1 徐州工程学院物理与新能源学院，江苏 徐州 221018
2 江苏师范大学物理与电子工程学院江苏省先进激光材料与器件重点实验室，江苏 徐州 221116
提出了由四个不同旋转方向的氧化铟锡（ITO）螺旋子单元组成的周期性中红外宽带手性结构。模拟结果显示，通过优化子单元螺旋的圈数、螺旋半径、螺距和螺旋线半径，该结构在中红外波段实现了良好的宽带圆二向色性（CD）。与两种非旋转螺旋结构比较发现，ITO旋转螺旋结构的CD带宽更宽。在波长7.95 μm处，ITO旋转螺旋结构获得CD的最大值为0.454，CD的半峰全宽为7.5 μm，波长范围从4.1到11.6 μm。产生宽带CD的原因是四个不同旋转方向的ITO螺旋子单元之间存在较强的耦合。模拟结果还显示，在中红外波段，与金属（金和银）旋转螺旋结构相比，该ITO旋转螺旋结构表现出了良好的宽带CD，这为中红外波段宽带偏振态调控器件的设计提供了新的思路。
光学材料 氧化铟锡 旋转螺旋结构 中红外波段 手性超材料 圆二向色性 激光与光电子学进展
2022, 59(5): 0516002
Author Affiliations
Abstract
1 School of Physics and New Energy, Xuzhou Institute of Technology, Xuzhou 221018, China
2 Jiangsu Key Laboratory of Advanced Laser Materials and Devices, School of Physics and Electronic Engineering, Jiangsu Normal University, Xuzhou 221116, China
We proposed a periodic mid-infrared broadband chiral structure. Its unit cell consists of four indium tin oxide (ITO) helix subunits with different radii. The simulation results show that the flat-topped broadband circular dichroism (CD) can be achieved in the mid-infrared band by optimizing the parameters of helix structures. The simulation results also show that compared with the metallic (Ag and Au) helix structures, the ITO helix structure proposed exhibits evidently better broadband CD and optical activity, which provides a new idea for the design of broadband polarization state control devices in the mid-infrared band.
mid-infrared flat-topped broadband chiral helix metamaterial Chinese Optics Letters
2021, 19(11): 111601
Author Affiliations
Abstract
Jiangsu Key Laboratory of Advanced Laser Materials and Devices, School of Physics and Electronic Engineering, Jiangsu Normal University, Xuzhou 221116, China
We studied Goos–H nchen (GH) shifts on a reflective phase-gradient-produced metasurface. Their analytical solutions were achieved for both TE and TM polarizations utilizing the generalized Snell’s law. The calculated results show that the GH shifts are evidently affected by phase gradients and incident angles, which means that a certain range of GH shifts can be realized as long as an incident angle, phase gradient, and frequency are properly chosen. This offers an effective method for the control of GH shifts.
160.3918 Metamaterials 260.6970 Total internal reflection Chinese Optics Letters
2018, 16(6): 061602
Author Affiliations
Abstract
1 Jiangsu Key Laboratory of Advanced Laser Materials and Devices, School of Physics and Electronic Engineering, Jiangsu Normal University, Xuzhou 221116, China
2 School of Electrical and Electronic Engineering, Nanyang Technological University, 639798, Singapore
We present a tunable resonator consisting of a colossal magnetoresistant cross in which a smaller gold cross is embedded. Simulations show the resonance frequencies of the resonator move into the infrared regime when there is a change in the intensity of the external magnetic field applied to the resonator. The source of the tunability is the variance in the colossal magnetoresistance in the resonator when the intensity of the magnetic field changes, which accordingly leads to a shift in the resonance frequency. Such a method offers a new way to achieve tunability, which has potential applications in controllable photoelectric elements.
160.3918 Metamaterials 260.5740 Resonance 050.1755 Computational electromagnetic methods 260.2110 Electromagnetic optics Chinese Optics Letters
2015, 13(5): 051601
江苏省先进激光材料与器件重点实验室 物理与电子工程学院江苏师范大学, 江苏 徐州 221116
设计了一种新型电磁共振吸收超常材料。这种材料具有金属-绝缘体-金属结构特性，其顶部的金属层由四瓣扇形金块构成。模拟发现，此结构在可见光和紫外频段具有良好的电磁吸收能力，且位于四瓣扇形金块下的介质层的形状、尺寸和介电常数的变化对该材料的吸波能力具有很大的影响。当四瓣扇形金块下的介质层为同等半径的圆柱形状，材料为氧化铝，厚度一定时，结构的吸收率高于90%的相对吸收线宽达到0.76，吸收范围从可见光波段延伸至紫外光波段。该研究为电磁吸波器件的设计和制造提供了一定的理论依据。
材料 计算电磁学 超常材料 数值模拟 介质层 四扇环 吸收 光学学报
2015, 35(s1): s116003
Author Affiliations
Abstract
An asymmetric metamaterial exhibiting an analog of double electromagnetically induced transparency (EIT) in the middle-infrared region is reported. The metamaterial consists of two-layered arrays of U-shaped rings embedded in a medium, with the lower layer rotated by 90o. Our simulations demonstrate that both maximum group indexes are extremely high at the two EIT-like positions. The group index reaches about thrice the currently reported maximum value at the high-frequency EIT-like position. The transmittance at the two transparency positions also possesses extremely high Q factors, which is conducive to controlling the propagation of electromagnetic waves.
160.3918 Metamaterials 260.2110 Electromagnetic optics Chinese Optics Letters
2013, 11(5): 051602
Author Affiliations
Abstract
1 Department of Physics, Lianyungang Teachers College, Lianyungang 222006, China
2 Department of Applied Physics, Nanjing University of Science and Technology, Nanjing 210094, China
3 School of Physics and Electronic Engineering, Xuzhou Normal University, Xuzhou 221116, China
We exhibit a three-dimensional (3D) photonic nanojet based on a dielectric microsphere irradiated by a plane wave with the finite-difference time-domain (FDTD) method. We investigate the influence of the refractive index of the surrounding on the properties of the nanojet by simulating the electric field distributions in it. The simulation results show that, by optimally choosing the size of the sphere and the ratio of the refractive indices of the sphere and the surrounding, the focus point can occur just on the surface of the sphere even if the refractive index of the surrounding is changed. Additionally, the peak amplitude of the nanojet increases with increasing the refractive index of the surrounding. However, the decay length and the jet width of the nanojet decrease simultaneously. These effects may have potential applications in observation or manipulation of nano-objects such as antibodies in biology. In nanojet-enabled optical data storage, the photonic nanojet may be also helpful for improving data-storage capacities and retrieval speed by controlling the field amplitude, the decay length, and jet width of the nanojet.
光子纳米喷流 折射率 衰减长度 喷流宽度 振幅峰值 180.0180 Microscopy 290.4020 Mie theory Chinese Optics Letters
2010, 8(7): 706
Author Affiliations
Abstract
Advanced Photonics Center, School of Electronic Science and Engineering, Southeast University, Nanjing 2100962 School of Physics and Electronic Engineering, Xuzhou Normal University, Xuzhou 221116
The imaging system formed by an annular left-handed material (LHM) lens as well as the evanescent waves in the lens are simulated numerically with a finite-difference time-domain (FDTD) method. For b-a>\lambda (a and b are respectively the inner and outer radii of the annular lens, and \lambda is the wavelength), when a point source is placed at an internal grid point, we demonstrate that the evanescent waves are produced around the internal interface, and cannot propagate outwards. As for b-a<\lambda, the evanescent waves appear around both the internal and the external interfaces, which remarkably implies the coupling between the two interfaces. Hence it can be inferred that the evanescent waves around the external interface participating in the super-resolution imaging result from the coupling of the evanescent waves around the interface. Moreover, the partly uncomprehended properties of the evanescent waves in the LHM slab are also disclosed. It is conducive to understanding the evanescent waves in the LHMs further.
左手圆环形透镜 成像系统 倏逝波 160.4760 Optical properties 260.5740 Resonance 100.6640 Superresolution Chinese Optics Letters
2009, 7(2): 02134
