Abstract-Guided terahertz pulse reflectometry with double photoconductive antenna

Mingming Pan, Quentin Cassar, Frédéric Fauquet, Georges Humbert, Patrick Mounaix, and Jean-Paul Guillet

https://www.osapublishing.org/ao/abstract.cfm?uri=ao-59-6-1641

Developments toward the implementation of a terahertz pulse imaging system within a guided reflectometry configuration are reported. Two photoconductive antennas patterned on the same LT-GaAs active layer in association with a silica pipe hollow-core waveguide allowed us to obtain a guided optics-free imager. Besides working in a pulsed regime, the setup does not require additional optics to focus and couple the terahertz pulses into the waveguide core, simplifying the global implementation in comparison with other reported guided terahertz reflectometry systems. The system is qualified for imaging purposes by means of a 1951 USAF resolution test chart. An image resolution, after a 53 mm propagation length, by about 0.707 LP/mm over the 400–550 GHz integrated frequency band, was obtained, thus providing a promising basis to pursue efforts toward compact guided pulse imagers for sample inspection within the terahertz range.

© 2020 Optical Society of America

Abstract-Terahertz frequency modulated continuous wave imaging advanced data processing for art painting analysis

Corinna L. Koch Dandolo, Jean-Paul Guillet, Xue Ma, Frédéric Fauquet, Marie Roux, and Patrick Mounaix

https://www.osapublishing.org/oe/abstract.cfm?uri=oe-26-5-5358

Reflection terahertz frequency modulated continuous waves scanner (300 GHz) has been proficiently optimized for imaging two easel paintings of different age. The information content of the obtained THz images has been fully inspected by selecting the appropriate THz image parameter. At the same time, a new data processing has been developed for improving the level of detail held by the axial parametric THz images by means of Gaussian fit of the reflected signals. By carefully weighting the reflected signals as a function of the optical path, the reflected amplitude has been corrected for the positioning of the object surface with respect to the beam focal point. The artifact affecting the THz images recorded from an uneven painting surface have been resolved and the obtained images fairly represent to the original painting.

© 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement