Accession Number : ADA621947


Title :   Laser Cooling and Slowing of a Diatomic Molecule


Descriptive Note : Doctoral thesis


Corporate Author : YALE UNIV NEW HAVEN CT


Personal Author(s) : Barry, John F


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a621947.pdf


Report Date : Dec 2013


Pagination or Media Count : 307


Abstract : Laser cooling and trapping are central to modern atomic physics. It has been roughly three decades since laser cooling techniques produced ultracold atoms, leading to rapid advances in a vast array of fields and a number of Nobel prizes. Prior to the work presented in this thesis, laser cooling had not yet been extended to molecules because of their complex internal structure. However, this complexity makes molecules potentially useful for a wide range of applications. The first direct laser cooling of a molecule and further results we present here provide a new route to ultracold temperatures for molecules. In particular, these methods bridge the gap between ultracold temperatures and the approximately 1 kelvin temperatures attainable with directly cooled molecules (e.g. with cryogenic buffer gas cooling or decelerated supersonic beams). Using the carefully chosen molecule strontium monofluoride (SrF), decays to unwanted vibrational states are suppressed. Driving a transition with rotational quantum number R=1 to an excited state with R0=0 eliminates decays to unwanted rotational states. The dark ground-state Zeeman sublevels present in this specific scheme are remixed via a static magnetic field. Using three lasers for this scheme, a given molecule should undergo an average of approximately 100, 000 photon absorption/emission cycles before being lost via unwanted decays. This number of cycles should be sufficient to load a magneto-optical trap (MOT) of molecules. In this thesis, we demonstrate transverse cooling of an SrF beam, in both Doppler and a Sisyphus-type cooling regimes. We also realize longitudinal slowing of an SrF beam. Finally, we detail current progress towards trapping SrF in a MOT. Ultimately, this technique should enable the production of large samples of molecules at ultracold temperatures for molecules chemically distinct from competing methods.


Descriptors :   *DIATOMIC MOLECULES , *MAGNETOOPTICS , *TRAPPING(CHARGED PARTICLES) , ALKALI METAL COMPOUNDS , ANGULAR MOMENTUM , COLD GASES , COOLING , COUPLING(INTERACTION) , CRYOGENICS , DARKNESS , DIPOLE MOMENTS , ELECTRIC MOMENTS , LASERS , MAGNETIC FIELDS , MOLECULAR DYNAMICS , MOLECULAR VIBRATION , NUCLEAR PHYSICS , OPTICAL PROPERTIES , PARTICLE COLLISIONS , PHOTONS , RADIATION PRESSURE , SPIN STATES , STRONTIUM , SUPERSONIC CHARACTERISTICS , TEMPERATURE , THESES , TRANSITIONS , TRANSVERSE , VIBRATION


Subject Categories : Electricity and Magnetism
      Fiber Optics and Integrated Optics
      Nuclear Physics & Elementary Particle Physics


Distribution Statement : APPROVED FOR PUBLIC RELEASE