Characterizing the complete thermodynamic state of a gas using a frequency comb spectrometer

Simple item page
dc.contributor.authorAnonymous,
dc.date.issued2025
dc.description.abstractWe present a metrological technique to characterize the thermodynamic state (temperature, pressure, and density) of gaseous molecules in a single spectroscopic measurement. We demonstrate the accuracy and precision of our approach by using a low-pressure (number density approximately 1.76 × 10¹⁸ molecules/cm³) acetylene gas in a sealed glass cell over a temperature range of −70 °C up to +60 °C. Under these experimental conditions the sample is in the gaseous state, displaying a behavior very close to that of an ideal gas. This allows us to predict the thermodynamic state with high accuracy, and thus rigorously test the performance of our approach. Our spectroscopic measurement uses a tunable wide-band optical frequency comb to acquire the full ro-vibrationally broadened acetylene spectrum between 1512 and 1538 nm with approximately 80-kHz spectral resolution. Through nonlinear fitting of this entire spectrum we obtain high accuracy (<1%) and high-precision (approximately 0.1%) estimates of the temperature, pressure, and density of the gas across the full examined temperature range. This combination of broadband probing and ultra-high-resolution spectrum ensures that we obtain reliable and precise measurements on the thermodynamic state.
dc.description.statementofresponsibilityFaisal Karim, Joshua A. Whitaker-Lockwood, Sarah K. Scholten, Christopher Perrella, and Andre N. Luiten
dc.identifier.citationPhysical Review Applied, 2025; 24(1):014037-1-014037-11
dc.identifier.doi10.1103/vbfp-2yvt
dc.identifier.issn2331-7019
dc.identifier.issn2331-7019
dc.identifier.urihttps://hdl.handle.net/2440/147778
dc.language.isoen
dc.publisherAmerican Physical Society
dc.relation.granthttp://purl.org/au-research/grants/arc/LP120200605
dc.relation.granthttp://purl.org/au-research/grants/arc/LP140100647
dc.relation.granthttp://purl.org/au-research/grants/arc/IC150100019
dc.relation.granthttp://purl.org/au-research/grants/arc/CE230100006
dc.rights© 2025 American Physical Society
dc.source.urihttps://doi.org/10.1103/vbfp-2yvt
dc.subjectAnalytical chemistry; Atomic & molecular collisions; Frequency combs & self-phase locking; Metrology; Molecular spectra; Molecules; Infrared spectroscopy; Optical absorption spectroscopy
dc.titleCharacterizing the complete thermodynamic state of a gas using a frequency comb spectrometer
dc.typeJournal article
pubs.publication-statusPublished online

Files

Collections

Research Outputs