Grant: Research Tools and Instruments

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. **