Interferogram amplitude modulation technique for selective detection of transient species with a continouus-scan Fourier-transform spectrometer

A new interferogram amplitude modulation (IAM) technique for a Fourier-transform spectrometer with a continuous-scan interferometer was devised. This technique is useful for selective detection of transient species produced in ac discharge plasmas. Infrared emission spectra due to the Δν = 1 bands of the vibrationally excited CO molecule, the fundamental band of the OH radical, and the 5g-4f band of Rydberg H2 were recorded to demstrate selectivity of this method.