中国矿业大学信息与控制工程学院,江苏 徐州 221116
提出了一种基于电磁诱导透明(EIT)的多功能偏振无关超表面,其基础结构由1个金属十字结构和4个方环结构组成,并引入了可调控材料硅(Si)以及二氧化钒(VO2),以实现温光双控。利用模拟计算和理论模型分析得到了基础结构作为双明模间接耦合形成EIT透明窗口的结论。由于EIT以及可调控材料的特性,本设计可以在分子传感、可控慢光以及双通道温光双控开关等领域实现应用,并且具有优异的性能。该结构对蔗糖溶液的传感灵敏度为97.6 GHz/(kg/m3),在分子检测领域展示出了巨大潜力。该结构实现了对慢光效应的可选择控制。依据EIT的作用机理,提出了利用可调控材料改变结构谐振进而控制电磁响应的设计思路,并实现了一种双通道温光双控开关,为今后的EIT超表面设计提供了参考。
表面光学 超表面 可调控材料 分子传感 慢光效应 温光双控开关
Author Affiliations
Abstract
School of Information and Control Engineering, China University of Mining and Technology, Xuzhou 221116, China
Toroidal multipole is a special current distribution that has many different characteristics from electric multipole and magnetic multipole distributions. Because of its special properties, the toroidal dipole is a research hotspot in the field of metamaterials and nanophotonics. However, the low scattering of the toroidal dipole moment makes its excitation a challenging task. At present, there are relatively few studies on its specific engineering applications. In this paper, by slotting in the rectangular cavity, the excitation of an equivalent toroidal dipole is successfully achieved over a wide frequency range of 53–58 GHz. Results indicate that under the action of the toroidal dipole, the mode electromagnetic waves transmitted in the rectangular waveguide are converted into vector beams and are radiated outwards. Further adjusting the spatial distribution of the magnetic dipoles in the toroidal dipoles yields results that indicate that the resonance mode in the slot is still dominated by the magnetic toroidal dipole moment, and the electromagnetic waves radiating outward are vortex beams carrying vector polarization. The scattered energy of each dipole moment inside the antenna is calculated. This calculation verifies that the mass of the vector beam and vector vortex beam is closely related to the toroidal dipole supported by this antenna. The proposed structure can be applied to explorations in vortex filtering, in photon entanglement, and in the photonic spin Hall effect.
toroidal dipole vector beams vector vortex beams Chinese Optics Letters
2024, 22(1): 011601
1 中国矿业大学教育部地下空间智能控制工程研究中心,江苏 徐州 221116
2 中国矿业大学信息与控制工程学院,江苏 徐州 221116
设计了一种可由空间编码结构光控制的多功能太赫兹超表面单元,该单元由嵌有光敏半导体材料的金属裂环-二氧化硅介质层-金属底板组成。超表面单元通过结构光源的编码控制光改变单元顶层金属裂环内嵌光敏半导体的电导率来模拟不同形状的C形环,实现了具有2 bit相位编码的光控超表面单元设计。将超表面单元组成阵列,通过编码结构光的空间分布进一步实现了角度可控的异常反射,并获得不同阶数的涡旋波束。所提出的基于空间编码结构光源的新型太赫兹超表面光控方式解决了现有光控超表面功能单一、加工难度大等问题,为光控可编程太赫兹超表面技术发展提供了新的思路。
表面光学 太赫兹 光控超表面 可编程超表面 结构光 波束控制 光学学报
2023, 43(11): 1124004
1 中国矿业大学地下空间智能控制教育部工程研究中心,江苏 徐州 221116
2 中国矿业大学信息与控制工程学院,江苏 徐州 221116
基于Fano共振超表面所具有的高品质因数以及电场局域特性设计了一种全介质超表面结构,探究了超表面结构参数与品质因数、调制深度之间的关系。通过改变结构实现了单重Fano共振至双重Fano共振的有效调控。对比同等参数下矩形柱与椭圆柱超表面结构的灵敏度,选择矩形柱结构并确定其最优参数。矩形柱超表面结构的品质因数最大可达3408,双重共振峰的调制深度接近99%。通过仿真计算可知该结构对甲烷体积分数的测量灵敏度可以达到(对应dip1)和(对应dip2),对背景折射率的测量灵敏度为和,FOM(figure of merit)值分别为和。此外,入射光偏振角度对此传感结构的Fano共振透射光谱强度具有一定影响,这一特性为光学非对称传输、偏振角检测以及超表面多功能复用等提供了新思路。
传感器 Fano共振 全介质超表面 甲烷传感器 偏振敏感 光学传感器 中国激光
2023, 50(10): 1010001
1 梧州学院电子与信息工程学院,广西 梧州 543001
2 桂林电子科技大学机电工程学院,广西 桂林 531004
3 中国矿业大学信息与控制工程学院,江苏 徐州 221116
4 阿尔伯塔大学电子与计算机工程系,阿尔伯塔 埃德蒙顿 T6G 1H9,加拿大
5 青岛农业大学理学与信息科学学院,山东 青岛 266109
海上红外目标识别在海事搜寻中发挥着重要的作用,针对逆光海况下出现的目标反向对比度特点及其目标淹没于背景的问题,结合其直方图呈现的局部尖峰特点,提出了修正灰度占比的新直方图均衡化并融合边缘信息的增强算法。该算法可以有效地提升目标区域的对比度,从而提升海上红外图像的质量。在海上红外目标识别与检测中,建立了目标与背景的多尺度“九宫格”搜索框,演化了局部对比度显著性量化的数学模型,实现了符合人眼视觉特性的红外目标的准确定位与检测。在海上红外图像增强测试中,所提算法可以使原图像的平均梯度提升两倍以上,使局部对比度增益因子提升两倍以上。在目标识别的算法测试中,所提多尺度局部对比度目标检测算法可以使目标检测率达到99%以上。
测量 红外成像 海上红外目标识别 红外图像增强 直方图变换 局部对比度显著性 逆光海况
Author Affiliations
Abstract
1 School of Information and Control Engineering, China University of Mining and Technology, Xuzhou 221116, China
2 Engineering Research Center of Intelligent Control for Underground Space (Ministry of Education), China University of Mining and Technology, Xuzhou 221116, China
A new D-shaped tellurite photonic crystal fiber sensor based on the four-wave mixing (FWM) effect with the surface plasmon resonance (SPR) effect is designed and optimized. The substrate of the D-shaped photonic crystal fiber (D-PCF) is tellurite glass, and the polished surface is plated with the gold film and hydrogen gas-sensitive film. An air hole of the inner cladding, which is plated with the gold film and methane gas-sensitive film, is selected as the second sensing channel to simultaneously measure the concentration of hydrogen and methane. Based on the four-wave mixing, the wavelength shifts of the Stokes and anti-Stokes spectra resulting from the variation of the gas concentration can be used to accurately detect the concentrations of methane and hydrogen. Meanwhile, it is found that the SPR effect can increase the wavelength shifts, which means the sensitivity of methane and hydrogen augment. After parameter optimization, the maximum sensitivities of methane and hydrogen are 4.03 nm/% and -14.19 nm/%, respectively. Both the linearities are up to 99.9%. The resolution of methane is 1.25×10-2% and hydrogen is 7.14×10-3%. Moreover, the fiber length of this sensor is only 20 mm, which is conducive to the construction of a compact or ultra-compact embedded FWM fiber sensor.
Four-wave mixing surface plasmon resonance D-shaped photonic crystal fiber gas sensing Photonic Sensors
2023, 13(1): 230121
强激光与粒子束
2023, 35(2): 025001
北方民族大学化学与化学工程学院, 银川 750021
本文使用两步法, 通过控制PbI2(DMSO)溶液的浓度制备了不同厚度的有机-无机杂化钙钛矿(MAPbI3)光吸收层薄膜, 并组装了大面积基于碳电极且无空穴传输层的钙钛矿太阳能电池。对不同厚度MAPbI3光吸收层薄膜的晶相、光吸收性质、表面形貌、元素组成进行分析, 并进一步测试了基于MAPbI3薄膜制备的钙钛矿太阳能电池的光伏性能。结果表明, MAPbI3光吸收层薄膜厚度与PbI2(DMSO)浓度呈正相关关系, 浓度为1.3 mol/L的PbI2溶液制备的MAPbI3薄膜厚度约为350 nm, 具有较好的结晶度和光吸收强度, 且薄膜表面致密平整, 无明显缺陷, 基于350 nm MAPbI3光吸收层的钙钛矿太阳能电池获得了8.48%的光电转换效率。
碳电极 钙钛矿 太阳能电池 无空穴传输层 光吸收层 光伏性能 carbon electrode perovskite solar cell hole-free transport layer optical absorption layer photovolatic performance