Source Code and Simulation Results: Chiral and directional optical emission from a dipole source coupled to a helical plasmonic antenna

Summary This publication supplements the article "Chiral and directional optical emission from a dipole source coupled to a helical plasmonic antenna" with tabulated data and Matlab code that allows the reproduction of the results. Within the article, the chiral behavior of single and double plasmonic nano antennas made from silver is numerically investigated with a focus on the coupling of a linear polarized dipole as an excitation source to the helix. Simulation Setup - FEM Simulations The script "run_wavlengthscan.m" allows to reproduce all simulations of the article. It can be chosen between the single and double helices, by specifying the keys parameter "keys.doppelhelix" where 0 gives a single and 1 a double helix. The number of turns can be specified by choosing "keys.case". The dipol is located within a 20nm thick hBN substrate layer, on glass (BK7). Results of the Purcell enhancement can be plotted using the scripts "display_results_single_helix.m" and "display_results_doublehelix.m" in the folder "results". The far-field plots can be reproduced using the scripts "display_farfiel_polarization_single_helix.m" and "display_farfiel_polarization_double_helix.m" of the folder "FunctionsAndScripts". The template for the mesh is contained in the folder "generate_grid_file", where the parameters of the helix (for example: radius, tube radius, and pitch height) can be modified. Within the folder "project3D" all required .jcm files are stored. Copy the "grid.jcm" file with the geometry of interest to this folder to perform simulations. All required keys parameters for the JCM template files (.jcmt, jcmpt) are set within the functions "set_numerical_parameter.m" and "set_physical_parameters.m", contained in the folder "FunctionsAndScripts". Therein, the function "set_sources.m" specifies the parameters for the dipole excitation, such as the position, and the strength (equivalent to the polarization). Material The material data has been taken from the refractiveindex.info database. For silver the data is taken from tabulated data from Johnson and Christy [1] . The dispersion relation for hBN comes from [2] and tabulated data for glass (BK7) from [3]. The MATLAB script "material_properties_plot.m" plots the material fits above the wavelengths of interest. The required tabulated data is given in the folder "material_data". With 'material_properties_plot.m' the fits to the material data can be reproduced and plotted. Usage The .zip folder Helix_FEM contains all data and scripts to reproduce the plots from the 3D FEM simulations. Requirements JCMsuite (at least 5.4.0) MATLAB (tested with version R2023b) To run the simulations with JCMsuite you must replace corresponding placeholders with a path to your installation of JCMsuite. Free trial licenses are available, please refer to the homepage of JCMwave. References [1] P. B. Johnson and R.-W. Christy, “Optical constants of the noble metals,” Phys. Rev. B 6, 4370 (1972). [2] S.-Y. Lee, T.-Y. Jeong, S. Jung, and K.-J. Yee, “Refractive index dispersion of hexagonal boron nitride in the visible and near-infrared,” Phys. Status Solidi B 256, 1800417 (2019).[3] “SCHOTT Zemax catalogue 2017-01-20b,” (2017).## 概述 本数据集补充了题为"与螺旋等离激元天线耦合的偶极源的手性定向光发射"的学术论文，提供了可复现该论文研究结果的表格化数据与MATLAB代码。论文中针对银制单螺旋与双螺旋等离激元纳米天线的手性特性开展了数值研究，重点探究了作为激发源的线偏振偶极子与螺旋结构的耦合过程。 ## 仿真设置——有限元法（Finite Element Method，FEM）仿真 脚本`run_wavlengthscan.m`可复现论文中的全部仿真计算。通过指定参数`keys.doppelhelix`可选择单螺旋或双螺旋结构：取值0对应单螺旋，1对应双螺旋。螺旋的圈数可通过参数`keys.case`进行设置。偶极子置于玻璃（BK7）衬底上的20nm厚六方氮化硼（hexagonal boron nitride，hBN）衬底层中。珀塞尔增强的结果可通过`results`文件夹下的`display_results_single_helix.m`与`display_results_doublehelix.m`脚本进行绘图。远场偏振分布图可通过`FunctionsAndScripts`文件夹下的`display_farfield_polarization_single_helix.m`与`display_farfield_polarization_double_helix.m`脚本复现。 网格模板存储于`generate_grid_file`文件夹中，可在此修改螺旋结构的各项参数，如半径、管半径与螺距高度。 `project3D`文件夹中存储了所有所需的`.jcm`格式文件。将包含目标几何结构的`grid.jcm`文件复制至该文件夹，即可开展仿真计算。 JCM模板文件（`.jcmt`与`.jcmpt`）所需的全部参数均在`FunctionsAndScripts`文件夹下的`set_numerical_parameter.m`与`set_physical_parameters.m`函数中完成配置。其中，`set_sources.m`函数用于配置偶极子激发的相关参数，包括位置与强度（等效于偏振方向）。 ## 材料参数 材料光学参数取自refractiveindex.info数据库。其中银的光学常数数据来自Johnson与Christy的制表结果[1]，六方氮化硼（hBN）的色散关系取自文献[2]，玻璃（BK7）的表格化光学参数取自文献[3]。MATLAB脚本`material_properties_plot.m`可绘制目标波长范围内的材料参数拟合曲线。所需的表格化数据存储于`material_data`文件夹中。通过`material_properties_plot.m`脚本，可复现并绘制材料参数的拟合结果。 ## 使用说明 本数据集的压缩包`Helix_FEM.zip`包含了复现三维有限元法（FEM）仿真绘图所需的全部数据与脚本。 ## 运行依赖 - JCMsuite（版本不低于5.4.0） - MATLAB（已在R2023b版本中完成测试） 使用JCMsuite运行仿真前，需将脚本中的占位符替换为本地JCMsuite的安装路径。可申请免费试用许可证，详情请访问JCMwave官方主页。 ## 参考文献 [1] P. B. Johnson 与 R.-W. Christy，"贵金属的光学常数"，《物理评论B》，第6卷，第4370页（1972年）。 [2] S.-Y. Lee、T.-Y. Jeong、S. Jung 与 K.-J. Yee，"可见光与近红外波段六方氮化硼的折射率色散"，《固态物理学报B》，第256卷，第1800417页（2019年）。 [3] "SCHOTT Zemax产品目录2017-01-20b"，2017年。