@article{2494, keywords = {pfc}, author = {M. Thorpe and F. Adler and Kevin Cossel and M. de Miranda and Jun Ye}, title = {Tomography of a supersonically cooled molecular jet using cavity-enhanced direct frequency comb spectroscopy}, abstract = {Cavity-enhanced direct frequency comb spectroscopy is used to obtain simultaneously high resolution and broad spectral-bandwidth measurements of a supersonically cooled jet of acetylene molecules. We demonstrate a complete spatial mapping of density, velocity, and internal state distributions of a cold molecular jet via tomographic reconstructions. These measurements reveal interesting and never-before-observed features of the pulsed jet expansion, including anomalous C2H2 absorption lineshapes and anomalous spatial variations of the rotational temperature distribution. The demonstrated capabilities establish this technique as a powerful new tool for studies of cold molecules.}, year = {2009}, journal = {Chemical Physics Letters}, volume = {468}, pages = {1-8}, month = {2009-01}, issn = {00092614}, doi = {10.1016/j.cplett.2008.11.064}, }