| Author(s): |
D J. Robichaud; Joseph T. Hodges; D Lisak; Charles E. Miller; Mitchio Okumura; |
| Title: |
High-Precision Pressure Shifting Measurement Technique Using Frequency-Stabilized Cavity Ring-Down Spectroscopy |
| Published: |
January 01, 0008 |
| 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 |
| Pages: |
pp. 435 - 444 |
| Keywords: |
air refractive index;cavity ringdown spectroscopy;O2 A-band;pressure shift |
| Research Areas: |
Remote Sensing, Spectroscopy, Electronic, Near Infra-Red |
