Light source could be used to make chip-scale gas sensors

The collaborative team from Ghent University, IMEC and the Max Planck Institute in Garching, Germany have demonstrated a new type of frequency comb light source, an extended spectrum light source that is claimed to be ideal for extremely high resolution spectroscopy.

A frequency comb is a light source with a spectrum containing thousands of laser lines. The technology, which makes it possible to establish a link between the optical and radio frequency parts of the electromagnetic spectrum, allows researchers to determine optical frequencies with unprecedented precision.

Frequency combs have already been used for a number of applications, notably in the development of highly accurate optical clocks. They have also long been thought to have great potential for spectroscopy. But until now, comb sources have not operated at the right wavelength to make this possible.

The pan European team behind the latest research believes it has made a fundamental breakthrough by developing combs that work in the mid-infrared molecular fingerprinting region of the electromagnetic spectrum. Within this wavelength region, many molecules have specific absorption bands that can be used in spectroscopy to determine the presence and concentration of these molecules in samples.