• Tiny lasers enable more-sensitive chemical detection

    April 23, 2008, Cambridge, MA--Federico Capasso and colleagues at Harvard University are developing a new type of infrared spectrometer that uses a tiny array of quantum cascade lasers on a chip instead of thermal sources to generate the infrared rays.
    April 23, 2008
    2 min read

    April 23, 2008, Cambridge, MA--Federico Capasso and colleagues at Harvard University are developing a new type of infrared spectrometer that uses a tiny array of quantum cascade lasers instead of thermal sources to generate the infrared rays.

    A team lead by Capasso, his student Benjamin Lee, and his postdoctoral fellow Mikhail Belkin, has built one of these instruments, which features a chip that is smaller than a dime that holds an array of 32 lasers, each emitting a distinct wavelength and together covering a broad spectral range in the infrared region.

    In a paper to be presented next month at the 2008 Conference on Lasers and Electro-Optics/Quantum Electronics and Laser Science Conference (CLEO/QELS), "Continuously Tunable Compact Single-Mode Quantum Cascade Laser Source for Chemical Sensing," the researchers demonstrate that their device could identify common chemicals as well as a conventional tabletop instrument, which has a much larger footprint. It is the first time that a laser of this type, capable of such performance, has been reported.

    The advantage of using a laser source is that lasers are much brighter than thermal sources thus providing a higher signal-to-noise ratio. The lasers can also be fine-tuned to provide wavelengths on demand to scan accurately for chemicals of interest.

    Sign up for Laser Focus World Newsletters
    Get the latest news and updates.

    Voice Your Opinion!

    To join the conversation, and become an exclusive member of Laser Focus World, create an account today!