Near-infrared cavity enhanced absorption spectroscopy of hot water and OH in an oven and in flames

A compact diode laser operating around 1.5 mum was used to measure cavity enhanced absorption spectra of hot water molecules and OH radicals in radiative environments under atmospheric conditions. Spectra of air were measured in an oven at temperatures ranging from 300K to 1500 K. These spectra contained rovibrational lines from water and OH. The water spectra were compared to simulations from the HITRAN and HITEMP databases. Furthermore, spectra were recorded in the flame of a flat methane/air burner and in an oxyacetylene flame produced by a welding torch. The results show that cavity enhanced absorption spectroscopy provides a sensitive method for rapid monitoring of species in radiative environments.