题目:Extreme nonlinear THz Optics

报告人：Professor Tsuneyuki Ozaki

INRS-EMT, 1650 blvd. Lionel-Boulet, Varennes, Québec J3X 1S2, Canada

摘要：

Tabletop sources of high-field terahertz (THz) pulses are currently a hot topic, which is being pursued by many groups around the world. While the favourite method for intense THz generation is optical rectification in nonlinear crystals, research on using other novel methods have shown promising results, including those using air-plasmas, relativistic laser-solid interactions, and large aperture photoconductive antennas. At the Canadian Advanced Laser Light Source, we have built an array of intense THz sources with different central frequencies, with peak THz electric fields ranging from few 100 kV/cm to few MV/cm. In parallel, we have used these sources to study the nonlinear THz response of various materials.

In this talk, I will first quickly review the various components of the “intense THz rainbow” at ALLS. I will then describe more in detail our recent results on intense THz sources based on relativistic laser-solid interactions, and the use of nanorod targets to increase the THz conversion efficiency by 28 times. This provides us with an excellent opportunity for multi-mJ THz sources, which when focused could reach peak intensities of 10¹⁴ Wcm^-2. Finally, I will present our recent results on the nonlinear THz spectroscopy of monolayer graphene. By using gated graphene samples to control their Fermi level energy, we show that their nonlinear response in the THz regime changes drastically when the Fermi level is at or away from the charge neutral point. Comparison with simulations reveals the mechanism involved in such changes.

简介：

Tsuneyuki Ozaki graduated from the University of Tokyo, Tokyo, Japan, in 1987, where he also received his M.Sc. and Ph.D. degrees in 1989 and 1998, respectively. From 1990 to 2000, he was a Research Associate at the Institute for Solid State Physics, University of Tokyo. From 2000 to 2003, he was a Research Specialist at Nippon Telegraph and Telephone (NTT) Basic Research Laboratories, Atsugi, Japan. In 2003, he joined the Institut National de la Recherche Scientifique (INRS), Varennes, QC, Canada, as an Assistant Professor. He is currently a Full Professor, and the former Director of the Advanced Laser Light Source (ALLS) facility. Since 2006, he has also been an InvitedResearcher at the Research Centre Maisonneuve-Rosemont Hospital, Université de Montréal, Montreal, Canada. His main research interests include high-intensity THz radiation sources and their applications, intense high-order harmonic generation, and the use of lasers in biology and medicine. T. Ozaki is currently serving on the Board of Directors of the International Committee on Ultra-high Intensity Lasers (ICUIL), and is the Canadian representative to IUPAP for Commission 17 “Laser Physics and Photonics”.

时间：2016年3月2日上午10：00

地点：中科院物理研究所M236会议室

联系人：金奎娟 研究员 （Tel：82648099）

邀请人：李玉同 研究员 （Tel：82648014）

主办单位：中国科学院光物理重点实验室