title: Diffraction-limited real-time terahertz imaging by optical frequency up-conversion in a DAST crystal.
abstract: Real-time terahertz (THz) wave imaging has wide applications in areas such as security, industry, biology, medicine, pharmacy, and the arts. This report describes real-time room-temperature THz imaging by nonlinear optical frequency up-conversion in an organic 4-dimethylamino-N'-methyl-4'-stilbazolium tosylate (DAST) crystal, with high resolution reaching the diffraction limit. THz-wave images were converted to the near infrared region and then captured using an InGaAs camera in a tandem imaging system. The resolution of the imaging system was analyzed. Diffraction and interference of THz wave were observed in the experiments. Videos are supplied to show the interference pattern variation that occurs with sample moving and tilting.
authors.forename: Shuzhen
authors.initials: S
authors.lastname: Fan
authors.forename: Feng
authors.initials: F
authors.lastname: Qi
authors.forename: Takashi
authors.initials: T
authors.lastname: Notake
authors.forename: Kouji
authors.initials: K
authors.lastname: Nawata
authors.forename: Yuma
authors.initials: Y
authors.lastname: Takida
authors.forename: Takeshi
authors.initials: T
authors.lastname: Matsukawa
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Minamide