Wide band (2.5 GHz) infrared heterodyne spectrometer

Conclusion A double beam heterodyne spectrometer with 2.5 GHz bandwidth was built in Reims. The receiver's bandwidth was measured by heterodyning radiation from a CO₂ laser with the radiation from a tunable diode laser. The spectrometer was used for laboratory studies. Ammonia absorption spectra were recorded. Line positions in agreement with other works were measured.This apparatus will soon be used for atmospheric ozone studies in association with an isotopic¹²C¹⁸O₂ laser to avoid atmospheric CO₂ absorption.