A reflective terahertz phase shifter for wide-range dynamic and continuous phase modulation is proposed. By injecting a tunable liquid crystal between the slotted metasurface and the grating microstructure, the phases of reflected waves can be modulated with different electrically driven methods. Numerical simulations show that the proposed terahertz phase shifter has a phase difference of more than 360° between unbiased and biased states. Furthermore, an array of 35×35 patch elements was designed and fabricated. The performance of the phase shifter provides more than 360° between 379.6 and 391.8 GHz, where the maximum phase shift reaches 422.4° at 385.9 GHz. Moreover, the fully electrically controlled phase modulation of more than 180° is achieved between 382.0 and 394.1 GHz, with a maximum phase modulation of 248.4° at 383.3 GHz. This work may provide a reflective terahertz phase modulator for beam steering.
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http://dx.doi.org/10.1364/AO.470935 | DOI Listing |
Science
January 2025
Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany.
Chirality, a pervasive form of symmetry, is intimately connected to the physical properties of solids, as well as the chemical and biological activity of molecular systems. However, inducing chirality in a nonchiral material is challenging because this requires that all mirrors and all roto-inversions be simultaneously broken. Here, we show that chirality of either handedness can be induced in the nonchiral piezoelectric material boron phosphate (BPO) by irradiation with terahertz pulses.
View Article and Find Full Text PDFLow-temperature phase (β-form) barium borate (BBO) is one of the most important nonlinear crystals that has been widely used for optical second-harmonic generation (SHG), especially with femtosecond sources. There was growing interest in its applications in the direct generation of terahertz (THz) radiations, but it was hindered by the lack of knowledge of its basic properties in the THz range. In a recent study based on first-principles quantum chemistry calculation, we found that the theoretically calculated refractive indices of β-BBO in the THz frequency range do not agree with the previously reported values.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Terahertz Research Center, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu 611731, China.
Low-dimensional materials (LDMs) with unique electromagnetic properties and diverse local phenomena have garnered significant interest, particularly for their low-energy responses within the terahertz (THz) range. Achieving deep subwavelength resolution, THz nanoscopy offers a promising route to investigate LDMs at the nanoscale. Steady-state THz nanoscopy has been demonstrated as a powerful tool for investigating light-matter interactions across boundaries and interfaces, enabling insights into physical phenomena such as localized collective oscillations, quantum confinement of quasiparticles, and metal-to-insulator phase transitions (MITs).
View Article and Find Full Text PDFSci Rep
January 2025
School of Electronic Science and Engineering, Xiamen University, Xiamen, 361005, China.
Metasurfaces have exhibited excellent capabilities in controlling main characteristics of electromagnetic fields. Thus, a lot of significant achievements have been attained in many areas especially in the fields of hologram and near-field imaging. However, some of these designs are implemented in a manner of interleaved subarrays that complicates the design and makes them difficult to achieve integration.
View Article and Find Full Text PDFNano Lett
January 2025
State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China.
Optical computing, renowned for its light-speed processing and low power consumption, typically relies on the coherent control of two light sources. However, there are challenges in stabilizing and maintaining high optical spatiotemporal coherence, especially for large-scale computing systems. The coherence requires rigorous feedback circuits and numerous phase shifters, introducing system instability and complexity.
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