Ph.D. Defense: Justin Paul

    Date: 
    Thursday, March 12, 2015 - 9:00am
    Location: 
    Meinel 647
    Description: 

    “Construction and Characterization of a Neutral Mercury Magneto-Optical Trap and Precision Spectroscopy of the 61S0 - 63P0 Mercury-199 Clock Transition”

    Abstract(s): 

    In this dissertation Paul presents theory and experimental results obtained in the Jones research group at the University of Arizona investigating the feasability of neutral mercury as a candidate for an atomic clock. This investigation includes laser cooling and trapping of several neutral mercury isotopes as well as spectroscopy of the 61S0 - 63Pdoubly forbidden clock transition in neutral mercury-199.

    They demonstrate precision spectroscopy of the ground state cooling/trapping transition of neutral mercury at 254 nanometers using an optically pumped semiconductor laser. This demonstration exhibits the utility of optically pumped semiconductor lasers in the eld of precision atomic spectroscopy. The OPSL lases at 1,015 nanometers and is frequency quadrupled to provide the trapping light for the ground state cooling transition. They get up to 1.5 watts single-frequency output power having a linewidth of less than 10 kilohertz in the infrared with active feedback. They frequency-quadruple the OPSL in two external cavity stages to produce up to 120 milliwatts of deep-ultraviolet light at 253.7 nanometers.

    Paul gives a detailed characterization of the construction and implementation of the neutral mercury vapor cell magneto-optical trap. The trap can be loaded in as quickly as 75 milliseconds at background vapor pressures below 108 torr. At reduced background pressure (less than 1,010 torr) the loading time approaches two seconds. They describe construction and stabilization of a laser resonant with the mercury-199 clock transition and the methods employed to perform the experimentally delicate spectroscopy of the clock transition. They present experimental results and analysis for our initial spectroscopy of the 61S0 - 63P0 clock transition in the mercury-199 isotope of neutral mercury.