15min:
CAVITY-ENHANCED DIRECT FREQUENCY COMB VELOCITY MODULATIO SPECTROSCOPY.

LAURA SINCLAIR, KEVIN COSSEL, WILLIAM AMES, JUN YE AND ERIC CORNELL, JILA, University of Colorado Boulder, and the National Institute for Standards and Technology, Boulder, Colorado 80309..

We have developed a novel technique for broad bandwidth and high resolution survey spectroscopy of molecular ions. Cavity-enhanced direct frequency comb spectroscopy (CE-DFCS) provides broad bandwidth and high resolution by using individual comb lines as parallel detection channels. Here we combine CE-DFCS with velocity modulation spectroscopy to provide ion-specific detection with further enhanced sensitivity. The first application of this technique will map the electronic states of HfF+ and ThF+, which are integral to the JILA electron electric dipole moment experiment.