A research team from CU Boulder and the US Department of Commerce has developed a laser system that can detect minute concentrations of harmful gases, down to parts per trillion.
The sensor uses a frequency comb laser, a device that can emit thousands of colours of light simultaneously, which was originally developed for use in optical atomic clocks.
Because different gases absorb different wavelengths of light, each molecule has a unique “fingerprint” that the laser can detect.
The team placed the gas sample between two mirrors to create an optical cavity and used a technique called optical heterodyne detection to analyze the light reflecting off the mirror.
Among other uses, the team has used the sensor to detect minute quantities of the deadly hydrogen sulfide gas in beverage cans and is now working on adapting the technology to detect COVID variants.
