Name: determination of the excitation and coupling rates between light emitters and surface plasmon polaritons
Uploaded: 2018-07-21T12:30:00.000+00:00
Duration: 7 min 39 s
Description: Watch this Scientific Journal Video about Determination of the Excitation and Coupling Rates Between Light Emitters and Surface Plasmon Polaritons at JoVE.com

这项研究是由香港中文大学通过直接拨款4053077及4441179、研资局具竞争性的专用研究资助、402812及14304314及卓越 AoE/P-02/12。

1. 干涉光刻的设置
注: 干涉光刻用于制造周期阵列12。图 1所示的示意图设置如下:
<ol><li>将 325 nm 激光从 HeCd 多模激光器集中到 13X UV 物镜上, 并通过50微米的基于针孔的空间滤波器进行模式清洗。</li>
	<li>将两个2.5 厘米直径的虹膜30厘米分开, 进一步过滤发散光的中心区域。第二个虹膜后, 光束直径等于2.5 厘米, 并随着距离的增长非常缓慢, 这是 < 3 厘米在1米距离从第二个虹膜。假定光线几乎是准直的。 注意: 在肉眼检查时, 第二虹膜的输出应该是均匀的。</li>
	<li>将准直光束转向劳埃德的镜面干涉仪。劳埃德的设置包含一个棱镜为基础的样本持有人和一个5.04 厘米的镜子定位垂直于它。直接和反射的照明一起创建一个稳定的驻波沿样品表面的模式。棱镜作为一种减反射装置。 注意: 常设波浪的期间 P 可以被写作为: <img alt="Equation 9" src="/files/ftp_upload/56735/56735eq9.jpg"> </img>, λ = 325 毫微米和α是事件角度关于样品法线, 如图 1所示。通过旋转劳埃德的设置, 可以调整事件的角度。</li>
</ol>2. 周期性阵列准备
注: 样品是根据制造商建议的标准程序编制的。所有的程序都是在室温下进行的。
<ol><li>使用1厘米2玻璃基板。在超声波浴中, 用甲醇和丙酮清洁玻璃10分钟, 然后在200摄氏度的热板上预焙1小时以去除污垢。</li>
	<li>自旋涂层的玻璃基板与5毫微米厚粘附层和 100 nm 厚负 SU-8 光刻胶与双速自旋涂布机。<ol>
<li>用伽玛丁内稀释 SU-8 光刻胶, 其比例为 1:5 (v/v), 使厚度可以控制在自旋涂层后接近 100 nm。</li>
		<li>在玻璃基板上分配3-5 滴 (0.2 毫升) 的附着力溶液, 并在十年代和3600转每分钟 600 rpm 旋转, 连续的1分钟。</li>
		<li>重复步骤2.2.2 与 5-7 (0.3 毫升) 滴稀释 SU-8 从步骤2.2.1 以相同的速度。 注: 附着力层提高了玻璃基板和光刻胶之间的附着力, 使光刻胶在显影过程中不会脱落。SU-8 层厚度由自旋涂布机的浓度和速度控制。</li>
	</ol>
</li>
	<li>焙样品在65°c 和95°c 烤盘为1分钟每。这里不推荐使用烤箱。</li>
	<li>将样品转移到干涉仪中的棱镜上。添加一滴折射率匹配油 (n = 1.45), 以附加样品在棱镜上。把它尽可能靠近镜子。 注: 由于油的表面张力, 试样附着在棱镜表面。油的折射率选择与棱镜和玻璃基片相同, 以消除干涉的反反射。</li>
	<li>对于二维正方形晶格, 用相同曝光时间但正交方向公开两次样品;即, 暴露样品, 然后旋转它的90°第二次曝光。当光刻胶暴露在325纳米光, 它 crosslinks, 不能被 SU-8 开发人员溶解。 注: 可通过调整曝光时间来控制阵列的直径 D。</li>
	<li>硬烤样品在65°c 和95°c 2 分钟, 以防止薄膜开裂。</li>
	<li>将整个样品浸入显影液中2分钟, 连续搅拌以溶解未暴露区域。</li>
	<li>将样品浸泡在异丙醇中1分钟, 冲洗残留物, 然后用压缩空气将其烘干。然后生成一个 nanohole 数组。</li>
</ol>3. 金膜沉积和光发射涂层
<ol><li>将样品附着在带双双面胶带的射频磁控溅射沉积系统样品架上, 用于金膜沉积。</li>
	<li>用涡轮分子泵将腔体向下泵入 2x10-6乇基压, 然后再用 6x10-3乇超高纯度氩气填充。</li>
	<li>使用5厘米直径 99.9% Au 目标, 并在样品和目标之间放置一个快门。使用低功耗 (50 W) 降低沉积速率以及表面粗糙度。随着快门关闭, 预先溅射目标10分钟, 以清除污垢。</li>
	<li>打开快门, 在室温下处理沉积物20分钟。薄膜厚度为100毫微米定期存放, 以确保等离子系统是光学上厚, 没有传输。</li>
	<li>一旦样品准备就绪, 旋转涂层的发光材料, 如有机染料或量子点在金属表面形成薄层的电介质。<ol>
<li>对于参考9中使用的苯乙烯8染料, 将聚乙烯醇聚合物 (PVA) 的苯乙烯8和500µg 的20µg 溶解在甲醇的5毫升内。</li>
		<li>在样品上分配3-5 滴 (0.2 毫升) 染料溶液, 并在十年代和 3600 rpm 的 600 rpm 上连续旋转1分钟。厚度估计为 80 nm。 注: 水溶性或不溶性聚合物可作为锚固材料使用, 取决于发射材料的类型。然而, 聚合物应该是非发射的, 这样它就不会干扰光致发光测量。推荐聚乙烯醇聚合物 (PVA) 溶解水溶性染料, 如罗丹明6G 和苯乙烯8。</li>
	</ol>
</li>
</ol>4. 测定细菌衰变率的反射率测量
注意: 偏振和角度分辨反射率光谱学的设置如图 2所示。它包括一个量角器与三个自转阶段为独立地改变样品取向 (阶段 1) 和检测角度 (阶段 2) 并且样品方位角 (阶段 3)。
<ol><li>使用来自石英灯的宽带白光作为光源。首先一对多模光纤束, 然后瞄准它由一对共线面对面物镜 (5X 和 60X)。通过改变样品方向, 在不同入射角度照射样品上的光束。在样品前后放置一对入射偏光片和检测分析仪进行极化依赖性测量。 注: 面对面目标充当透镜系统, collimates 和扩展多模光纤中的白色光源。</li>
	<li>使用多模光纤从样品中收集镜面反射, 连接到光谱仪和用于光谱学的 CCD 探测器。</li>
	<li>仔细对齐设置, 以确保采样方向阶段和检测旋转阶段都是同心的, i. e., 它们的旋转轴是共线的。</li>
	<li>用扁金胶片校准安装。用已知的 Au 介电函数, 测量不同入射角的反射谱, 并与菲涅尔方程计算的理论反射谱进行比较。这两组数据应与不到5% 的错误一致。</li>
	<li>一旦安装就绪, 测量的线性极化, p 或 s, 反射光谱的样品在不同的入射角。入射角的步长为 0.5°, 波长分辨率为 0.66 nm。为了在多个入射角度下采集光谱, 给出了机械运动、快门控制、数据采集、背景减法等自动化控制程序。 注意: 这个步骤是通过计算完成的。该程序可根据要求提供。如有需要, 请向相应的作者发送一封电子邮件给源代码。</li>
	<li>等高线图的反射率与波长和入射角, 以获得等离子系统的色散关系的模式识别和衰减率的确定。 注意: 采样方位角是在布里渊区域中定位位置。例如, 对于方形格子样本, 旋转样品方位, 使其周期之一与入射平面平行, 这就定义了Γ X 方向。通过45°旋转样本来定义Γ M 方向。</li>
	<li>如果在45°上对入射平面设置了入射极化, 并且分析仪位于 45°, 则测量正交或交叉极化反射率映射。</li>
	<li>提取 p 极化和正交反射光谱, 并配合使用9,12,13, 在讨论中所述的许可证的衰变率。</li>
</ol>5. 测定发射功率比的光致发光测量方法
注意: 角度和偏振分辨光致发光设置如图 3所示。
<ol><li>用 514 nm 氩离子或633纳米 HeNe 激光器取代宽带光源。使用一个全宽半最大 (FWHM) 小于 5 nm 的激光线滤波器来清洗激光光谱, 并放置一个半波板来控制激光束的偏振态。量角器和检测单元保持不变。在检测单元前放置一个凹槽过滤器, 以去除激光线, 从而掩埋发光。 注: 激光波长取决于发射材料的类型。更高的光子能量需要激发更短的发射波长的材料。</li>
	<li>测量 Eq 的发射功率比. (2) & (3), 进行两种类型的测量: 检测和事件扫描。事件和检测扫描之间的相互作用有助于<img alt="Equation 10" src="/files/ftp_upload/56735/56735eq10.jpg">确定、 <img alt="Equation 11" src="/files/ftp_upload/56735/56735eq11.jpg"> </img>、 <img alt="Equation 12" src="/files/ftp_upload/56735/56735eq12.jpg">和. <img alt="Equation 13" src="/files/ftp_upload/56735/56735eq13.jpg"> </img></li>
	<li>对于事件扫描, 可连续更改事件角度, 但根据样本的正常情况修正检测角度。 注意: 这个步骤是通过计算完成的。这种配置有选择地激发传入的许可证, 这是入射角度的依赖, 同时监测在所选检测角度下的发射变化。换言之, 当入射角度满足 Eq 中的相位匹配方程时, 发射量增加. (1)。<ol>
<li>轮廓绘制了入射扫描映射的波长和入射角度的光致发光谱。测量不同检测角度的映射, 但发现相对强度相同。因此, 事件扫描探讨了传入许可证对发射的影响或简单的激励增强, 使我们能够测量<img alt="Equation 10" src="/files/ftp_upload/56735/56735eq10.jpg">和. <img alt="Equation 11" src="/files/ftp_upload/56735/56735eq11.jpg"> </img></li>
	</ol>
</li>
	<li>对于检测扫描, 根据样本的正常情况修正入射角度, 但改变检测角度。 注意: 这个步骤是通过计算完成的。<ol>
<li>同样, 轮廓图的光致发光光谱与波长和检测角度产生的检测扫描映射。随着许可证辐射阻尼的产生, 其发射强度与检测角度有关。因此, 在恒定激励下, 当检测角度满足 Eq 时, 发射量增加. (1)。这种配置探讨了发射增强, 并允许我们确定<img alt="Equation 12" src="/files/ftp_upload/56735/56735eq12.jpg">不同α的顺序, 只要它有明确的检测角度依赖性。</li>
	</ol>
</li>
</ol>

<ol>
	<li>Okamoto, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Surface-plasmon-enhanced+light+emitters+based+on+InGaN+quantum+wells.">Surface-plasmon-enhanced light emitters based on InGaN quantum wells.</a> Nature Materials. 3 (9), 601-605 (2004).</li><li>Akselrod, G. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Leveraging+Nanocavity+Harmonics+for+Control+of+Optical+Processes+in+2D+Semiconductors.">Leveraging Nanocavity Harmonics for Control of Optical Processes in 2D Semiconductors.</a> Nano Letters. 15 (5), 3578-3584 (2015).</li><li>Gontijo, I., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Coupling+of+InGaN+quantum-well+photoluminescence+to+silver+surface+plasmons.">Coupling of InGaN quantum-well photoluminescence to silver surface plasmons.</a> Physical Review B. 60 (16), 11564 (1999).</li><li>Huang, K. C. Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Antenna+electrodes+for+controlling+electroluminescence.">Antenna electrodes for controlling electroluminescence.</a> Nature Communications. 3, 1005 (2012).</li><li>Atwater, H. A., Polman, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Plasmonics+for+improved+photovoltaic+devices.">Plasmonics for improved photovoltaic devices.</a> Nature Materials. 9 (3), 205-213 (2010).</li><li>Anker, J. N., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biosensing+with+plasmonic+nanosensors.">Biosensing with plasmonic nanosensors.</a> Nature Materials. 7 (6), 442-453 (2008).</li><li>Chen, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Excitation+enhancement+of+CdSe+quantum+dots+by+single+metal+nanoparticles.">Excitation enhancement of CdSe quantum dots by single metal nanoparticles.</a> Applied Physics Letters. 93 (5), 053106 (2008).</li><li>Birowosuto, M. D., Skipetrov, S. E., Vos, W. L., Mosk, A. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Observation+of+Spatial+Fluctuations+of+the+Local+Density+of+States+in+Random+Photonic+Media.">Observation of Spatial Fluctuations of the Local Density of States in Random Photonic Media.</a> Physical Review Letters. 105 (1), 013904 (2010).</li><li>Cao, Z. L., Ong, H. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Determination+of+coupling+rate+of+light+emitter+to+surface+plasmon+polaritons+supported+on+nanohole+array.">Determination of coupling rate of light emitter to surface plasmon polaritons supported on nanohole array.</a> Applied Physics Letters. 102 (24), 241109 (2013).</li><li>Lin, M., Cao, Z. L., Ong, H. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Determination+of+the+excitation+rate+of+quantum+dots+mediated+by+momentum-resolved+Bloch-like+surface+plasmon+polaritons.">Determination of the excitation rate of quantum dots mediated by momentum-resolved Bloch-like surface plasmon polaritons.</a> Optics Express. 25 (6), 6029-6103 (2017).</li><li>Nikolaev, I. S., Lodahl, P., Driel, A. F. V., Koenderink, A. F., Vos, W. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Strongly+nonexponential+time-resolved+fluorescence+of+quantum-dot+ensembles+in+three-dimensional+photonic+crystals.">Strongly nonexponential time-resolved fluorescence of quantum-dot ensembles in three-dimensional photonic crystals.</a> Physical Review B. 75 (11), 115302 (2007).</li><li>Cao, Z. L., Lo, H. Y., Ong, H. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Determination+of+absorption+and+radiative+decay+rates+of+surface+plasmon+polaritons+from+nanohole+array.">Determination of absorption and radiative decay rates of surface plasmon polaritons from nanohole array.</a> Optics Letters. 37 (24), 5166-5168 (2012).</li><li>Haus, H. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Waves and Fields in Optoelectronics. , (1984).</li></ol>

作者声明他们没有竞争的财政利益。

在本协议中, 有几个关键步骤。首先, 机械稳定性是样品制备的关键。劳埃德设置产生的驻波对两个光照光束的相位差很敏感。因此, 在曝光时间内的任何振动都会降低 nanohole 的均匀性和边缘锐度。强烈建议在无振动环境下操作,例如, 具有隔振支承的光学工作台。此外, 高功率激光器也希望减少振动, 因为它减少曝光时间相应。其次, 必须正确选择步骤1.1 中的针孔。孔的大小应该足够小, 以执...

表面等离子体介导荧光 (SPMF) 最近得到了相当关注1,2,3,4,5,6。当光发射器靠近等离子系统时, 能量可以在发射器和表面等离子极化激元 (许可证) 之间传输。一般情况下, 强等离子场可以强烈增强2发射器的激发。同时, 由于许可证所制造的大密度的状态, 产生了众所周知的珀尔效应3, 排放率也在增加。这两个过程在生产 SPMF 方面携手并进。由于 SPMF 已经在固态照明1、4、能量采集5和生物检测6中激发了大量应用, 目前正在进行密集的调查。特别是, 从许可证到发射器的能量传输速率的知识, 反之亦然,即激发和耦合率, 是非常重要的。然而, 激励和排放过程通常是纠缠在一起的, 这方面的研究还是缺乏的。例如, 大多数研究只确定了激发效率比, 这简单地比较了排放与和不许可证7。激发率的确切的测量仍然是缺掉的。另一方面, 传统的时间分辨技术 (如荧光寿命光谱学) 通常用于研究发射过程的动力学, 但它们无法将耦合率从总衰变率8中分离出来。在这里, 我们描述如何通过结合速率方程模型和时间耦合模式理论9,10来确定它们。值得注意的是, 我们发现, 激发和耦合速率可以用可测量的数量来表示, 这可以通过执行角度和极化分辨反射率和光致发光光谱来获得。我们将首先概述配方, 然后详细描述仪器。这种方法完全是基于频域的, 它不需要任何时间分辨的附件, 如超快激光器和时间相关的单光子计数器, 这是昂贵的, 有时难以实现8,11. 我们预计这项技术将成为确定光发射器和谐振腔之间的励磁和耦合速率的有利技术。
本文介绍了周期性系统中的 SPMF。对于一个周期性的等离子系统, 在这种情况下, 可以产生类似于许可证的直接激发和发射, 其特征是激发效率η和自发发射速率Γr, 发射器可以通过传入的许可证激发并通过传出许可证衰变。换句话说, 在共振激励下, 会产生传入的许可证, 以创建强大的等离子场, 使发射器充满活力。一旦发射器兴奋, 他们的能量就可以转移到传出的许可证, 随后 radiatively 消散到远场, 从而产生增强的排放量。他们定义了 SPMF。对于简单的两能级发射器, 励磁指的是电子从地面向激发态的过渡, 而发射则定义了电子衰变回基态, 伴随着波长定义的光子发射。由兴奋和地面状态之间的能量区别。SPMF 的激发和发射条件, 满足已知的相位匹配方程, 激发传入和传出许可证9
<img alt="Equation 1" src="/files/ftp_upload/56735/56735eq1.jpg">(1)
其中εa和εm是电介质和金属的介电常数, θ和φ是事件和方位角, P 是数组的周期, λ是激发或发射波长, m 和 n 是整数, 指定的顺序许可证.对于励磁, 激光束在平面内的 wavevector 将是布拉格分散到动量匹配的传入许可证和θ和φ一起定义指定的事件配置, 以刺激的许可证, 以提高电子吸收在励磁波长λ前。同样, 对于发射, 传出的许可证将反向布拉格分散, 以匹配的光线, 现在的角度代表可能的发射通道在发射波长λem。然而, 人们注意到, 由于发射器可以将他们的能量耦合到矢量传播<img alt="Equation 2" src="/files/ftp_upload/56735/56735eq2.jpg">许可证与它有相同<img alt="Equation 3" src="/files/ftp_upload/56735/56735eq3.jpg">的大小, 但不同的方向, 许可证可以通过不同的组合 (m, n) 到远场后的 Eq. (1)。
利用速率方程模型和时间耦合模理论 (许可证), 我们发现, 激发率Γex,即能量传递率从从的到发射器, 可以表示为9,12,13
<img alt="Equation 4" src="/files/ftp_upload/56735/56735eq4.jpg">(2)
在没有传入许可证的情况下, η是上述直接励磁速率, γ是许可证<img alt="Equation 5" src="/files/ftp_upload/56735/56735eq5.jpg">的总衰减率, γabs和γrad是许可证的欧姆吸收和辐射衰减率,<img alt="Equation 6" src="/files/ftp_upload/56735/56735eq6.jpg">是具有和没有传入许可证的光致发光功率比。另一方面, 耦合速率Γc(即从发射器到许可证的能量传递速率) 可以写为:
<img alt="Equation 7" src="/files/ftp_upload/56735/56735eq7.jpg">(3)
γr是<img alt="Equation 8" src="/files/ftp_upload/56735/56735eq8.jpg">直接发射速率, 是αth介导衰变与直接端口之间的光致发光功率比, γradα和γ是α端口的辐射衰减率.和总衰变率。我们将看到, 虽然所有的细菌衰变率都可以用反射率光谱学来衡量, 但发射功率比可以通过光致发光光谱学来确定。有关配方的详细资料, 请参阅9、10。

<table><tbody><tr><td>SU-8</td><td>MicroChem</td><td>SU-8 2000.5</td><td></td></tr><tr><td>Adhesion solution</td><td>MicroChem</td><td>Omnicoat</td><td></td></tr><tr><td>SU-8 Thinner (Gamma-Butyrolactone)</td><td>MicroChem</td><td>SU-8 2000 Thinner</td><td></td></tr><tr><td>SU-8 Developer</td><td>MicroChem</td><td>SU-8 Developer</td><td></td></tr><tr><td>Spin Coater</td><td>Chemat Technology</td><td>KW-4A</td><td></td></tr><tr><td>HeCd laser</td><td>KIMMON KOHA CO., LTd</td><td>IK3552R-G</td><td></td></tr><tr><td>Shutter</td><td>Thorlabs</td><td>SH05</td><td></td></tr><tr><td>Objective for sample preparation</td><td>Newport</td><td>U-13X</td><td></td></tr><tr><td>Pinhole</td><td>Newport</td><td>PNH-50</td><td></td></tr><tr><td>Iris</td><td>Newport</td><td>M-DI47.50</td><td></td></tr><tr><td>Prism</td><td>Thorlabs</td><td>PS611</td><td></td></tr><tr><td>Rotation stage for sample preparation</td><td>Newport</td><td>481-A</td><td></td></tr><tr><td>Supttering Deposition System</td><td>Homemade</td><td></td><td></td></tr><tr><td>Rotation Stage 1</td><td>Newport</td><td>URM80ACC</td><td></td></tr><tr><td>Rotation Stage 2</td><td>Newport</td><td>RV120PP</td><td></td></tr><tr><td>Rotation Stage 3</td><td>Newport</td><td>SR50PP</td><td></td></tr><tr><td>Detection arm</td><td>Homemade</td><td></td><td></td></tr><tr><td>Quartz lamp</td><td>Newport</td><td>66884</td><td></td></tr><tr><td>Fiber Bundle</td><td>Newport</td><td>77578</td><td></td></tr><tr><td>Objective for measurement</td><td>Newport</td><td>M-5X &amp;amp; M-60X</td><td></td></tr><tr><td>Polarizer &amp;amp; Analyzer</td><td>Thorlabs</td><td>GT15</td><td></td></tr><tr><td>Multimode Fiber</td><td>Thorlabs</td><td>BFL105LS02</td><td></td></tr><tr><td>Spectrometer</td><td>Newport</td><td>MS260i</td><td></td></tr><tr><td>CCD</td><td>Andor</td><td>DV420-OE</td><td></td></tr><tr><td>514nm Argon Ion Laser</td><td>Spectra-Physics</td><td>177-G01</td><td></td></tr><tr><td>633nm HeNe Laser</td><td>Newport</td><td>R-32413</td><td></td></tr><tr><td>CdSeTe quantum dot</td><td>Thermo Fisher Scientific</td><td>q21061mp</td><td></td></tr><tr><td>Polyvinyl alcohol polymer (PVA)</td><td>SIGMA-ALDRICH</td><td>363073</td><td></td></tr><tr><td>Control program</td><td>National Instruments</td><td>LabVIEW</td><td></td></tr></tbody></table>

determination of the excitation and coupling rates between light emitters and surface plasmon polaritons

我们开发了一种独特的方法来测量光发射器和表面等离子极化激元 (许可证) 产生的金属周期阵列, 而不涉及时间分辨技术的励磁和耦合速率。我们已经制定了数量, 可以用简单的光学测量测量。本文将详细介绍基于角度和偏振分辨反射率和光致发光光谱的仪器。我们的方法是有趣的, 因为它的简单性, 这需要常规光学和几个机械阶段, 因此是高负担得起的大多数研究实验室。

在图 4a8的嵌入中给出了一个 Au 周期阵列的例子。平面观扫描电镜图像表明, 该样品为2D 方形圆孔阵列, 周期为 510 nm, 孔深 280 nm, 孔径为 140 nm。沿Γ X 方向进行的 p 偏振反射率映射如图 4a所示。虚线是由相匹配方程计算的 Eq. (1) 表明 (m =-1, n = 0) 许可证是兴奋的。
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Watch this Scientific Journal Video about Determination of the Excitation and Coupling Rates Between Light Emitters and Surface Plasmon Polaritons at JoVE.com

Determination of the Excitation and Coupling Rates Between Light Emitters and Surface Plasmon Polaritons

本协议描述了用于确定由周期性阵列引起的光发射器和类似于极化激元的表面等离子体的激发和耦合速率的仪器。

光发射器与表面等离子体极化激元的激发和耦合速率的测定

We have developed a unique method to measure the excitation and coupling rates between the light emitters and surface plasmon polaritons (SPPs) arising ...

determination-excitation-coupling-rates-between-light-emitters

Research

JoVE Journal

Engineering

6.7K 次观看.  Sun Yat-sen University. 本协议描述了用于确定由周期性阵列引起的光发射器和类似于极化激元的表面等离子体的激发和耦合速率的仪器。

视频: Determination of the Excitation and Coupling Rates Between Light Emitters and Surface Plasmon Polaritons

Design, Fabrication, and Experimental Characterization of Plasmonic Photoconductive Terahertz Emitters

In this video article we present a detailed demonstration of a highly efficient method for generating terahertz waves. Our technique is based on photoconduction, which has been one of the most commonly used techniques for terahertz generation 1-8. Terahertz generation in a photoconductive emitter is achieved by pumping an ultrafast photoconductor with a pulsed or heterodyned laser illumination. The induced photocurrent, which follows the envelope of the pump laser, is routed to a terahertz radiating antenna connected to the photoconductor contact electrodes to generate terahertz radiation. Although the quantum efficiency of a photoconductive emitter can theoretically reach 100%, the relatively long transport path lengths of photo-generated carriers to the contact electrodes of conventional photoconductors have severely limited their quantum efficiency. Additionally, the carrier screening effect and thermal breakdown strictly limit the maximum output power of conventional photoconductive terahertz sources. To address the quantum efficiency limitations of conventional photoconductive terahertz emitters, we have developed a new photoconductive emitter concept which incorporates a plasmonic contact electrode configuration to offer high quantum-efficiency and ultrafast operation simultaneously. By using nano-scale plasmonic contact electrodes, we significantly reduce the average photo-generated carrier transport path to photoconductor contact electrodes compared to conventional photoconductors 9. Our method also allows increasing photoconductor active area without a considerable increase in the capacitive loading to the antenna, boosting the maximum terahertz radiation power by preventing the carrier screening effect and thermal breakdown at high optical pump powers. By incorporating plasmonic contact electrodes, we demonstrate enhancing the optical-to-terahertz power conversion efficiency of a conventional photoconductive terahertz emitter by a factor of 50 10.

We describe methods for the design, fabrication, and experimental characterization of plasmonic photoconductive emitters, which offer two orders of magnitude higher terahertz power levels compared to conventional photoconductive emitters.

电浆光电导太赫兹发射器的设计，制造和实验表征

In this video article we present a detailed demonstration of a highly efficient method for generating terahertz waves. Our technique is based on ...

科研

工程学

Evaluating Plasmonic Transport in Current-carrying Silver Nanowires

Plasmonics is an emerging technology capable of simultaneously transporting a plasmonic signal and an electronic signal on the same information support1,2,3. In this context, metal nanowires are especially desirable for realizing dense routing networks4. A prerequisite to operate such shared nanowire-based platform relies on our ability to electrically contact individual metal nanowires and efficiently excite surface plasmon polaritons5 in this information support. In this article, we describe a protocol to bring electrical terminals to chemically-synthesized silver nanowires6 randomly distributed on a glass substrate7. The positions of the nanowire ends with respect to predefined landmarks are precisely located using standard optical transmission microscopy before encapsulation in an electron-sensitive resist. Trenches representing the electrode layout are subsequently designed by electron-beam lithography. Metal electrodes are then fabricated by thermally evaporating a Cr/Au layer followed by a chemical lift-off. The contacted silver nanowires are finally transferred to a leakage radiation microscope for surface plasmon excitation and characterization8,9. Surface plasmons are launched in the nanowires by focusing a near infrared laser beam on a diffraction-limited spot overlapping one nanowire extremity5,9. For sufficiently large nanowires, the surface plasmon mode leaks into the glass substrate9,10. This leakage radiation is readily detected, imaged, and analyzed in the different conjugate planes in leakage radiation microscopy9,11. The electrical terminals do not affect the plasmon propagation. However, a current-induced morphological deterioration of the nanowire drastically degrades the flow of surface plasmons. The combination of surface plasmon leakage radiation microscopy with a simultaneous analysis of the nanowire electrical transport characteristics reveals the intrinsic limitations of such plasmonic circuitry.

Silver nanowires can simultaneously transport electrons and optical information in the form of surface plasmons. A procedure is described here to realize such a shared circuitry and the limitations at propagating both information carriers are evaluated.

Plasmonics is an emerging technology capable of simultaneously transporting a plasmonic signal and an electronic signal on the same information ...

Synthesis, Characterization, and Functionalization of Hybrid Au/CdS and Au/ZnS Core/Shell Nanoparticles

Plasmonic nanoparticles are an attractive material for light harvesting applications due to their easily modified surface, high surface area and large extinction coefficients which can be tuned across the visible spectrum. Research into the plasmonic enhancement of optical transitions has become popular, due to the possibility of altering and in some cases improving photo-absorption or emission properties of nearby chromophores such as molecular dyes or quantum dots. The electric field of the plasmon can couple with the excitation dipole of a chromophore, perturbing the electronic states involved in the transition and leading to increased absorption and emission rates. These enhancements can also be negated at close distances by energy transfer mechanism, making the spatial arrangement of the two species critical. Ultimately, enhancement of light harvesting efficiency in plasmonic solar cells could lead to thinner and, therefore, lower cost devices. The development of hybrid core/shell particles could offer a solution to this issue. The addition of a dielectric spacer between a gold nanoparticles and a chromophore is the proposed method to control the exciton plasmon coupling strength and thereby balance losses with the plasmonic gains. A detailed procedure for the coating of gold nanoparticles with CdS and ZnS semiconductor shells is presented. The nanoparticles show high uniformity with size control in both the core gold particles and shell species allowing for a more accurate investigation into the plasmonic enhancement of external chromophores.

The synthesis of uniform gold nanoparticles coated with semiconductor shells of CdS or ZnS is performed. The semiconductor coating is conducted by first depositing a silver sulfide shell and exchanging the silver cations for zinc or cadmium cations.

合成，表征和混合金/硫化镉和Au / ZnS核/壳纳米颗粒功能化

Plasmonic nanoparticles are an attractive material for light harvesting applications due to their easily modified surface, high surface area and large ...

化学

Measurement of Scattering Nonlinearities from a Single Plasmonic Nanoparticle

Plasmonics, which are based on the collective oscillation of electrons due to light excitation, involve strongly enhanced local electric fields and thus have potential applications in nonlinear optics, which requires extraordinary optical intensity. One of the most studied nonlinearities in plasmonics is nonlinear absorption, including saturation and reverse saturation behaviors. Although scattering and absorption in nanoparticles are closely correlated by the Mie theory, there has been no report of nonlinearities in plasmonic scattering until very recently. 
Last year, not only saturation, but also reverse saturation of scattering in an isolated plasmonic particle was demonstrated for the first time. The results showed that saturable scattering exhibits clear wavelength dependence, which seems to be directly linked to the localized surface plasmon resonance (LSPR). Combined with the intensity-dependent measurements, the results suggest the possibility of a common mechanism underlying the nonlinear behaviors of scattering and absorption. These nonlinearities of scattering from a single gold nanosphere (GNS) are widely applicable, including in super-resolution microscopy and optical switches. 
In this paper, it is described in detail how to measure nonlinearity of scattering in a single GNP and how to employ the super-resolution technique to enhance the optical imaging resolution based on saturable scattering. This discovery features the first super-resolution microscopy based on nonlinear scattering, which is a novel non-bleaching contrast method that can achieve a resolution as low as l/8 and will potentially be useful in biomedicine and material studies.

Saturable and reverse saturable scattering were discovered in isolated plasmonic particles and adopted as a novel non-bleaching contrast method in super-resolution microscopy. Here the experimental procedures of detecting and extracting nonlinear scattering are explained in detail, as well as how to enhance resolution with the aid of saturated excitation microscopy.

从单电浆纳米粒子散射非线性测量

Plasmonics, which are based on the collective oscillation of electrons due to light excitation, involve strongly enhanced local electric fields and thus ...

Colloidal Synthesis of Nanopatch Antennas for Applications in Plasmonics and Nanophotonics

We present a method for colloidal synthesis of silver nanocubes and the use of these in combination with a smooth gold film, to fabricate plasmonic nanoscale patch antennas. This includes a detailed procedure for the fabrication of thin films with a well-controlled thickness over macroscopic areas using layer-by-layer deposition of polyelectrolyte polymers, namely poly(allylamine) hydrochloride (PAH) and polystyrene sulfonate (PSS). These polyelectrolyte spacer layers serve as a dielectric gap in between silver nanocubes and a gold film. By controlling the size of the nanocubes or the gap thickness, the plasmon resonance can be tuned from about 500 nm to 700 nm. Next, we demonstrate how to incorporate organic sulfo-cyanine5 carboxylic acid (Cy5) dye molecules into the dielectric polymer gap region of the nanopatch antennas. Finally, we show greatly enhanced fluorescence of the Cy5 dyes by spectrally matching the plasmon resonance with the excitation energy and the Cy5 absorption peak. The method presented here enables the fabrication of plasmonic nanopatch antennas with well-controlled dimensions utilizing colloidal synthesis and a layer-by-layer dip-coating process with the potential for low cost and large-scale production. These nanopatch antennas hold great promise for practical applications, for example in sensing, ultrafast optoelectronic devices and for high-efficiency photodetectors.

A protocol for the colloidal synthesis of silver nanocubes and fabrication of plasmonic nanoscale patch antennas with sub-10 nm gaps is presented.

在等离子体激元和纳米光子学应用Nanopatch天线的合成胶体

We present a method for colloidal synthesis of silver nanocubes and the use of these in combination with a smooth gold film, to fabricate plasmonic ...

Measurement of Quantum Interference in a Silicon Ring Resonator Photon Source

Silicon photonic chips have the potential to realize complex integrated quantum information processing circuits, including photon sources, qubit manipulation, and integrated single-photon detectors. Here, we present the key aspects of preparing and testing a silicon photonic quantum chip with an integrated photon source and two-photon interferometer. The most important aspect of an integrated quantum circuit is minimizing loss so that all of the generated photons are detected with the highest possible fidelity. Here, we describe how to perform low-loss edge coupling by using an ultra-high numerical aperture fiber to closely match the mode of the silicon waveguides. By using an optimized fusion splicing recipe, the UHNA fiber is seamlessly interfaced with a standard single-mode fiber. This low-loss coupling allows the measurement of high-fidelity photon production in an integrated silicon ring resonator and the subsequent two-photon interference of the produced photons in a closely integrated Mach-Zehnder interferometer. This paper describes the essential procedures for the preparation and characterization of high-performance and scalable silicon quantum photonic circuits.

Silicon photonic chips have the potential to realize complex integrated quantum systems. Presented here is a method for preparing and testing a silicon photonic chip for quantum measurements.

量子干涉效应在硅谐振环光子源测量

Silicon photonic chips have the potential to realize complex integrated quantum information processing circuits, including photon sources, qubit ...

Performing Spectroscopy on Plasmonic Nanoparticles with Transmission-Based Nomarski-Type Differential Interference Contrast Microscopy

Differential interference contrast (DIC) microscopy is a powerful imaging tool that is most commonly employed for imaging microscale objects using visible-range light. The purpose of this protocol is to detail a proven method for preparing plasmonic nanoparticle samples and performing single particle spectroscopy on them with DIC microscopy. Several important steps must be followed carefully in order to perform repeatable spectroscopy experiments. First, landmarks can be etched into the sample substrate, which aids in locating the sample surface and in tracking the region of interest during experiments. Next, the substrate must be properly cleaned of debris and contaminants that can otherwise hinder or obscure examination of the sample. Once a sample is properly prepared, the optical path of the microscope must be aligned, using Kohler Illumination. With a standard Nomarski style DIC microscope, rotation of the sample may be necessary, particularly when the plasmonic nanoparticles exhibit orientation-dependent optical properties. Because DIC microscopy has two inherent orthogonal polarization fields, the wavelength-dependent DIC contrast pattern reveals the orientation of rod-shaped plasmonic nanoparticles. Finally, data acquisition and data analyses must be carefully performed. It is common to represent DIC-based spectroscopy data as a contrast value, but it is also possible to present it as intensity data. In this demonstration of DIC for single particle spectroscopy, the focus is on spherical and rod-shaped gold nanoparticles.

The goal of this protocol is to detail a proven approach for the preparation of plasmonic nanoparticle samples and for performing single particle spectroscopy on them with differential interference contrast (DIC) microscopy.

基于传输的野武学型差分干涉对比显微镜对等离子体纳米粒子的光谱处理

Differential interference contrast (DIC) microscopy is a powerful imaging tool that is most commonly employed for imaging microscale objects using ...

Spectral and Angle-Resolved Magneto-Optical Characterization of Photonic Nanostructures

Photonic crystals are periodic nanostructures that can support a variety of confined electromagnetic modes. Such confined modes are usually accompanied by local enhancement of electric field intensity that strengthens light-matter interactions, enabling applications such as surface-enhanced Raman scattering (SERS) and surface plasmon enhanced sensing. In the presence of magneto-optically active materials, the local field enhancement gives rise to anomalous magneto-optical activity. Typically, the confined modes of a given photonic crystal depend strongly on the wavelength and incidence angle of the incident electromagnetic radiation. Thus, spectral and angular-resolved measurements are needed to fully identify them as well as to establish their relationship with the magneto-optical activity of the crystal. In this article, we describe how to use a Fourier-plane (back focal plane) microscope to characterize magneto-optically active samples. As a model system, here we use a plasmonic grating built out of magneto-optically active Au/Co/Au multilayer. In the experiments, we apply a magnetic field on the grating in situ and measure its reciprocal space response, obtaining the magneto-optical response of the grating over a range of wavelengths and incident angles. This information enables us to build a complete map of the plasmonic band structure of the grating and the angle and wavelength dependent magneto-optical activity. These two images allow us to pinpoint the effect that the plasmon resonances have on the magneto-optical response of the grating. The relatively small magnitude of magneto-optical effects requires a careful treatment of the acquired optical signals. To this end, an image processing protocol for obtaining magneto-optical response from the acquired raw data is laid out.

Photonic band structure enables understanding how confined electromagnetic modes propagate within a photonic crystal. In photonic crystals that incorporate magnetic elements, such confined and resonant optical modes are accompanied by enhanced and modified magneto-optical activity. We describe a measurement procedure to extract the magneto-optical band structure by Fourier space microscopy.

光子纳米结构的光谱和角度解析磁-光学特性

Photonic crystals are periodic nanostructures that can support a variety of confined electromagnetic modes. Such confined modes are usually accompanied by ...

Optical Trapping of Plasmonic Nanoparticles for In Situ Surface-Enhanced Raman Spectroscopy Characterizations

Surface-enhanced Raman spectroscopy (SERS) enables the ultrasensitive detection of analyte molecules in various applications due to the enhanced electric field of metallic nanostructures. Salt-induced silver nanoparticle aggregation is the most popular method for generating SERS-active substrates; however, it is limited by poor reproducibility, stability, and biocompatibility. The present protocol integrates optical manipulation and SERS detection to develop an efficient analytical platform to address this. A 1064 nm trapping laser and a 532 nm Raman probe laser are combined in a microscope to assemble silver nanoparticles, which generate plasmonic hotspots for in situ SERS measurements in aqueous environments. Without aggregating agents, this dynamic plasmonic silver nanoparticle assembly enables an approximately 50-fold enhancement of the analyte molecule signal. Moreover, it provides spatial and temporal control to form the SERS-active assembly in as low as 0.05 nM analyte-coated silver nanoparticle solution, which minimizes the potential perturbation for in vivo analysis. Hence, this optical trapping-integrated SERS platform holds great potential for efficient, reproducible, and stable molecular analyses in liquids, especially in aqueous physiological environments.

Optical Trapping of Plasmonic Nanoparticles for In Situ Surface-Enhanced Raman Spectroscopy Characterizations

The present protocol describes a convenient approach to integrating optical trapping and surface-enhanced Raman spectroscopy (SERS) to manipulate plasmonic nanoparticles for sensitive molecular detection. Without aggregating agents, the trapping laser assembles plasmonic nanoparticles to enhance the SERS signals of target analytes for in situ spectroscopic measurements.

等离子体纳米颗粒的光学捕获用于 原位 表面增强拉曼光谱表征

Surface-enhanced Raman spectroscopy (SERS) enables the ultrasensitive detection of analyte molecules in various applications due to the enhanced electric ...

生物工程

Localized Surface Plasmon Resonance Imaging to Detect Protein Secretions from a Single Cell

Source: Raghu, D. et al., <a href="https://app.jove.com/v/53120">A Label-free Technique for the Spatio-temporal Imaging of Single Cell Secretions.</a> J. Vis. Exp.&#160;(2015)
This video demonstrates localized surface plasmon resonance imaging to detect protein secretions from a single cell. Using a microfluidic setup and a peptide-bound plasmonic nanostructure chip, changes in reflected light intensity at the resonance angle reveal interactions with secreted proteins from a single cell.

光发射器与表面等离子体极化激元的激发和耦合速率的测定

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此视频中的章节

电浆光电导太赫兹发射器的设计，制造和实验表征

Evaluating Plasmonic Transport in Current-carrying Silver Nanowires

合成，表征和混合金/硫化镉和Au / ZnS核/壳纳米颗粒功能化

从单电浆纳米粒子散射非线性测量

在等离子体激元和纳米光子学应用Nanopatch天线的合成胶体

量子干涉效应在硅谐振环光子源测量

基于传输的野武学型差分干涉对比显微镜对等离子体纳米粒子的光谱处理

光子纳米结构的光谱和角度解析磁-光学特性

等离子体纳米颗粒的光学捕获用于原位表面增强拉曼光谱表征

用于检测单个细胞中蛋白质分泌物的局部表面等离子体共振成像

光发射器与表面等离子体极化激元的激发和耦合速率的测定

摘要

探索更多视频

此视频中的章节

电浆光电导太赫兹发射器的设计，制造和实验表征

Evaluating Plasmonic Transport in Current-carrying Silver Nanowires

合成，表征和混合金/硫化镉和Au / ZnS核/壳纳米颗粒功能化

从单电浆纳米粒子散射非线性测量

在等离子体激元和纳米光子学应用Nanopatch天线的合成胶体

量子干涉效应在硅谐振环光子源测量

基于传输的野武学型差分干涉对比显微镜对等离子体纳米粒子的光谱处理

光子纳米结构的光谱和角度解析磁-光学特性

等离子体纳米颗粒的光学捕获用于 原位 表面增强拉曼光谱表征

用于检测单个细胞中蛋白质分泌物的局部表面等离子体共振成像

等离子体纳米颗粒的光学捕获用于原位表面增强拉曼光谱表征