Analytical 4D Infrared Tomography Using an InSb Focal Plane Array Sensor. 1. 3D Infrared Tomography (Single-Wavelength Approach)

A combined mid-IR and near-IR camera with focal plane InSb detector array has been applied to remote, noninvasive, infrared tomographic analysis of turbid, three-dimensional macroscopic polymer bodies. Tomographic infrared images were recorded under distinct, equidistant angular views of samples mounted at a rotating sample holder. Hidden metallic, nonmetallic, and liquid samples inside the turbid hollow polymer body have been three-dimensionally reconstructed by using the tomographic back-projection computer algorithm. Radiation penetrated samples up to 2 × 1.5 mm thickness. Potential chemical−analytical applications of quantitative infrared tomography as a new technology to noninvasive 3D analysis of polymers, glasses, tablets and drugs, and turbid liquids were discussed theoretically.