The low-noise current controller delivers stable power to sensors that use quantum cascade lasers to analyze very small gas concentrations.

A low-noise current controller developed at DOE's Pacific Northwest National Laboratory was recently licensed to Wavelength Electronics Inc. (Bozeman, MT). The device delivers stable and reliable power to the lasers used in gas sensors, for use in analyzing trace atmospheric gases.

Scientists often analyze 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 airplanes. The sensor instrument directs a laser through the sample, and based on how much laser light is absorbed by the sample, scientists can determine the specific gases present and their concentrations.

Smaller concentrations of certain gases can be challenging to analyze. 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.

The PNNL device reduces the noise on the laser's power source, allowing scientists to detect smaller levels of trace gases. PNNL's controller is the lowest noise controller on the market that was specifically designed for extra-sensitive sensors that use quantum cascade lasers (QCLs). Sensors made with QCLs emit light in a wavelength region that many trace gases strongly absorb.

Wavelength Electronics Inc. is planning to launch products that incorporate PNNL's low-noise current controller technology by the end of the year.