportunities for innovations and scientific discoveries. However, all nonlinear THz experiments up to now have used linearly polarized intense THz pulses.******The research program to be supported through this RTI proposal aims to accelerate the study of terahertz (THz) science and technology that uses elliptically and circularly polarized (ECP) THz pulses. It will allow the applicant and co-applicants to establish, maintain and strengthen their leadership in the study of nonlinear ECP THz effects. We aim to generate ECP THz pulses with unprecedented peak fields and enabling nonlinear THz measurements with a high signal-to-noise ratio (SNR). This, in turn, will lead to a more comprehensive understanding of a phenomenon recently discovered by T. Ozaki's group. The research program will also study new techniques that will allow subcycle control of the polarization state of THz pulses, thereby introducing a new parameter for linear and nonlinear THz spectroscopy. We will also study the unique THz polarization detector developed by T. Ozaki's group for use in improving the sorting of black plastics, thus having significant socio-economic benefits to Canada. To allow these various projects, we are requesting the next equipment: (1) A high-repetition-rate, ultra-high-voltage power supply, to increase the peak THz field of our intense THz source. (2) A THz camera for aligning and optimizing our intense THz source. (3) Custom THz toroidal mirrors to correct for astigmatism and to tightly focus the intense THz beam to achieve unprecedented peak THz fields. **