Tunable diode laser absorption spectroscopy

Materials science

Chromatography

Infrared

Optical fiber

Photoacoustic spectroscopy

Wavelength

Saturation (graph theory)

Diode

Laser

Physics

Mathematics

Optics

Analytical Chemistry (journal)

Tunable laser

Combinatorics

Chemistry

Photoacoustic imaging in biomedicine

Detection limit

Optoelectronics

Sensors and Actuators B Chemical

A photoacoustic sensor system for the ppb-level CO detection of sulphur hexafluoride (SF6) decomposition was developed by use of a 10 W fiber-amplified near-infrared (NIR) diode laser. A photoacoustic detection module with symmetrical construction was designed to allow a high power laser beam and a large gas flow. A theoretical model was developed to describe the dynamic equilibrium processes of CO molecular activation and deactivation in the presence of gas flow. The 10 W optical excitation power effectively compensates the CO weak absorption line strength in the NIR spectral region and realizes a saturation-free CO detection with the assistance of the gas flow, resulting in a ppb-level CO detection sensitivity, which is comparable with the detection sensitivity obtained using a mid-infrared CO sensor.

Ppb-level photoacoustic sensor system for saturation-free CO detection of SF6 decomposition by use of a 10 W fiber-amplified near-infrared diode laser