title: Spatial pattern separation of chemicals and frequency-independent components by terahertz spectroscopic imaging.
abstract: We separated the component spatial patterns of frequency-dependent absorption in chemicals and frequency-independent components such as plastic, paper, and measurement noise in terahertz (THz) spectroscopic images, using known spectral curves. Our measurement system, which uses a widely tunable coherent THz-wave parametric oscillator source, can image at a specific frequency in the range 1-2 THz. The component patterns of chemicals can easily be extracted by use of the frequency-independent components. This method could be successfully used for nondestructive inspection for the detection of illegal drugs and devices of bioterrorism concealed, e.g., inside mail and packages.
authors.affiliation: RIKEN, 2-1 Hirosawa, Wako, 351-0918, Japan. ywata@postman.riken.go.jp
authors.forename: Yuuki
authors.initials: Y
authors.lastname: Watanabe
authors.forename: Kodo
authors.initials: K
authors.lastname: Kawase
authors.forename: Tomofumi
authors.initials: T
authors.lastname: Ikari
authors.forename: Hiromasa
authors.initials: H
authors.lastname: Ito
authors.forename: Youichi
authors.initials: Y
authors.lastname: Ishikawa
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Minamide