QUADRUPOLE HYPERFINE AND A1-A2 SPLITTING IN THE UPSILON-2 FUNDAMENTAL OF ARSINE

We have investigated the saturation spectrum of the ν2 fundamental of arsine. AsH3, at 906.75157863 (85) cm-1 with a resolution of 200 kHz. CO2 laser sidebands at microwave modulation frequencies were used for the measurements between 890 and 988 cm-1. Quadrupole hyperfine structure as well as vibration-rotation splitting of K = 3 and K = 6 levels have been investigated. In addition, an interaction between these two effects has been observed. Both effects have been included into the diagonalization of the energy matrix. The standard deviation of the fit, including MW and RF data, is Ill kHz. This work was partly undertaken to contribute to calibration standards for Fourier transform and diode laser spectrometers. © 1994 Academic Press. All rights reserved.