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Your search keyword '"Chen, Qi-Dai"' showing total 457 results
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457 results on '"Chen, Qi-Dai"'

2. Reconfigurable Meta-Radiator Based on Flexible Mechanically Controlled Current Distribution in Three-dimensional Space

Author

Wu, Nan-Shu, Xu, Su, Ge, Xiao-Liang, Liu, Jian-Bin, Ren, Hang, Xu, Kuiwen, Wang, Zuojia, Gao, Fei, Chen, Qi-Dai, and Sun, Hong-Bo

Subjects
Physics - Applied Physics, Physics - Optics
Abstract

In this paper, we provide an experimental proof-of-concept of this dynamic 3D current manipulation through a 3D-printed reconfigurable meta-radiator with periodically slotted current elements. By utilizing the working frequency and the mechanical configuration comprehensively, the radiation pattern can be switched among 12 states. Inspired by maximum likelihood method in digital communications, a robustness-analysis method is proposed to evaluate the potential error ratio between ideal cases and practice. Our work provides a previously unidentified model for next-generation information distribution and terahertz-infrared wireless communications.

Published
2023

4. Inert gas as electronic impurity in semiconductors: The case for active infrared absorption in silicon

Author

Chen, Nian-Ke, Gao, Yu-Chen, Zhao, Ji-Hong, Li, Chun-Hao, Chen, Qi-Dai, Sun, Hong-Bo, Zhang, Shengbai, and Li, Xian-Bin

Subjects
Condensed Matter - Materials Science
Abstract

Inert (noble gas) elements are extremely inactive to surrounding chemical environment and are frequently employed as protective gas in various semiconductor fabrication processes. In this work, we surprisingly discover that high doses of argon up to $10^{17}-10^{20} cm^{-3}$ can be measured in silicon exposed by laser pulses even after 1300 days. First-principles calculations and molecular dynamics identify a unique argon-locking-vacancy (ALV) defect atomic model in silicon. The ALV defect is dynamically robust in contrast to the frequently moving pure Si vacancy. While argon is chemically inert, it readily modulates defect states of the occupied vacancy via steric repulsion and rattling motions, leading to significant band splitting within bandgap and thus strong infrared absorptions. Moreover, the repulsion between substitutional argon and dangling bonds results in shallow donors which explains the confusion of enhanced n-type carriers in experiments. The work paves a way of using noble gas element to produce active infrared absorption source for the non-heteroepitaxy photonic detectors directly on silicon wafer at infrared communication wavelength.

Published
2023
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6. Non-Abelian braiding on photonic chips

Author

Zhang, Xu-Lin, Yu, Feng, Chen, Ze-Guo, Tian, Zhen-Nan, Chen, Qi-Dai, Sun, Hong-Bo, and Ma, Guancong

Subjects
Physics - Optics
Abstract

Non-Abelian braiding has attracted significant attention because of its pivotal role in describing the exchange behaviors of anyons--a candidate for realizing quantum logics. The input and outcome of non-Abelian braiding are connected by a unitary matrix which can also physically emerge as a geometric-phase matrix in classical systems. Hence it is predicted that non-Abelian braiding should have analogues in photonics, but a feasible platform and the experimental realization remain out of reach. Here, we propose and experimentally realize an on-chip photonic system that achieves the non-Abelian braiding of up to five photonic modes. The braiding is realized by controlling the multi-mode geometric-phase matrix in judiciously designed photonic waveguide arrays. The quintessential effect of braiding--sequence-dependent swapping of photon dwell sites is observed in both classical-light and single-photon experiments. Our photonic chips are a versatile and expandable platform for studying non-Abelian physics, and we expect the results to motivate next-gen non-Abelian photonic devices., Comment: 6 pages, 4 figures

Published
2021
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7. Polarization-Orthogonal Nondegenerate Plasmonic Higher-Order Topological States

Author

Li, Yuanzhen, Xu, Su, Zhang, Zijian, Yang, Yumeng, Xie, Xinrong, Ye, Wenzheng, Xue, Haoran, Wang, Zuojia, Chen, Qi-Dai, Sun, Hong-Bo, Li, Erping, Chen, Hongsheng, and Gao, Fei

Subjects
Physics - Optics, Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

Photonic topological states, providing light-manipulation approaches in robust manners, have attracted intense attention. Connecting photonic topological states with far-field degrees of freedom(DoFs) has given rise to fruitful phenomena. Recently emerged higher-order topological insulators (HOTIs), hosting boundary states two or more dimensions lower than those of bulk, offer new paradigms to localize/transport light topologically in extended dimensionalities. However, photonic HOTIs have not been related to DoFs of radiation fields yet. Here, we report the observation of polarization-orthogonal second-order topological corner states at different frequencies on a designer-plasmonic Kagome metasurface in the far field.Such phenomenon stands on two mechanisms, i.e., projecting the far-field polarizations to the intrinsic parity DoFs of lattice modes and the parity splitting of the plasmonic corner states in spectra. We theoretically and numerically show that the parity splitting originates from the underlying inter-orbital coupling. Both near-field and far-field experiments verify the polarization-orthogonal nondegeneratesecond-order topological corner states. These results promise applications in robust optical single photon emitters and multiplexed photonic devices., Comment: 18 pages, 4 figures

Published
2021

16. Nanofabrication of Lithium Niobate Anti‐Reflective Subwavelength Structures for High Power Mid‐Infrared Lasers.

Author

Zheng, Jia‐Xin, Liu, Xue‐Qing, Tian, Ke‐Shuai, Li, Hong‐Yu, Zhang, Xin, Tian, Zhen‐Nan, Qian, Meng‐Dan, Wang, Lei, and Chen, Qi‐Dai

Subjects
OPTICAL parametric oscillators, HIGH power lasers, LITHIUM niobate, FEMTOSECOND lasers, NANOFABRICATION
Abstract

Lithium niobate (LN) crystal with anti‐reflective subwavelength structures (ASSs) has great applications in high‐power tunable optical parametric oscillator (OPO) lasers. However, it is still a great challenge to 3D nanofabrication of LN ASSs. Herein, a wet‐etching‐assisted laser polarization domain inversion (WE‐LPDI) technology is proposed to fabricate periodic cone arrays with a period from 200 nm to 4 µm on LN. Based on the optimized structural parameters, large‐area LN ASSs with a period of 1.3 µm and a height of 1.7 µm were fabricated on LN, which exhibits an average transmittance of 3–5 µm increasing from 78% to 85% and a highest transmittance of 88% at 5 µm. It has been demonstrated that the LN ASSs show high stability under high‐temperature and high‐power laser irradiation, which shows potential applications for high‐power mid‐IR lasers. The results indicate that the WE‐LPDI technology provides a novel way for 3D nanofabrication of LN. [ABSTRACT FROM AUTHOR]

Published
2024
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20. Enhancing Infrared Photodiode Performance by Femtosecond Laser Hyperdoping

Author

Dong, Meng-Di, Li, Chao, Zhu, Jun-Jie, Zhao, Ji-Hong, Chen, Zhan-Guo, and Chen, Qi-Dai

Abstract

As one of the most abundant elements in the Earth’s crust, semiconductor silicon has become the core material for microelectronics and optoelectronics. The silicon-based infrared (IR) photodetector can overcome the shortcomings of traditional IR materials in terms of manufacturing cost, environmental friendliness, and compatibility with the complementary metal-oxide–semiconductor (CMOS) technology. However, the band structure of silicon limits its application in IR photodetection, which is of great significance for silicon-based optoelectronic integrations. Ultrafast pulsed laser hyperdoping can extend the absorption to IR wavelengths below the bandgap of silicon. In this article, using femtosecond laser irradiation process, we fabricated inert argon-hyperdoped black silicon, whose absorption wavelength has been extended to 2500 nm. The combination of hyperdoping, laser ablation, and geometric microstructures enhances sub-bandgap absorption of argon-hyperdoped black silicon even though after thermal annealing. The argon-hyperdoped silicon photodiodes are fabricated based on metal-black silicon (n+)-silicon (n) double junctions, and the photodetector shows favorable photoresponse to 1310-nm IR light under both forward and reverse biases. The inert argon-hyperdoped black silicon, with lower ionized impurity scattering, shows a potential application in IR photodetection.

Published
2024
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24. Femtosecond Laser 3D Nano‐Printing for Functionalization of Optical Fiber Tips.

Author

Bian, Peng, Hu, Zhi‐Yong, An, Ran, Tian, Zhen‐Nan, Liu, Xue‐Qing, and Chen, Qi‐Dai

Subjects
MICROSENSORS, OPTICAL fibers, FIBER optical sensors, OPTICAL fiber detectors, OPTICS
Abstract

Functionalized optical fiber tips featuring miniature sizes and diverse functions have broken the limitations of traditional optical fiber with fixed shapes and single materials, significantly enriching the application scenarios in communication, sensing, imaging, and other fields. However, the unconventional shape presents challenges in manufacturing arbitrarily sophisticated 3D micro/nano structures on optical fiber tips. Femtosecond laser 3D nano‐printing (FL‐3DNp) technology injects new vitality into the functionalization of fiber tips due to its high‐precision, customizable structure, and real 3D processing abilities, as well as advantages of non‐vacuum, maskless, and plentiful materials. This paper extensively compares the key performance parameters of various micro‐nano manufacturing technologies for functionalizing optical fiber probes and focuses on the FL‐3DNp technology. In addition, the latest research progresses are systematically presented from the perspective of structure and application. Finally, the current research challenges and future development directions in this emerging field are discussed, aiming at providing scientific and industrial guidance for FL‐3DNp in functionalizing optical fibers. [ABSTRACT FROM AUTHOR]

Published
2024
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32. Etching-assisted femtosecond laser modification of hard materials

Author

Liu Xue-Qing, Bai Ben-Feng, Chen Qi-Dai, and Sun Hong-Bo

Subjects
femtosecond laser, hard materials, wet etching, dry etching, Optics. Light, QC350-467
Abstract

With high hardness, high thermal and chemical stability and excellent optical performance, hard materials exhibit great potential applications in various fields, especially in harsh conditions. Femtosecond laser ablation has the capability to fabricate three-dimensional micro/nanostructures in hard materials. However, the low efficiency, low precision and high surface roughness are the main stumbling blocks for femtosecond laser processing of hard materials. So far, etching-assisted femtosecond laser modification has demonstrated to be the efficient strategy to solve the above problems when processing hard materials, including wet etching and dry etching. In this review, femtosecond laser modification that would influence the etching selectivity is introduced. The fundamental and recent applications of the two kinds of etching assisted femtosecond laser modification technologies are summarized. In addition, the challenges and application prospects of these technologies are discussed.

Published
2019
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36. Polarization-Orthogonal Nondegenerate Plasmonic Higher-Order Topological States

Author

Li, Yuanzhen, primary, Xu, Su, additional, Zhang, Zijian, additional, Yang, Yumeng, additional, Xie, Xinrong, additional, Ye, Wenzheng, additional, Liu, Feng, additional, Xue, Haoran, additional, Jing, Liqiao, additional, Wang, Zuojia, additional, Chen, Qi-Dai, additional, Sun, Hong-Bo, additional, Li, Erping, additional, Chen, Hongsheng, additional, and Gao, Fei, additional

Published
2023
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