In recent years, there has been growing interest in methods for producing gases of ultracold polar molecules, driven by proposals to employ ultracold molecules in applications in ultracold chemistry, quantum information and quantum simulation, and precision measurement. Development of direct laser cooling and trapping techniques for molecules has become a particular focus of experimental and theoretical effort, given the success of analogous techniques in producing ultracold atoms and the potential of these techniques to produce ultracold molecules with a variety of structures suitable for use in distinct applications.
Here, we review recent advances in the laser cooling and trapping of strontium monofluoride (SrF). We describe methods for increasing the number of molecules available for trapping via modifications to the scheme for producing and slowing molecules from the molecular beam source. We detail changes to the magneto-optical trapping scheme that allow access to trapped samples at higher densities or lower temperatures. We implement and characterize a sub-Doppler optical molasses stage that efficiently cools SrF molecules to substantially lower temperatures than previously realized. We then describe loading of SrF molecules into a conservative magnetic trap, at temperatures comparable to those commonly used as a starting point in atomic sympathetic and evaporative cooling experiments. Finally, we describe ongoing work towards further laser cooling of SrF and towards observing ultracold atom-molecule collisions in a magnetic trap, an important step in extending sympathetic cooling techniques to ultracold polar molecules.
Thesis Advisor: David DeMille