Saturated Ultra-Precision Spectroscopy of Water and HD with NICE-OHMS

This research focused on conducting high-resolution spectroscopy on water and deuteride hydrogen molecules, with a particular emphasis on measuring various isotopologues. The investigation showcased the ability to achieve a significant number of measurements with exceptional precision in a short timeframe. For water isotopologues, over 500 transitions were measured with unprecedented uncertainty, highlighting the efficiency of the research approach.
The use of the NICE-OHMS apparatus proved instrumental in demonstrating its sensitivity for trace gas detection. The study successfully saturated many weak lines for the first time, including the dipole allowed rovibrational lines in HD, establishing the apparatus as one of the most sensitive setups available.
In the case of water, the research bridged the gap between ortho and para universes through intricate network schemes, significantly improving the accuracy of over 100 ortho levels by more than two orders of magnitude. This breakthrough offers a potential enhancement in the understanding of water molecules.
In the case of deuteride hydrogen, the research achieved high detection sensitivity, enabling the measurement of rovibrational lines for the first time. Discrepancies with existing calculations were identified, indicating the need for further refinement. Moreover, the study unveiled new effects resulting from strong standing waves, adding novel insights to the understanding of molecular behavior.