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.