Author Affiliations
Abstract
1 Guangxi Key Laboratory of Precision Navigation Technology and Application, Guilin University of Electronic Technology, Guilin 541004, China
2 School of Electronic Engineering and Automation, Guilin University of Electronic Technology, Guilin 541004, China
A finite-difference-time-domain (FDTD) approach is undertaken to investigate the extraordinary optical transmission (EOT) phenomenon of Au circular aperture arrays deposited on a Bragg fiber facet for refractive index (RI) sensing. Investigation shows that the choice of effective indices and modal loss of the Bragg fiber core modes will affect the sensitivity enhancement by using a mode analysis approach. The critical parameters of Bragg fiber including the middle dielectric RI, as well as its gap between dielectric layers, which affect the EOT and RI sensitivity for the sensor, are discussed and optimized. It is demonstrated that a better sensitivity of 156 ± 5 nm per refractive index unit (RIU) and an averaged figure of merit exceeding 3.5 RIU-1 are achieved when RI is 1.5 and gap is 0.02 μm in this structure.
Optical fiber sensors surface plasmon resonance periodic array refractive index sensing finite-difference time-domain Photonic Sensors
2019, 9(4): 337
南京师范大学物理科学与技术学院, 江苏省光电技术重点实验室, 江苏 南京 210023
提出一种多圆孔周期性银膜阵列结构,并利用时域有限差分算法探究该结构的光学特性。计算结果表明,当线性偏振光入射时,该结构表面激发出表面等离激元,且纳米孔间产生了局部表面等离子体共振,使得该结构的异常透射增强。针对这一现象,通过对中心孔与边孔所呈角度、入射光偏振角度、结构参数(中心孔直径、边孔直径、结构厚度、边孔与中心孔的间距)的调控来实现结构光学透射属性的优化。此外,分析所提结构在不同环境折射率条件下透射峰的变化规律, 发现该结构也对周围的环境折射率具有较高的敏感度。因此该结构在表面等离激元滤波器和折射率传感器中具有广泛的应用前景。
传感器 周期性阵列结构 局部表面等离子体共振 表面等离激元 异常透射现象
1 上海理工大学 光电信息与计算机工程学院, 上海 200093
2 上海市现代光学系统重点实验室, 上海 200093
3 上海电力学院 计算机与信息工程学院, 上海 200090
为了得到相变温度低且性能优越的智能窗光学材料,基于时域有限差分法模拟计算了不同结构的VO2纳米周期点阵相变前后的光学特性,优选出最佳的VO2纳米周期点阵结构.采用直流磁控溅射和后退火工艺在玻璃衬底上制备VO2薄膜,再利用掩膜光刻的方法制备VO2纳米周期点阵结构,测试其组分结构,反射和透过率曲线.结果表明,填充比为0.74的圆形纳米周期点阵的相变温度有效降低了约25 ℃,在波长为1700 nm处的透过率改变量达到39 %,透过率整体高于VO2薄膜,呈现出良好的相变光学特性,说明通过调控VO2纳米周期点阵的结构可以有效提升材料的光学特性.
纳米周期点阵 光学特性 热致相变 VO2 VO2 nano periodic array optical property thermochromism
1 广西师范大学 a.电子工程学院
2 广西师范大学 b.数学与统计学院，广西 桂林 541004
设计了褶皱石墨烯波导结构激发表面等离子体激元，通过设计周期阵列结构实现了表面等离子体激元传播损耗的补偿.理论分析了周期阵列结构的表面等离子体激元传播模型和补偿损耗的方式，结果表明褶皱衍射激发表面等离子体激元波导不仅能够激发表面等离子体激元，还能利用表面等离子体激元波矢关系实现器件参数控制，周期阵列增益全程补偿损耗的方式可以显著增加表面等离子体激元的传播距离.数值分析结果进一步表明：该结构具备了保持亚波长尺寸的强局域化优势；周期阵列增益全程补偿可以显著提高纳米腔中的电场强度，降低传输损耗；波导结构的粒子反转水平较高，自发辐射噪声的扰动较低.设计的石墨烯波导器件可以为微纳光学集成、光子传感和测量等领域提供理想的亚波长光子器件.
亚波长光学 表面等离子体激元 周期褶皱结构 周期阵列结构 纳米腔 Subwavelength optics Surface plasmon polaritons Cycle fold structure Periodic array structure Nanocavities
Author Affiliations
Abstract
1 School of Engineering and Science, Victoria University, PO Box 14428,Melbourne, Victoria 8001, Australia
2 School of Physics, The University of Melbourne, Victoria 3010, Australia
3 CSIRO Materials Science & Engineering, Private Bag 33, Clayton South MDC, Victoria 3169, Australia
A finite-difference time-domain approach was used to investigate the excitation of surface plasmons of the circular sub-wavelength apertures on an optical fiber endface. This phenomenon provided the basis of a sensitive liquid refractive index sensor. The proposed sensor is compact and has the potential to be used in biomedical applications, having a sensitivity of (373 ± 16) nm per refractive index unit (RIU) as found through the variation of a reflection minimum with the wavelength.
Optical fiber surface plasmon resonance periodic array refractive index sensing finite-difference time-domain Photonic Sensors
2012, 2(3): 271
