ANYL 189 |
| A novel laser-based technique applicable to metastable species detection is discussed. Off-axis integrated-cavity-output spectroscopy (ICOS) has been applied to the detection of singlet (a1Δg) oxygen. Singlet oxygen was generated in a microwave plasma, and the afterglow passed through an off-axis ICOS measurement system consisting of an 82-cm long, high-finesse optical cavity bounded by two highly reflective mirrors. The mirror reflectivity was determined by performing cavity-ringdown measurements and observing ringdown times of 220-250 μs in a range from 1494 nm to 1512 nm. A diode laser was current tuned, and light exiting the cavity was focused onto an InGaAs detector. The cavity transmission was recorded as a function of laser frequency. Details of the method will be presented as well as the spectroscopic characterization of selected transitions of the (1,0) band of the b1Σ -a1Δ Noxon system of oxygen (radiative lifetime 160 minutes) confirming the first observation of this 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 |