Sydney: Here comes an exciting new laser that can detect very low concentrations of gases – paving the way for accurately analysing breath for disease diagnosis and remote sensing of critical greenhouse gases.
The physicists at University of Adelaide in south Australia have developed a new type of laser that produces 25 times more light emission than other lasers operating at a similar wavelength.
“This laser has significantly more power and is much more efficient than other lasers operating in mid-infrared frequency range,” said Ori Henderson-Sapir, a researcher at the university’s institute for photonics and advanced sensing.
“Using a novel approach, we’ve been able to overcome the significant technical hurdles that have prevented fibre lasers from producing sufficient power in the mid-infrared,” he added.
The new laser operates in the mid-infrared frequency range – the same wavelength band where many important hydrocarbon gases absorb light.
The researchers reported light emission at 3.6 microns – the deepest mid-infrared emission from a fibre laser operating at room temperature.
“Probing this region of the electromagnetic spectrum with the high power means we will be able to detect these gases with a high degree of sensitivity,” said project leader David Ottaway.
It should enable the possibility of analysing trace gases in exhaled breath in the doctors’ surgery.
For example, acetone can be detected in the breath when someone has diabetes.
Other potential applications include detection in the atmosphere of methane and ethane which are important gases in global warming.
The new laser uses an optical fibre which is easier to work with, less bulky and more portable, and much more cost effective to produce than other types of laser.
The main limitation to date with laser detection of these gases has been the lack of suitable light sources that can produce enough energy in this part of the spectrum, explained Ottaway.
It has incredible potential for scanning for a range of gases with a high level of sensitivity, with great promise as a very useful diagnostic and sensing tool, said the study published in the journal Optics Letters.