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.
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http://dx.doi.org/10.1364/OE.26.005358 | DOI Listing |
Research (Wash D C)
January 2025
Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117583, Singapore.
Phys Chem Chem Phys
January 2025
College of Mechanics and Engineering Science, Hohai University, Nanjing, 211100, China.
Driven by the pressing demand for integration and miniaturization within the terahertz (THz) spectrum, this research introduces an innovative approach to construct chiral structures using dichroism as the target function. This initiative aims to tackle the prevalent issues of single-functionality, narrow application scope, and intricate design in conventional metasurfaces. The proposed multifunctional tunable metasurface employs a graphene-metal hybrid structure to address the critical constraints found in existing designs.
View Article and Find Full Text PDFSci Rep
January 2025
Terahertz Research Center, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, 610054, China.
Strong light-matter coupling occurs when the rate of energy exchange between the electromagnetic mode and the molecular ensemble exceeds the competitive dissipation process. Coupled photon molecules with near-field light-matter interactions may produce new hybridized states when they reach the strong coupling region. Tunable Terahertz (THz) meta materials can be used to design sensors, optical modulators, etc.
View Article and Find Full Text PDFSensors (Basel)
January 2025
Department of Optoelectronics, Center for Physical Sciences and Technology (FTMC), Saulėtekio Ave. 3, LT-10257 Vilnius, Lithuania.
The practical implementation of terahertz (THz) imaging and spectroscopic systems in real operational conditions requires them to be of a compact size, to have enhanced functionality, and to be user-friendly. This work demonstrates the single-sided integration of Fresnel-zone-plate-based optical elements with InGaAs bow-tie diodes directly on a semiconductor chip. Numerical simulations were conducted to optimize the Fresnel zone plate's focal length and the InP substrate's thickness to achieve constructive interference at 600 GHz, room-temperature operation and achieve a sensitivity more than an order of magnitude higher-up to 24.
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December 2024
Department of Optoelectronics, Center for Physical Sciences and Technology (FTMC), Saulėtekio Ave. 3, LT-10257 Vilnius, Lithuania.
Terahertz frequency range imaging has become more and more attractive for a wide range of practical applications; however, further component optimization is still required. The presented research introduces 3D-printed high-impact polystyrene (HIPS) beam-shaping components for the terahertz range. Gaussian, Bessel, and Airy beam-shaping structures are fabricated, and different combinations are employed to evaluate imaging system performance.
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