Article
Optics
Lifei Wei, Huamao Huang
Summary: In this work, a triple-band large-spatial-separation beam splitter at visible wavelengths is proposed using a phase-gradient metasurface in both the x-and y-directions. Under x-polarized normal incidence, the blue light is split in the y-direction into two equal-intensity beams due to resonance inside a single meta-atom, the green light is split in the x-direction into another two equal-intensity beams due to the size variation between adjacent meta-atoms, while the red light passes directly without splitting. The size of the meta-atoms is optimized based on their phase response and transmittance. The simulated working efficiencies under normal incidence are 68.1%, 85.0%, and 81.9% at wavelengths of 420 nm, 530 nm, and 730 nm, respectively. The sensitivities of the oblique incidence and polarization angle are also discussed.
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION
(2023)
Article
Engineering, Multidisciplinary
Hang Chen, Jianan Feng, Minwei Jiang, Yiqun Wang, Jie Lin, Jiubin Tan, Peng Jin
Summary: This study extends the diffractive deep neural network (DNN)-N-2 to visible wavelengths and proposes a general theory to solve contradictions between wavelength, neuron size, and fabrication limitations. The novel visible light (DNN)-N-2 classifier successfully recognizes handwritten digits and altered targets.
Article
Multidisciplinary Sciences
Meng-Hsin Chen, Cheng-Wei Yen, Chia-Chun Guo, Vin-Cent Su, Chieh-Hsiung Kuan, Hoang Yan Lin
Summary: The study introduces a new design of high-efficiency metalenses using hexagon-resonated elements to achieve high performance and polarization insensitivity. By choosing metalenses at the desired wavelength, it is possible to efficiently observe the structures on patterned substrates, avoiding the need for expensive equipment.
SCIENTIFIC REPORTS
(2021)
Article
Optics
Guozhen Liang, Heqing Huang, Aseema Mohanty, Min Chul Shin, Xingchen Ji, Michael Joseph Carter, Sajan Shrestha, Michal Lipson, Nanfang Yu
Summary: The study presents visible-spectrum silicon nitride thermo-optic phase modulators based on adiabatic micro-ring resonators, which offer a one-order-of-magnitude reduction in both device footprint and power consumption compared to waveguide phase modulators. These modulators provide 1.6 pi phase modulation with minimal amplitude variations and improved robustness against fabrication variations.
Article
Chemistry, Multidisciplinary
Xinzhi Zheng, Yujie Ma, Chenxi Zhao, Bingxi Xiang, Mingyang Yu, Yanmeng Dai, Fang Xu, Jinman Lv, Fei Lu, Cangtao Zhou, Shuangchen Ruan
Summary: This paper investigates a new polarization-splitting mechanism based on the energy distributions of the fundamental polarized modes in the r-TiO2 ridge waveguide. The bending losses for different bending radii and the optical coupling properties of the fundamental modes in different r-TiO2 ridge waveguide configurations are analyzed. A polarization splitter with high extinction ratio operating at visible wavelengths based on directional couplers (DCs) in the r-TiO2 ridge waveguide is proposed. Polarization-selective filters based on micro-ring resonators (MRRs) with resonances of only TE or TM polarizations are designed and operated. The results show that polarization splitters for visible wavelengths with high extinction ratio in DC or MRR configurations can be achieved with a simple r-TiO2 ridge waveguide structure.
Article
Chemistry, Multidisciplinary
Trevon Badloe, Inki Kim, Yeseul Kim, Joohoon Kim, Junsuk Rho
Summary: Researchers demonstrated an electrically controllable bifocal metalens at visible wavelengths, with liquid crystals for actively manipulating the focal length. The metalens showed highly efficient focusing performance with a measured focusing efficiency of around 44%, and could switch focus between two designed focal planes through electrical modulation.
Article
Nanoscience & Nanotechnology
Xing Liu, Qinghua Liang, Xiaochen Zhang, Chang-Yin Ji, Jiafang Li
Summary: The nano-kirigami method allows for a wide range of structural geometries in optical micro/nano-devices, enhancing their functionalities. However, the current methodologies are limited, which hampers the utilization of chiral nano-kirigami structures in the visible wavelength region. In this study, various nano-kirigami strategies are comprehensively explored to demonstrate a bio-inspired nano-cilia metasurface with enhanced circular dichroism at visible wavelengths. By using electron-beam lithography and focused ion beam lithography, on-chip nano-cilia metasurfaces are successfully realized and validate the giant circular dichroism observed in simulations. This work expands the platform of micro/nano-scale manufacturing and provides an effective method for creating versatile bioinspired nanostructures with significant chiroptical responses.
Article
Chemistry, Multidisciplinary
Tian Tian, Yuheng Chen, Jie Zhang, Shuolin Wang, Wen Yuan, Hongde Liu, Yaoqing Chu, Chengling Mao, Wenjie Xu, Dahuai Zheng, Jiayue Xu
Summary: A series of uranium-doped lithium niobate crystals (LN:U) were grown by the modified vertical Bridgman method, and their photorefractive properties in the visible band were systematically investigated for the first time. The occupancy of uranium ions and photorefractive centers is discussed. LN:U achieves multi-wavelength holography.
Article
Optics
K. A. Hallman, L. Rodriguez-Sune, J. Trull, C. Cojocaru, M. A. Vincenti, N. Akozbek, R. Vilaseca, M. Scalora
Summary: Nonlinear silicon photonics offers unique abilities to generate, manipulate, and detect optical signals in nano-devices. The inefficiency of nonlinear processes, absorption, and the lack of realistic models have been limiting the nano-engineering of silicon. This study presents measurements of second and third harmonic generation from undoped silicon membranes, providing insights into the nonlinear optical properties of complex structures and the potential of exploiting nonlinear dispersion of semiconductors.
Article
Optics
Rashmi Kumari, Shubhanshi Sharma, Shailendra Kumar Varshney, Basudev Lahiri
Summary: In this paper, we present the concept of a dual-channel optical metasurface switch operating at telecommunication wavelengths. The switch utilizes two pairs of asymmetric silicon nanobars stacked vertically with each pair acting as optical resonators to produce two Fano resonant peaks. By changing the Fermi potential of the graphene sheet beneath each optical resonator, the Fano resonances of the silicon nanobars can be independently tuned between ON and OFF states. We demonstrate four possible combinations for both types of optical resonators, ON-ON, ON-OFF, OFF-ON, and OFF-OFF, depending on the potential applied to the corresponding graphene sheet.
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS
(2023)
Article
Nanoscience & Nanotechnology
Yue Yu, Lai Wang, Xiankai Sun
Summary: The study explored the acousto-optic effect of lithium niobate on a chip at near-visible wavelengths, demonstrating acousto-optic modulation with a modulation frequency up to 2.44 GHz. The device fabrication used an etchless process and the optimization of device performance was achieved by applying the principle of bound states in the continuum.
Article
Materials Science, Multidisciplinary
Babak Vosoughi Lahijani, Nicolas Descharmes, Raphael Barbey, Gael D. Osowiecki, Valentin J. Wittwer, Olga Razskazovskaya, Thomas Sudmeyer, Hans Peter Herzig
Summary: This article investigates the propagation properties of optical modes supported at the free surface of a 1D photonic crystal. Structures optimized for long-distance propagation of optical surface waves are designed and fabricated, and the existence of optical surface waves in the visible spectral range is experimentally demonstrated for the first time.
ADVANCED OPTICAL MATERIALS
(2022)
Article
Optics
Sangwon Baek, Jae Yong Park, Jong-Lam Lee
Summary: The study demonstrates a multiwavelength metalens that operates concurrently at three visible wavelengths, designed by integrating metalens components using SIM or SLAM methods. The metalenses achieved near diffraction-limited focusing efficiency at wavelengths of 400, 600, and 800 nm, providing a simple guideline to increase the operating wavelengths of metalenses.
Article
Optics
David A. Coucheron, Oystein Helle, James S. Wilkinson, Ganapathy Senthil Murugan, Carlos Dominguez, Hallvard Angelskar, Balpreet S. Ahluwalia
Summary: On-chip super-resolution optical microscopy relies on waveguide excitation with visible light. Tantalum pentoxide and silicon nitride waveguide platforms were investigated for background with different excitation wavelengths, showing that silicon nitride has progressively stronger background with shorter wavelengths. Higher background from silicon nitride at shorter wavelengths reduces localization precision for single molecule detection, recommending tantalum pentoxide for shorter wavelength applications.
Article
Physics, Applied
Si Xiao, Hao Xin, HaiMing Ma, Chang Wang, Ying Ma, Jun He
Summary: The optical nonlinear absorption and refraction of spherical MoS2/TiO2 nanocomposites were investigated using Z-scan and spatial self-phase modulation techniques. The study found that the nanocomposites exhibited enhanced two-photon absorption with high photon energy excitation and tunable saturated single-photon absorption with low photon energy excitation. Additionally, the nanocomposites showed enhanced spatial self-phase modulation signal with long wavelength in the visible band.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Multidisciplinary Sciences
Z. H. Fang, H. Chen, F. S. Yang, C. R. Luo, X. P. Zhao
SCIENTIFIC REPORTS
(2016)
Article
Physics, Condensed Matter
Guoli Sun, Huan Chen, Suna Cheng, Xiaopeng Zhao
PHYSICA B-CONDENSED MATTER
(2017)
Article
Biochemistry & Molecular Biology
Suna Cheng, Di An, Huan Chen, Xiaopeng Zhao
Article
Multidisciplinary Sciences
Zhen-Hua Fang, Huan Chen, Di An, Chun-Rong Luo, Xiao-Peng Zhao
SCIENTIFIC REPORTS
(2018)
Article
Chemistry, Multidisciplinary
Huan Chen, Jing Zhao, Zhenhua Fang, Di An, Xiaopeng Zhao
ADVANCED MATERIALS INTERFACES
(2019)
Article
Biochemistry & Molecular Biology
Huan Chen, Di An, Xiaopeng Zhao
Article
Physics, Condensed Matter
Huan Chen, Xiaopeng Zhao
PHYSICA B-CONDENSED MATTER
(2020)
Article
Nanoscience & Nanotechnology
Jing Zhao, Huan Chen, Kun Song, Liqin Xiang, Qian Zhao, Chaohong Shang, Xiaonong Wang, Zhijie Shen, Xianfeng Wu, Yajie Hu, Xiaopeng Zhao
Summary: This study reports an ultralow loss isotropic metamaterial for visible light and investigates its inverse Doppler effect. By using ball-thorn-shaped metaclusters with a super-thin silver layer, it has been possible to measure the negative refractive index and the inverse Doppler effect of visible light. The discrete super-thin silver layer produced by the photoreduction method significantly reduces energy losses, opening up possibilities for the fabrication of arbitrary-shaped, low-loss isotropic three-dimensional metamaterial devices.
Article
Optics
Xin Chen, Chunsheng Xu, Shan Liu, Dawei Liu, Bihui Tan, Yi Zhang, Huan Chen, Yan Sheng, Junli Wang
Summary: In this study, the optical induction of ferroelectric domain inversion on the -z surface of lithium niobate crystals using a 1035 nm femtosecond fiber laser was demonstrated. The effects of laser power and focusing parameters on domain morphology were investigated. It was found that different power levels and lens focusing could lead to irregular or regularly arranged domains with varying sizes.
