ANYL 184 |
| We demonstrate a new form of cavity ringdown spectroscopy utilizing a broad bandwidth optical frequency comb coherently coupled to a high finesse optical cavity inside which molecular samples are located. Hundreds of thousands of optical comb components, each coupled into a specific longitudinal cavity mode, undergo ringdown decays when the cavity input is shut off. This provides sensitive intracavity absorption information simultaneously available across 100 nm in the near IR or IR spectral regions. The near IR spectral information is provided using a mode-locked Ti:Sapphire laser that covers 750 to 850 nm while the IR spectra are generated by a mode-locked fiber laser covering 1500 nm to 1600 nm. By placing various atomic and molecular species inside the cavity, we demonstrate real-time, quantitative measurements of the trace presence, transition strengths and linewidths, and population redistributions due to collisions and temperature changes. Results for a variety of molecular species will be presented in both spectral regions as well as a discussion of the future directions of this technique including high resolution “single comb” spectroscopy and the prospects for a robust and inexpensive broadband trace detection system. |
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Has Cavity-Enhanced Detection Come of Age?
8:30 AM-11:30 AM, Monday, 11 September 2006 Moscone Center -- Room 130, Oral
Division of Analytical Chemistry |