David Glenn Abstract

"Towards laser cooling of molecules from a buffer-gas cooled beam source."

ABSTRACT:

We report on the continuing development of a cryogenic buffer-gas cooled molecular beam source. We have characterized the properties of this source for several molecular species and in a variety of buffer-gas flow regimes, ranging from the effusive (thermal mean velocity, moderate flux) to the deeply hydrodynamic (large forward velocity, high flux, high collimation). In particular, we will describe recent work towards demonstrating direct laser cooling of a hydrodynamic SrF molecular beam. We have identified a set of quasi-closed transitions which should enable more than 10^4 photon scattering events, sufficient to decelerate a hydrodynamic beam to the Doppler limit. We present experimental results demonstrating optical deflection of a SrF beam by radiative force using this scheme, in which each molecule scatters in excess of 100 photons, limited by its interaction time with the lasers. Finally, we describe efforts towards confining molecules from this beam source in a microwave-frequency quasi-optical dipole trap.