本所声明  |  联系方式  |  中国科学院  |  数字认证(OA)   |  ARP  |  English  |  邮箱

5月10日学术报告

来源: 发布时间:2012-05-10【字体:

报告题目:Femtosecond laser fliamentation science

报告人:陈瑞良教授

单位:Laval University, Canada

报告时间:5月10日下午2:00

报告地点:多功能报告厅

Femtosecond laser filamentation science in air

 

S. L. Chin

Center for Optics, Photonics and Laser (COPL) &

Department of Physics, Engineering Physics and Optics

Laval University

Quebec City, Qc.

Canada

 

Abstract

 

When an intense femtosecond laser pulse propagates in air, it will self-focus resulting in a continuous series of foci, or a filament. Filaments can be formed remotely at different distances with different lengths, in principle. With a Ti-sapphire laser at a wavelength of 800nm (invisible), the color of the pulse will be broadened into the near UV as well as into the infrared after filamentation. This so-called chirped white light laser or supercontinuum could be used as a remote special purpose ‘illuminator’. The intensity inside the filament core being high (5x1013/cm2), nonlinear optical phenomena occur inside the filament. Examples are third and higher harmonics generation, ultrafast birefringence, THz generation, molecular excitation giving rise to fluorescence, population trapping, molecular alignment, etc. Possible applications to remote detection of various chem-bio targets and pollutants as well as the induction of condensation (snow and rain making) will also be discussed.

 

当超强飞秒激光在大气中传输时,自聚焦效应会形成一系列连续的焦点,或者一根光丝。原理上,不同的波长的激光,都可以在远距离产生光丝。对于掺钛蓝宝石激光器输出的800 nm激光而言,其成丝后,脉冲的频率会展宽到近紫外以及远红外的波段,这就是所谓的啁啾白色激光,或者超连续光的产生,它们可以被用来作为一种特殊的照明光源。形成的光丝内部强度很高(5x1013/cm2),诸多非线性光学现象将会在光丝内发生。常见的有三次以及高次谐波的产生,THz辐射、分子激发而带来的荧光强度增益,粒子束缚、分子排列重整等。同时将讨论成丝在对各种生化对象、污染物的遥感探测以及诱导水凝结等方面的应用。

 

欢迎大家参加!

所办公室

2012年5月10号

 


附件下载: