title: Time-reversal and model-based imaging in a THz waveguide.
abstract: We investigate two approaches to improving the resolution of time-reversal based THz imaging systems. First, we show that a substantial improvement in the reconstruction of time-reversed THz fields is achieved by increasing the system's numerical aperture via a waveguide technique adapted from ultrasound imaging. Second, a model-based reconstruction algorithm is developed as an alternative to time-reversal THz imaging and its performance is demonstrated for cases with and without a waveguide.
authors: Center for Ultrafast Optical Science, University of Michigan, 2200 Bonisteel Boulevard, Ann Arbor, Michigan 48109-2099, USA. mmushein@umich.edu
authors: Malakeh A
authors: MA
authors: Musheinesh
authors: Charles J
authors: CJ
authors: Divin
authors: Jeffrey A
authors: JA
authors: Fessler
authors: Theodore B
authors: TB
authors: Norris
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007089:Image Enhancement / Q000295:instrumentation* / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000295:instrumentation* / Q000379:methods*; D008027:Light; D008962:Models, Theoretical; D055096:Optical Devices; D012542:Scattering, Radiation; D055069:Terahertz Imaging / Q000295:instrumentation* / Q000379:methods; D055053:Terahertz Radiation