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The multicomponent gas analyzer has a wide range of applications, such as environmental monitoring, chemical reaction and industrial process control, accident prevention, exploration in the oil and gas industries, and biomedicine. Laser photoacoustic spectroscopy is the universal method for analyzing gaseous impurities due to its high selectivity, sensitivity, and fast response. This paper presents an automated gas analysis system based on the combined optical parametric oscillators tuning from 2.5 to 10.8 µm. The full width at half maximum of the spectral line is approximately 5.5 ± 0.5 cm–1 in the range from 2.5 to 4.5 μm and approximately 2 ± 0.5 cm–1 in the range from 4.5 to 10.8 μm. Using software installed on the control computer, the controller performs all necessary operations, including pumping, analysis, and removal of gas samples in the measuring complex. The paper presents experimentally recorded absorption spectra of gas mixtures of CO, CO2, and CH4 obtained using a differential photoacoustic detector. [ABSTRACT FROM AUTHOR]

We report the development of a combined optical parametric oscillator based on a fan-out MgO:PPLN crystal and a HgGa2S4 crystal, providing smooth wavelength tuning in the spectral range from 2.5 to 10.8 μm. A transversely pumped Nd:YAG laser with a pulse energy of ∼4 mJ and a spatial beam distribution described by a second-order Gaussian function along the x axis and a fourth-order Gaussian function along the y axis is used as a pump source. A maximum achievable radiation energy of the optical parametric oscillator is at a level of 360 μJ for a wavelength of 3.3 μm, 130 μJ for a wavelength of 4.73 μm, and 110 μJ for a wavelength of 7.40 μm. The developed radiation source is used to record absorption spectra of gas mixtures of methane, propane and nitrogen dioxide. [ABSTRACT FROM AUTHOR]