Setup and evaluation of a static imaging Fourier transform spectrometer for the mid-infrared spectral range

摘要

Hyperspectral imaging is an established technique for process analysis capturing a two-dimensional spatial imageand the spectral information for each pixel simultaneously. When moderate spectral resolution is sucient, staticimaging Fourier transform spectrometers (sIFTS) can oer a viable alternative to their scanning counterparts inthe mid-infrared spectral range. Therefore, in this paper we present a sIFTS concept based on a single-mirrorinterferometer which shows no internal light losses and still works with extended light sources, achieving sucientsignal-to-noise ratios. The interferometer consists of a beam splitter, a plane mirror and a lens, which makes itboth inexpensive and relatively easy to adjust. For a proof of principle we present a transmission measurementsetup including a light source module, imaging optics and a single-mirror interferometer. The system achieves aspectral resolution of 12 cm~(-1) in a spectral range from 2700 cm~(-1) to 800 cm1, respectively from 3:7 μm to 13 μm.The spatial resolution amounts to about 10:10 lp=mm, the results for a sample containing dierent polymers showgood agreement with a laboratory FTIR spectrometer.