High-resolution diode-laser spectroscopy of the 9492 cm^−1 band of ethylene

High-resolution absorption spectra within the central maximum of the ν7 band of C2H4 have been recorded using tunable semiconductor lasers. 169 individual transitions have been resolved in three nonoverlapping frequency regions covering approximately 97% of the spectral range from 947.1 to 951.9 cm−1. The frequency splittings between individual transitions are reproducible to ±0.008 cm−1 or better. The problems of scanning an extended frequency range with a multiplicity of diode lasers arise primarily from limited laser-tuning range and the lack of appropriate techniques for precise absolute frequency calibration. The strengths and weaknesses of diode lasers in high-resolution molecular spectroscopy are assessed.