Speaker: Speaker: Lotte Holmegaard (Kemisk Institut, Aarhus Universitet)
Title: Laser-induced alignment and orientation of quantum-state-selected molecules
Time: Today, 15.15 to 16.00
Place: Aud. D1 at the
Math Department
Abstract:
We demonstrate how an inhomogeneous
static electric field can deflect a cold beam of polar molecules. The
deflection spatially disperses the rotational quantum states of the molecules,
enabling quantum-state selectivity. In particular, the ground state experiences
the largest Stark shift and molecules residing in this state are deflected the
most.
The goal of our experiment is to
isolate and use rotational ground-state molecules, or at least samples of
molecules in the lowest-lying rotational states as targets for further
experiments.
So far we have obtained unprecedented
strong degree of alignment (confinement of one or more molecular axes to the
laboratory frame), induced by moderately intense laser pulses, as well as
strong molecular orientation (directional confinement of the permanent
dipole-moment of the molecule) induced by a mixed laser and static field. The prospect of confining an ensemble
of molecules to the laboratory frame opens the door to various experimental
studies from the molecule’s point of view. Especially we are interested in
studying photoelectron angular distributions from aligned or oriented
molecules.
Peter Staanum and
Nicolai Nygaard
Nicolai Nygaard
Institut for Fysik og Astronomi
Aarhus Universitet
Ny Munkegade 120, Bygn. 1520 (kontor 634)
8000 Århus C
Denmark
Telephone: +45 89 42 36 80
Fax: +45 86 12 07 40