Current sensor aids TAG analysis

The low-noise current controller was developed at the US Department of Energy’s Pacific Northwest National Laboratory. The technology was recently licensed to Bozeman, Montana-based Wavelength Electronics by Battelle, which operates PNNL for the UD Department of Energy (DOE).

Scientists often analyse atmospheric gas concentrations with laser-based sensors. Researchers sample air at sites of interest, such as on the ground near power plants or at high altitudes from aircraft. The sensor instrument then directs a laser through the sample. Based on how much laser light is absorbed by the sample, scientists can determine the specific gases present and their concentrations.

But smaller concentrations of certain gases can be challenging to analyse. One particular problem occurs when ’noises’, or random fluctuations, exist in a laser’s wavelength and line width. Such noise prevents researchers from making precise readings.

PNNL scientists reduced this problem by developing a low-noise current controller. The device reduces the noise on the laser’s power source, allowing scientists to detect smaller levels of trace gases. The controller is claimed to be the lowest noise controller on the market specifically for extra-sensitive sensors that use quantum-cascade lasers, also called QCLs.