https://www.selleckchem.com/pr....oducts/Floxuridine.h
Optical frequency combs (OFCs) based on quantum cascade lasers (QCLs) have transformed mid-infrared spectroscopy. However, QCL-OFCs have not yet been exploited to provide a broadband absolute frequency reference. We demonstrate this possibility by performing comb-calibrated spectroscopy at 7.7 µm (1305 cm-1) using a QCL-OFC referenced to a molecular transition. We obtain 1.5·10-10 relative frequency stability (100-s integration time) and 3·10-9 relative frequency accuracy, comparable with state-of-the-art solutions relying on nonlin