Supported projects

For the past decade, optical molecular absorption instruments have been used to measure gases (traces, isotopes). The democratization of these instruments in the 2010s has enabled us to increase the number of water isotope analyses in the liquid and vapour phases, and to develop real-time environmental monitoring of pollutant or greenhouse gas concentrations in observatories. Today, laser instruments are seeking to become multi-tracer and competitive on new-generation tracers (isotopic anomalies: Δ¹⁷O, Δ₄₇ and Δ₄₈). Non-destructive multi-tracer measurement (the laser does not alter the gas during measurement) is an advantage for analyses of heritage samples, since parsimony of sampling is essential for their preservation, and the gas thus remains available for other types of analysis. LSCE and its partners have therefore chosen to become autonomous in the design, manufacture and deployment of this new generation of laser machines, based on techniques derived from the world of optical clocks and ultra-stable lasers for measuring water and carbon dioxide. To further develop these instruments, it was necessary to install a frequency comb, a tool that has become the standard in laser frequency measurement. The comb acts as a “ruler”, enabling us to compare the frequency of our lasers, the X axis of the spectra, with the ultra-stable frequency of the comb’s teeth. Coupled with spectroscopic techniques guaranteeing absolute measurement of absorption (CRDS), our Y axis, we then have ultra-precise, fully referenced measurements. The comb is a key module in our infrastructure structured around REFIMEVE, which is currently being developed to provide a unique tool on an international scale for the entire LSCE-GEOPS Panoply regional analytical platform. We are also capitalizing on the fact that the Île-de-France region boasts a highly-developed ecosystem of optical schools, laboratories and industrialists to support us.