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The vortex beam (Laguerre-Gaussian, LG mode) is employed to alleviate crystal damage in multiple-plate continuum generation. We successfully compressed 190-fs, 1030-nm pulses to 42 fs with 590 μJ input pulse energy, which is 5.5 times higher than that obtained by a Gaussian beam setup of the same footprint. High throughput (86%) and high intensity-weighted beam homogeneity (>98%) have also been achieved. This experiment confirms the great potential of beam shaping in energy up-scaling of nonlinear pulse compression.
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http://dx.doi.org/10.1364/OL.465661 | DOI Listing |
Microsyst Nanoeng
September 2025
Center for Terahertz Waves, College of Precision Instrument and Optoelectronics Engineering, and the Key Laboratory of Optoelectronics Information and Technology (Ministry of Education), Tianjin University, Tianjin, 300072, China.
Terahertz communication systems demand versatile devices capable of simultaneously controlling propagating waves and surface plasmon polaritons (SPPs) in far-field (FF) and near-field (NF) channels, yet existing solutions are constrained by volatile operation, single-function limitations, and the inability to integrate NF and FF functionalities. Here, we present a nonvolatile reconfigurable terahertz metasurface platform leveraging the phase-change material GeSbTe(GST) to achieve on-demand dual-channel modulation-a first in the terahertz regime. By exploiting the stark conductivity contrast of GST between amorphous and crystalline states, our design enables energy-efficient switching between NF-SPP manipulation and FF-wavefront engineering without requiring continuous power input.
View Article and Find Full Text PDFNanophotonics
August 2025
Key Laboratory of Opto-Electronics Information Technology (Tianjin University), Ministry of Education, School of Precision Instruments and Opto-Electronics Engineering, Tianjin, 300072, China.
Vortex beams, characterized by orbital angular momentum (OAM), hold significant potential in optical communications, quantum information processing, and optical manipulation. However, existing metasurface designs are largely confined to single-degree-of-freedom control, such as static OAM generation or fixed focal points, which limiting their ability to integrate polarization multiplexing with dynamic focal tuning. To address this challenge, we propose a tunable multifunctional cascaded metasurface that synergizes polarization-sensitive phase engineering with interlayer rotational coupling, overcoming conventional device limitations.
View Article and Find Full Text PDFNat Commun
September 2025
State Key Laboratory of Precision Measurement Technology and Instruments, Tianjin University, Tianjin, China.
Phased arrays are crucial in various technologies, such as radar and wireless communications, due to their ability to precisely control and steer electromagnetic waves. This precise control improves signal processing and enhances imaging performance. However, extending phased arrays to the terahertz (THz) frequency range has proven challenging, especially for high-frequency operation, broadband performance, two-dimensional (2D) phase control with large antenna arrays, and flexible phase modulation.
View Article and Find Full Text PDFNat Commun
August 2025
Institute of Acoustics, Tongji University, Shanghai, China.
Chiral vortex beams with tunable topological charges (TCs) hold promise for high-capacity and multi-channel information transmission. However, asymmetric vortex transport, a crucial feature for enhancing robustness and security, often disrupts channel independence by altering TCs, causing signal distortion. Here, we exploit the radial mode degree of freedom in chiral space to achieve extremely asymmetric transmission with high energy contrast, while preserving chirality and TCs.
View Article and Find Full Text PDFOrbital angular momentum (OAM) beams have brought the nonlinear light-matter interaction to a novel, to our knowledge, regime. In this work, we investigate the generation of high-order harmonics in atomic gases when the extreme nonlinear optical process is driven by the coaxial superposition of linearly polarized Laguerre-Gaussian (LG) modes. Specifically, we discuss the cases when the waist sizes of the two superposed LG modes are different (double-ring vortex beam) or the same (optical ring lattice).
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