Intracavity laser absorption spectroscopy near 9400 cm−1 with a Nd:glass laser: application to 14N2 16O

A new compact and low-power-consuming cw intracavity laser absorption spectroscopy (ICLAS) spectrometer with a broad tunability near 1.06 μm has been developed. This ICLAS spectrometer uses a thin plate of Nd:glass as the amplification medium and allows pumping by a laser diode. The absorption spectrum of nitrous oxide 14N2 16O has been recorded near 9400 cm−1 with this new ICLAS apparatus. It reveals an extremely weak absorption band centred at 9398.848 cm−1. The corresponding upper term value, vibrational assignment and Bv rotational constant, as well as the band intensity, are quantitatively discussed in the frame of the vibrational cluster model. The observed atmospheric spectrum in the region is assigned to H2 16O and discussed.