Component spatial pattern analysis of chemicals by use of two-dimensional electro-optic terahertz imaging.

We demonstrate a method of chemical mapping by using the transillumination terahertz (THz) images obtained by two-dimensional electro-optic THz imaging. The images and spectral data were measured between 0.1 and 1.0 THz. An experimental sample consisting of three chemicals was prepared, with one in two concentrations. By introducing the component spatial pattern analysis based on the least-squares method, the chemical composition, spatial distribution, and difference in concentration were clearly determined.