Traditionally, infrared molecular spectroscopy has been performed with frequency-domain measurement techniques. Recent experiments have exploited the outstanding temporal coherence of state-of-the-art femtosecond lasers to overcome long-standing sensitivity and dynamic range limitations of these traditional techniques, with time-domain measurements of the electric field associated with the light-matter interaction. This talk addresses new developments of coherent infrared technology, affording (i) Watt-scale-average-power coverage of the entire molecular fingerprint region, with a spectral brightness exceeding even that of synchrotrons, (ii) background-free, high-sensitivity and high-dynamic range time-domain detection of molecular vibrations via electro-optical sampling with (iii) attosecond temporal accuracy. These advances herald a new regime for time-, frequency- and space-resolved molecular vibrational metrology.
