High-Resolution Spectroscopy of Carbon Monoxide with Frequency Reference Delivered over Fiber Link

Program Description

The mid-infrared photonics is a key region for molecular physics because it corresponds to the frequencies of nuclear vibrations. High-resolution spectroscopy in the 1-10 μm region has never been deeply investigated due to the lack of widely-tunable and robust laser sources. During my PhD we developed a setup for high-resolution spectroscopy that can be applied in the whole 1–10-micron range by combining the power of QCLs and the accuracy of difference frequency generation using the novel OP-GaP crystals. The mid-IR radiation is traced to the primary frequency standard by means of a 650 km optical fiber link. We demonstrate the robustness of the setup by measuring a vibrational transition in a highly-excited metastable state of CO around 6 μm with 11 digits of precision, more than four orders of magnitude better than any previous result. At the end of the talk, a new prospective to have a mK molecular sample, using Stark deceleration technology, will also be introduced.