TRIPLE MODULATION EXPERIMENT FOR A FOURIER TRANSFORM SPECTROMETER

摘要

For a step-scanning Fourier transform spectrometercomprising an interferometer, a detector, and a digital signalprocessor (DSP), a method for measuring a response of a sampleto multiple modulations is disclosed. In one embodiment, themethod comprises the steps of utilizing the DSP to measure aphase modulation angle and a sample modulation angle; obtainan interferogram that corresponds to a calibrated staticsample response by using the measured phase modulationrotation angle; obtain another interferogram which correspondsto the calibrated dynamic sample response by using both themeasured phase and sample modulation rotation angles; andcomputing one or more spectra from the interferograms whichindicates the calibrated response of said sample to themultiple modulations.