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In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript. An Author Correction to this article was published on 29 November For trace gas sensing and precision spectroscopy, optical cavities incorporating low-loss mirrors are indispensable for path length and optical intensity enhancement. Optical interference coatings in the visible and near-infrared NIR spectral regions have achieved total optical losses below 2 parts per million ppm , enabling a cavity finesse in excess of 1 million.
However, such advancements have been lacking in the mid-infrared MIR , despite substantial scientific interest. Here, we demonstrate a significant breakthrough in high-performance MIR mirrors, reporting substrate-transferred single-crystal interference coatings capable of cavity finesse values from to near 4.
In a first proof-of-concept demonstration, we achieve the lowest noise-equivalent absorption in a linear cavity ring-down spectrometer normalized by cavity length. This substantial improvement in performance will unlock a rich variety of MIR applications for atmospheric transport and environmental sciences, detection of fugitive emissions, process gas monitoring, breath-gas analysis, and verification of biogenic fuels and plastics.
High-performance resonators integrating low-optical-loss mirrors are used in a wide variety of applications, ranging from time-and-frequency metrology, quantum electrodynamics and optomechanics, to trace gas sensing and detection. Rempe et al. In the MIR, only modest coating advancements have been realized and this technology significantly lags what is readily achievable in the NIR.
