Quantum Photonics Lab develops new optic gas sensor with parts per billion sensitivity

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June 18, 2014

High-sensitivity detection of dilute gases is demonstrated by monitoring the resonance of a suspended polymer nanocavity. The inset shows the target gas molecules (darker) interacting with the polymer material (lighter). This interaction causes the nanocavity to swell, resulting in a shift of its resonance. Credit: H. Clevenson/MIT  Read more at: http://phys.org/news/2014-06-optical-sensors-exposed-gas.html#jCpWorking with members of the Quantum Photonics Laboratory (QPL) under the direction of EECS assistant professor Dirk Englund, principal author Hannah Clevenson, EECS graduate student, and Pierre Desjardins and Xuetao Gan have developed an optical gas sensor that provides an extremely sensitive and compact way to detect very small amounts of target molecules of gas before they disperse. Their work titled "High sensitivity gas sensor based on high-Q suspended polymer photonic crystal nanocavity" can be found in the Jun 17, 2014 Applied Physics Letters.

Using microscopic polymer light resonators, fabricated from PMMA, an inexpensive and flexible polymer that swells when it comes into contact with a target gas, the researchers have developed new optical sensors with predicted detection levels in the parts-per-billion range. Optical sensors are ideal for detecting trace gas concentrations due to their high signal-to-noise ratio, compact, lightweight and safe-to-handle nature, and immunity to electromagnetic interference. PMMA can also be treated to interact with a wide range of different target chemicals — permitting a wide range of potential applications from safety applications in industry, environmental and security sensing to medical settings where the polymer can be treated for specific antibodies.  

Read more at: http://phys.org/news/2014-06-optical-sensors-exposed-gas.html#jCp