High-resolution spectroscopy of 115In+ and prospects for an optical frequency reference

Will Trimble (Final exam)
Department of Physics, University of Washington

The indium ion is among candidates for optical frequency references because of the high quality factor (Q = 1.5 x 10^15) and the small quadrupole and blackbody shifts of its ground-state to 3P0 transition. We report high-resolution spectroscopy of this transition at 237 nm in single indium ions confined in a Paul-Straubel trap using a frequency-quadrupled diode laser to cool the ion on the stronger 1S0-3P1 transition and a frequency-quadrupled Nd:YAG nonplanar ring oscillator (NPRO) at 946 nm stabilized to a vertically-mounted high-finesse optical cavity.