Photoacoustic spectroscopy of C(2)H(4) with a tunable waveguide CO(2) laser.

A photoacoustic gas spectrometer using a wave-guide CO(2), laser, tunable over 500-MHz windows in 70 lines, is described. The spectrometer is used for mapping Doppler-limited spectral signatures of ethylene and for measuring pressure-broadening rates for collisions with N(2), Ar, and He. A total of 41 observed transitions are assigned to the nu(7), nu(10), and nu(4) bands of normal ethylene and to the nu(7) band of the (13)C(12)CH(4) isotopomer.