理学院"当代科学前沿讲坛"第214讲
                                             物理学科Seminar
报告主题： Femtosecond laser filament based intense THz source: generation, control and application （基于飞秒激光成丝的太赫兹光源：产生、控制与应用）
报告人：王铁军 研究员（中科院上海光机所强场激光物理国家重点实验室)
时间：2015年11月20日（周五)10:00
地点：校本部G309
主办部门：理学院物理系
邀 请 人：金钻明、马国宏教授

报告摘要： Terahertz (THz) wave is an electromagnetic radiation with a general frequency interval from 0.1 to 10 THz. Due to its unique properties, THz science and technology based on table-top laser system is finding use in an increasingly wide variety of important applications: information and communications technology, global environmental monitoring, biology and medical sciences, homeland security, etc.. However, the delivery of energetic THz at a remote position in the atmosphere is, as of now, limited by linear diffraction and the strong attenuation due to water vapor.Broadband and rather powerful THz pulses generated from femtosecond laser filamentation in air would provide a new prospective tool for remote THz nonlinear optics and spectroscopy because the technique allows the generation of intense near single-cycle THz pulses at long distance by controlling the remote onset of the filament via controlling the initial laser parameters.

In this talk, I shallbegin with a brief introduction on femtosecond laser filamentation then briefly review our recent progress on intense, broadband THz generation from femtosecond laser filaments in air. There results include pulse chirp control, molecular alignment control, external DC filed control, external focusing control on the optimization of THz radiation. Towards remote intense THz generation, we shall talk about our work on few μJ THz radiation at a distance of few tens meters away. As for an application, a spatially resolved measurement of plasma density along femtosecond laser filament in air via THz spectroscopywill be also discussed.