DM: Damien: OPA/OPCPA in crystals and fibres

I will do a general discussion/presentation about OPA/OPCPA in non linear crystal and in fiber. I will show some experimental results related to what I did in the PETAL Petawatt project.
material...

DM: Jon: Programme Grant overview & introduction

we plan to extend attosecond science to larger molecules and condensed phase systems building upon our present activity in HHG spectroscopy and attosecond pulse generation. I hope to give a short briefing on the scientific plans
material...

JC: Misha: Radiation Generated by the Ultrafast Migration of a Positive Charge Following the Ionization of a Molecular System

Electronic many-body effects alone can be the driving force for an ultrafast migration of a positive charge created upon ionization of molecular systems. Here we show that this purely electronic phenomenon generates a characteristic IR radiation. The situation when the initial ionic wave packet is produced by a sudden removal of an electron is also studied. It is shown that in this case a much stronger UV emission is generated. This emission appears as an ultrafast response of the remaining electrons to the perturbation caused by the sudden ionization and as such is a universal phenomenon to be expected in every multielectron system.
http://prl.aps.org/abstract/PRL/v106/i5/e053001
What I want everyone to think about is:
- What is the role of the detached electron that they have completely neglected?
- Can this radiation be observed, and if yes, will it be coherent?
PPT slides to follow...#

DM: Luis: how to grow micro and nanostructures, with both, nanosecond and femtosecond laser pulses

(i) Laser irradiation of materials with laser pulses whose energy density is around the ablation limit, no matter whether they are femtosecond or nanosecond pulses, do produce microconical structures despite of the, most likely, different mechanisms involved. These structucture do have several interesting applications.
(ii) We will show how a metalic thin film of nanoparticles can be rearranged just by shining few laser pulses with a well defined intensity structure.
PPT slides to follow...

DM: Malte: Molecular structure dependence of recollision induced fragmentation in N2

After converting the VMI in the Red Dragon lab to an ion time-of-flight spectrometer, it is currently used to investigate those inelastic electron recollisions, which lead to fragmentation. Inelastic recollisions lead to electron-electron interactions in the outer shell of the molecule and investigating them is one of the objectives of attosecond science.
In the lab, we are trying to find out if the recollision induced fragmentation of N2 depends on the alignment of the molecule, or in other words if fragmentation is more probable if the electron hits the molecule parallel or perpendicular with respect to the bond.
I will give a detailed description of the required experimental steps to find an answer to that question and present a few intermediate results. I will try to raise a few questions about the setup and future plans to get input from the group.
Most of the experimental issues are mentioned in the following paper, written by a very familiar Irish man: http://pra.aps.org/abstract/PRA/v73/i4/e043401 Nevertheless, I will briefly discuss them during the meeting as well.
PPT slides to follow...

JC&DM: Tobi: Characterization of high intensity sub-4-fs laser pulses using spatially encoded spectral shearing interferometry

I'll try to give a mini-intro about ultrafast pulse characterisation and the SPIDER technique and discuss the latest attolab output

JC: Will: Higher-Order Kerr Terms Allow Ionization-Free Filamentation in Gases v2.0

follow up on the last Journal Club... http://www.opticsinfobase.org/abstract.cfm?URI=oe-17-16-13429
and http://www.opticsinfobase.org/abstract.cfm?URI=oe-18-3-3011
and: http://pre.aps.org/abstract/PRE/v74/i3/e036406

PDFs for the papers... PPT slides to follow...