Broadband Comb-over

To record a useful spectrum in a reasonable time, the spectroscopist must juggle bandwidth, resolution, sensitivity, and acquisition times.

In a technique such as cavity-ringdown spectroscopy (CRDS), high detection limits are possible but this is offset by a narrowing of the range of frequencies that can be followed quickly. However, US researchers have now developed a broadband version of this technique that neatly combs over the issue of frequency limitations and can now achieve high sensitivity, broad spectral bandwidth, high resolution, and fast acquisition times simultaneously. The team reports in the journal Science a proof of principle experiment in recording CRDS spectra from the visible to near-infrared for species such as acetylene, dioxygen, water, ammonia and argon.

You can read about this latest research in the first April issue of SpectroscopyNOW. You can find more of my news reports for the spectroscopy site here.