Scientists have developed a laser-based method that can accurately identify chemicals such as explosives and dangerous gases, an advance that can be used in airport security and monitoring environmental pollutants.
Researchers from University of Michigan in the U.S. used a method called multi-dimensional coherent spectroscopy that uses ultrashort laser pulses to read types of gases like a bar code.
To speed up the process while preserving its accuracy, researchers combined MDCS with another method called dual-comb spectroscopy. Frequency combs are laser sources that generate spectra consisting of equally spaced sharp lines that are used as rulers to measure the spectral features of atoms and molecules with precision.