Sensitivity enhancement in off-axis integrated cavity output spectroscopy.
We report on a detailed model of an improved three mirror off-axis integrated cavity output spectroscopy (OA-ICOS) setup, which re-injects the light reflected by the optical cavity. The model simulates the impact of design parameters on instrument sensitivity and can be used for any off-axis configuration. We demonstrate the application of this model for the real-time detection of ethylene with a pulsed quantum cascade laser (QCL). The three mirror OA-ICOS scheme provides a 10 times increase in signal-to-noise ratio as compared to standard OA-ICOS, resulting in a noise equivalent absorption sensitivity of 1.5 x 10(-8) cm(-1) Hz(-1/2).
R
R
Centeno
J
J
Mandon
S M
SM
Cristescu
F J M
FJ
Harren
D004867:Equipment Design; D054023:Lasers, Semiconductor; D008027:Light; D009569:Nitric Oxide / Q000032:analysis*; D015203:Reproducibility of Results; D059629:Signal-To-Noise Ratio; D013057:Spectrum Analysis / Q000295:instrumentation*
D009569:Nitric Oxide