Cutting-edge elliptically and circularly polarized terahertz technology

电磁频谱的太赫兹(THz)部分高于电子学的频率(&gt；0.1太赫兹)，低于光子学的频率(&lt；30太赫兹)，代表了光商业应用的最后前沿。利用这些太赫兹脉冲可以实现多种应用，其中许多都依赖于太赫兹辐射穿透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，关于产生和应用强太赫兹脉冲的研究出现了显著的激增，这反过来又为创新和科学发现打开了新的机会。然而，到目前为止，所有的非线性太赫兹实验都使用了线偏振的强太赫兹脉冲。*通过这项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。它将允许申请者和共同申请者建立、保持和加强他们在研究非线性ECP太赫兹效应方面的领导地位。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，这将使人们更全面地理解小崎骏团队最近发现的一种现象。该研究计划还将研究新的技术，允许子周期控制太赫兹脉冲的偏振状态，从而为线性和非线性太赫兹光谱引入一个新的参数。我们还将研究由T.Ozaki的团队开发的独特的THz极化检测器，用于改善黑色塑料的分类，从而为加拿大带来显著的社会经济效益。为了实现这些不同的项目，我们需要下一个设备：(1)一个高重复频率的超高压电源，以增加我们的强THz源的峰值THz场。(2)一台太赫兹相机，用于对准和优化我们的强太赫兹光源。(3)定制的太赫兹环形反射镜，以校正散光和紧密聚焦强度太赫兹光束，以获得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. **