Intracavity Laser Absorption Spectroscopy and Fourier Transform Spectrum of the 3ν1 band region of cyanoacetylene

Abstract The second CH stretching overtone of cyanoacetylene, HC 3 N, near 9700 cm −1 has been recorded by Fourier Transform Spectroscopy (FTS) and by Intracavity Laser Absorption Spectroscopy (ICLAS) with a Vertical External Cavity Surface Emitting Laser (VECSEL). In total thirteen bands have been identified in the highly congested spectra and rotationally assigned. Their rovibrational spectroscopic parameters have been obtained from a fit of the line centers.