Researchers at the National Institute of Standards and Technology (NIST) have developed a groundbreaking laser-based technique called “free-form dual-comb spectroscopy” that could drastically improve our ability to analyze and detect greenhouse gases like methane. This innovative technology offers faster, more sensitive, and flexible ways to identify and monitor various materials, potentially aiding in the fight against climate change.
Harnessing the Power of Dual-Comb Spectroscopy
Central to the new technology is a Nobel Prize-winning laser tool, the optical frequency comb, which emits light at discrete and precisely spaced frequencies. The “dual-comb” part comes from using two of these fancy-schmancy frequency combs at once to very quickly and finely measure substances by looking at how they modulate the light coming from each comb.
The method is considerably faster than single-comb methods while offering more detailed information than many other traditional spectroscopy techniques. In their work, the researchers have additionally created a way to mold the frequency combs in what they describe as a |free-form approach: Now incredibly fine command over the frequency combs lets them zero in on particular chunks of a sample’s fingerprint whilst ignoring others areas that do not provide useful data. Substances were therefore detected and measured much more quickly by the parts of the system.
Sensitive gas detection for tackling climate change
In their study, the researchers showed that their lab prototype could detect methane — a potent greenhouse gas — with a sensitivity 22 times higher than in conventional dual-comb spectrometers. This new breeder sensitivity could be used one day to detect tiny gas leaks or emissions, which may otherwise escape unnoticeably and help against climate change.
Because the method generates images of rapidly appearing methane plumes in real time, it allows scientists to pinpoint where the gas is escaping quickly — a trait that could make this technique valuable not just for finding greenhouse gases but anywhere else scientists need to find and quantify gases. The novel design can be configured to operate with a broad spectrum of laser wavelengths, yielding a flexible solution that could be used in everything from monitoring air quality to detecting hazardous compounds in food.
Opening up unimaginable Future Possibilities
For that reason, the “laser sandwich” approach described here for spectroscopy could find use in a diverse range of environmental or safety applications. In the future, it similarly has the potential to aid public health and environmental preservation by allowing more essential detection of substances such as gases.
The researchers hope to further develop their laboratory tool and gain the capability to deploy outside the lab much faster. Our system can be applied in a lot of other fields due to the adaptability that comes with it, NIST researcher Esther Baumann said. “Moving forward, we could see a new class of sensors inspired by this technology expand into air quality monitors, or food safety detectors to the way materials burn and form soot.”
