Fourier-transform instrument for high-resolution Raman spectroscopy of gases.
An instrument is described for recording vibrational-rotational Raman spectra of gases with a resolution of 0.02-0.03 cm(-1). The Raman scattered light is collected by near forward scattering within the cavity of a single-mode, long-term, stabilized Ar-ion laser. The Raman light is analyzed in an ordinary step-scanned Michelson interferometer. To compensate for the low intensity of vibrational-rotational Raman spectra, the interferometer has a beam diameter of 160 mm. The movable mirror, weighing 2.7 kg, is mounted on a smoothly moving sledge, the stepwise motion being performed by three piezotranslators and controlled by three independent He-Ne laser beams. It is shown experimentally that it is possible for one to move the mirror with sufficient precision, using only 13% of the scan time in a typical experiment. In a preliminary spectrum of the fundamental vibration of(14) N(2), the width of the lines has been measured to 0.015 cm(-1).
Bendtsen
J
J
Rasmussen
F
F
Brodersen
S
S