报告题目

Controlling and measuring molecular dynamics in a strong field

报 告 人

Prof. Jonathan Marangos, 　Blackett Laboratory, Imperial College London, United Kingdom

报告地点

物理楼 中212

报告时间

2012年9月26日，下午3:00 -- 5:00

联 系 人

彭良友（65027）

报告摘要

High harmonic generation (HHG) is a unique method to produce attosecond XUV burst from which encoded attosecond timescale dynamics can be extracted as for instance from molecular systems. We will discuss how we can synthesize the conditions of generation to improve the prospects for generating attosecond bursts and extracting attosecond timescale information from this emission. Further I will report our recent studies of laser induced strong field processes in aligned CO2 where we have sought to identify the recollision contribution to various channels and to unravel the fragmentation mechanism in a strong field.

We will briefly review molecular HHG spectroscopy experiments, highlighting the limitations imposed by the low ionization potential of most molecules and the restriction on the time window of observation imposed by utilising one colour field in the near-IR and HHG resulting only from the short trajectory. One of the first strategies to overcome these limits consist in employing longer wavelength drive lasers. The second strategy relies on synthesising the laser field using multiple-colour fields. We will present recent progress made towards experimental realization of “the perfect wave” scheme for HHG we proposed several years ago. Latest results from collaboration with the group from TUW (Prof. Andrius Baltuska) using three relative phase locked frequencies will be presented. ÷

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[2] Chipperfield et al PRL, 102, 063003 (2009).

[3] Brugnera et al PRL, 107, 153902 (2011).