Infrared diode laser spectroscopy of the △ν = 2 band of AlF

A vibrational-rotational spectrum of the △ν = 2 transitions of a high-temperature molecule AlF was observed between 1490 and 1586 cm−1 with a diode laser spectrometer. Measurements were made on the ν = 3-1, 4-2, 5-3 and 8-6 bands at a temperature of 900 °C. Measured spectral lines were fitted to effective band constants ν0, Bν and Dν for each band. Present measurements were made with only one Pb-salt laser diode. Physical significance of the effective band constants is discussed.