Terahertz Portable Handheld Spectral Reflection (PHASR) Scanner

• Main Authors: Zachery B. Harris, Mahmoud E. Khani, M. Hassan Arbab
• Format: Article
• Language: English
• Published: IEEE 2020-01-01
• Series: IEEE Access
• Subjects: Terahertz imaging; terahertz time-domain spectroscopy
• Online Access: https://ieeexplore.ieee.org/document/9296758/
• ISSN: 2169-3536

We report on the development and characterization of a handheld terahertz (THz) time-domain spectroscopic scanner for broadband imaging between approximately 0.25 and 1.25 THz. We designed and fabricated a 3D-printed fiber-coupled housing which provides an alignment-free strategy for the placement and operation of the THz optics. Image formation is achieved through telecentric beam steering over a planar surface through a custom f-θ scanning lens. This design achieves a consistent resolution over the full 12 × 19 mm field of view. Broadband spectral imaging is demonstrated using a 1951 United States Air Force Resolution Test Target. The consistency of the resolution over the wide field is validated through Boehler Star resolution measurements. Finally, a practical scenario of subsurface imaging on a damaged section of an aircraft wing is demonstrated. The THz PHASR is a field-deployable imaging system with the versatility to be applied to a much broader range of targets and imaging scenarios than previously possible, from industrial non-destructive testing to clinical diagnostic imaging.