Diode laser spectroscopy of the A1-A2 splittings in the v2 = 1 and v4 = 1 vibrational states of PH3

Abstract

Using the diode laser spectroscopy technique with Doppler limited resolution, 174 spectrum lines have been measured of the ν2 and ν4 vibration-rotational bands of PH3. The A1-A2 splittings have been resolved for the K′ = 3 (J′ = 7–15) levels in the ν2 band and for the −l, K′ = 2 (J′ = 2–11), +l, K′ = 4 (J′ = 4–14), and +l, K′ = 7 (J′ = 9–17) levels in the ν4 band. The effect of the various vibrational-rotational interactions on the A1-A2 splittings has been discussed qualitatively. It has been shown that the x-y Coriolis interaction between the v2 = 1 and v4 = 1 vibrational states enhances the A1-A2 splitting in the kl = +1 levels of the v4 = 1 state as well as in the kl = +4 and kl = +7 levels.