Investigation of the broadening of absorption lines of molecular gases by methods of pulsed laser diode spectroscopy

A study was made of the use of middle-infrared pulsed laser diodes in investigations of the width and profile of absorption lines of molecular gases. Broadening of the absorption lines of CF₂Cl₂ and SF₆ located in the region of 930 cm^–1 was studied by correlation processing of the laser diode spectra. The coefficient representing the broadening of the CF₂Cl₂ lines in air depended on the buffer gas pressure and it increased from 5.7 to 12.9 MHz/Torr when this pressure was increased from 0 to 100 Torr. The broadening coefficient of the ³²SF₆ lines by helium was independent of the He pressure in the range 5–100 Torr and amounted to 6 MHz/Torr. The self-broadening coefficients of NH₃ and CF₂Cl₂ were found to be 28.5 and 31.2 MHz/Torr.