| 题名 | 亚波长周期金属结构中光传输特性的研究 |
| 作者 | 汪丽春 |
| 学位类别 | 博士 |
| 答辩日期 | 2010 |
| 授予单位 | 中国科学院上海光学精密机械研究所 |
| 导师 | 龚尚庆 |
| 关键词 | 表面等离子体激元 亚波长金属光栅 时域有限差分 严格耦合波分析 |
| 其他题名 | Investigation of light transmission in subwavelength periodically structured metallic films |
| 中文摘要 | 亚波长周期性金属结构中光的超强透射以及聚束效应的发现为在纳米范围内进行光束控制提供了新的契机，其机理和应用研究是目前国际现代光学领域研究工作的一个热点。 本论文首先利用严格耦合波分析（RCWA）方法理论研究了表面等离子体模式之间耦合对超强透射的影响，并利用时域有限差分（FDTD）算法精确计算了表面周期调制连续金属薄膜的透射效率，详细讨论了各种表面等离子体（SPP）模式对超强透射的贡献，利用表面等离子体的局域特性设计了控制透射光束出射方向及时域形状的纳米金属透镜。具体研究内容如下： 1．利用RCWA分析近似解析处理一维金属光栅结构，基于光栅狭缝中有效耦合模式的考虑，讨论了金属上下表面以及光栅内壁表面等离子体模式之间耦合对超强透射的影响，发现在Wood异常处出现了透射峰，且在平板金属表面等离子体激发波长附近出现了能量禁带； 2．利用FDTD算法研究了表面周期调制的连续金属薄膜中光的透射，分别对单表面调制和双表面调制情况作了讨论，发现对单个表面进行周期调制的金属薄膜，在平板金属表面等离子体激发波长处透过率几乎为零，对双表面同时调制的金属膜，上下表面SPP的共振隧穿耦合导致超强透射； 3．基于金属亚波长周期结构的超强透射和聚焦特性，研究了包覆克尔介质的金属光栅对透射光束的方向控制，数值仿真了金属纳米透镜对出射光束的时域脉冲形状调制； 4．基于表面等离子体模式之间的匹配达到有效耦合，提出了设计金属亚波长周期结构实现近场纳米光束方向控制的理论方案，利用FDTD数值仿真模拟了出射面刻有周期槽的单缝金属薄膜结构对透射光束的聚束现象，与理论预测结果相一致。 |
| 英文摘要 | Since its discovery in 1998, the phenomenon of extraordinary optical transmission has aroused a renewed interest in the optical properties of subwavelength metallic structure. The phenomena dealing with extraordinary transmission and directional beaming of light through subwavelength metallic structures has attracted much attention due to their fundamental importance for manipulating light at a subwavelength scale. There has been a worldwide interest to research on its physics mechanism and its application. In this paper, the Rigorous Coupled Wave Analysis (RCWA) and Finite-Difference and Time-Domain (FDTD) method are employed to analyze the extraordinary optical transmission (EOT) on the periodically modulated subwavelength metallic structure. The main content is as follows: 1. We analyszed the optical property of 1-D metallic grating by RCWA, and discussed the effect of coupled surface plasmons on the transmission. It is found that transmission is enhanced at Wood’s anomalies; In addition, dents appeared for a wavelength range slightly shorter than the surface plasmon resonances. 2. The optical transmission through periodically modulated continuous metallic film is investigated by FDTD method. We found that the excitation of surface plasmon on the smooth surface leads to nearly zero transmittance when the metal is grooved on a single surface. Resonant tunneling coupling of surface plasmon polaritons (SPPs) on the two interfaces leads to extraordinary transmission when both surfaces are grooved. 3. We demonstrated that a finite number of subwavelength slits can realize beam splitting and focusing of light by coating the metallic film surfaces with nonlinear Kerr material. The femtosecond pulse through a nano-slit lens can be focused on a nano scale spot, while the pulse shape well maintained. 4. We proposed a design scheme for directional beaming of optical field from a nanoslit in metallic film flanked by dielectric surface gratings on the output side. Based on the effective coupling of slit surface plasmon cavity-mode and the metallic-dielectric-air waveguide mode, directional beaming of light can be realized by tuning the geometrical parameters. A numerical simulation based on the finite-difference time-domain method was also undertaken, the results obtained match well with our theoretical prediction. |
| 语种 | 中文 |
| 内容类型 | 学位论文 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/15299]  |
| 专题 | 上海光学精密机械研究所_学位论文 |
| 推荐引用方式 GB/T 7714 | 汪丽春. 亚波长周期金属结构中光传输特性的研究[D]. 中国科学院上海光学精密机械研究所. 2010. |
| 个性服务 |
| 查看访问统计 |
| 相关权益政策 |
| 暂无数据 |
| 收藏/分享 |
除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。
修改评论