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High-Precision Pressure Shifting Measurement Technique Using Frequency-Stabilized Cavity Ring-Down Spectroscopy

Published

Author(s)

D J. Robichaud, Joseph T. Hodges, D Lisak, Charles E. Miller, Mitchio Okumura

Abstract

We describe a high-precision method for measuring pressure shifting of absorption lines. The technique involves the acquisition of high-resolution spectra using a cavity ring-down spectrometer whose length is continuously locked to a frequency-stabilized reference laser over a range of sample pressures. We discuss a relatively large correction arising from the pressure-dependenceof dispersion in the cavity modes, and we demonstrate pressure shifting measurements in air for transitions in the O2 A band. Pressure shifts in the range -0.010 cm^(-1) atm^(-1) to $-$0.007 cm^(-1) atm^(-1)$ are reported. We measured relative positions of line centers to within 70 kHz and determined pressure shifting coefficients over a 5 kPa pressure range with relative uncertainties approximately equal to 0.55%, which constitutes a ten-fold improvement over previous measurements.
Citation
Journal of Quantitative Spectroscopy and Radiative Transfer
Volume
109

Keywords

air refractive index, cavity ringdown spectroscopy, O2 A-band, pressure shift

Citation

Robichaud, D. , Hodges, J. , Lisak, D. , Miller, C. and Okumura, M. (2008), High-Precision Pressure Shifting Measurement Technique Using Frequency-Stabilized Cavity Ring-Down Spectroscopy, Journal of Quantitative Spectroscopy and Radiative Transfer (Accessed April 17, 2024)
Created December 31, 2007, Updated October 12, 2021