title: High-speed terahertz reflection three-dimensional imaging using beam steering.
abstract: High-speed terahertz (THz) reflection three-dimensional (3D) imaging is demonstrated using electronically-controlled optical sampling (ECOPS) and beam steering. ECOPS measurement is used for scanning an axial range of 7.8 mm in free space at 1 kHz scan rate while a transverse range of 100 × 100 mm(2) is scanned using beam steering instead of moving an imaging target. Telecentric f-θ lenses with axial and non-axial symmetry have been developed for beam steering. It is experimentally demonstrated that the non-axially symmetric lens has better characteristics than the axially symmetric lens. The total scan time depends on the number of points in a transverse range. For example, it takes 40 s for 200 × 200 points and 10 s for 100 × 100 points. To demonstrate the application of the imaging technique to nondestructive testing, THz 3D tomographic images of a glass fiber reinforced polymer sample with artificial internal defects have been acquired using the lenses for comparison.
authors.forename: Dae-Su
authors.initials: DS
authors.lastname: Yee
authors.forename: Kyong Hwan
authors.initials: KH
authors.lastname: Jin
authors.forename: Ji Sang
authors.initials: JS
authors.lastname: Yahng
authors.forename: Ho-Soon
authors.initials: HS
authors.lastname: Yang
authors.forename: Chi Yup
authors.initials: CY
authors.lastname: Kim
authors.forename: Jong Chul
authors.initials: JC
authors.lastname: Ye