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 Email: nygaard@phys.au.dk Web: www.phys.au.dk/~nygaard