Attenuated total internal reflection (ATR) infrared mapping microspectroscopy of soft samples is reviewed and investigated by using cartridge-based germanium hemispheres. The study demonstrates the use of these devices for obtaining line scans or maps of soft pliable surfaces over an area of approximately 100 X 100 micrometers. An experimental determination of the spatial resolution by using a cross-sectioned polymer film showed a twofold improvement over transmission infrared microspectroscopy for sample sizes at the diffraction limit. Optical details of the devices are discussed in the context of ATR measurements in addition to their application for the study of polymer laminates often encountered in industry and forensics.
Lori L. Lewis and Andre J. Sommer, "Attenuated Total Internal Reflection Infrared Mapping Microspectroscopy of Soft Materials," Appl. Spectrosc. 54, 324-330 (2000)