Home Search Infrared Lasers Read Vibrations Of Molecular Bonds Taking a page from modern astronomy, where scientists are making a raft of new discoveries by sampling starlight across the electromagnetic spectrum, a group of chemists from the University of Wisconsin-Madison has refined a powerful new way to probe the molecular universe using infrared light. Building on a technique known as infrared spectroscopy, the Wisconsin chemists use two infrared lasers, choreographed to focus on a small sample, to read the barely detectable but telltale vibrations of molecules that can provide access to previously hidden but critically important information. The new technique, to be reported in the Feb. 14 issue of the scientific journal Physical Review Letters , allows chemists to read the fine print of the molecular world, the connections and fleeting interactions within and between molecules. Such a perspective, according to UW-Madison chemist John C. Wright, could lead to leaps in our understanding of a host of scientific problems, from how some bacteria thwart antibiotics to the weathering of soil.
Molecules are groups of two or more atoms connected by bonds that act like springs.
Through infrared spectroscopy, scientists can read the vibrations, which act like fingerprints to identify a molecule. Taking the technique an important step further, the Wisconsin team has developed a way to use two infrared lasers to pluck two different springlike bonds to get a picture of how all the different bonds in the molecule are connected. Four Wave Mixing. Like NMR, the method developed by Wright and Zhao tunes in to the frequencies at which molecules vibrate. But instead of the radio waves used in NMR, DOVE depends on the concentrated light pulses of lasers to stimulate molecules and provide a window to molecular connections.