Abstract: A system and method are disclosed for gas sensing over a wide tunable wavelength range provided by one or more quantum cascade lasers. A laser beam is generated within the wide tunable wavelength range, which is given by the sum of the wavelength ranges from the individual lasers. Gas sensing or detection is achieved by obtaining an infrared absorption spectrum for a sample contained in one or more cells having different path lengths for the laser beam.

Abstract: A system and method are disclosed for gas sensing over a wide tunable wavelength range provided by one or more quantum cascade lasers. A laser beam is generated within the wide tunable wavelength range, which is given by the sum of the wavelength ranges from the individual lasers. Gas sensing or detection is achieved by obtaining an infrared absorption spectrum for a sample contained in one or more cells having different path lengths for the laser beam.

Abstract: A system and method are disclosed for gas sensing over a wide tunable wavelength range provided by one or more quantum cascade lasers. A laser beam is generated within the wide tunable wavelength range, which is given by the sum of the wavelength ranges from the individual lasers. Gas sensing or detection is achieved by obtaining an infrared absorption spectrum for a sample contained in one or more cells having different path lengths for the laser beam.

Abstract: Configurations herein include a novel process, system, etc., to measure a concentration of sulfur trioxide in a gas sample including sulfur trioxide, sulfur dioxide, and water. An example system can include an optical radiation source that generates an optical signal at a plurality of vibration-rotation transitions around at least one frequency selected from the group consisting of 1396.889 cm?1, 1396.908 cm?1, 1396.962 cm?1, 1397.003 cm?1, 1397.037 cm?1, 1397.047 cm?1, and 1397.052 cm?1. The optical signal is transmitted along an optical path through the gas sample. Based on adjusting a pressure of the gas sample, each of the plurality of vibration-rotation absorption transitions associated with the sulfur trioxide can be substantially isolated from interfering absorption by the sulfur dioxide and the water vapor in the gas sample. Based on a spectral analysis, the system generates a value indicative of a concentration of sulfur trioxide in the gas sample.