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

Published

January 1, 2008

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

Pub Type

Journals

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 January 15, 2025)