这里介绍的工作是在FFG资助的项目“绿色传感”和北约SPS计划“用于检测CBRN事件的光子纳米粒子传感器”的框架内进行的。这项工作还得到了格拉茨工业大学开放获取出版基金的支持。

1. 测量单元的三维打印
<ol><li>使测量单元（ 如补充编码文件 1 中所述）适应您的应用。三维打印电池和盖子，在 补充编码文件 1-3 中给出，用于安装块状光学材料。 注意：本研究使用了SLA 3D打印机（见 材料表）。</li>
	<li>生成打印作业时，请确保尽量减少空腔和开口内的支撑结构数量。残留的树脂会减小直径，并且块状光学元件可能会卡住。</li>
	<li>打印后，用异丙醇清洁电池，并用线切割机和砂纸去除所有支撑结构。</li>
	<li>在打印后和固化前立即穿上适当的孔。<ol><li>将气体入口和出口穿成 M5 以安装软管连接器。</li>
		<li>将底部的中心孔作为 M4 穿线，用于电池的后安装。</li>
		<li>将较小的通孔垂直于笼杆通孔中，如M3，以允许将电池固定到笼系统上（图2）。</li>
	</ol></li>
	<li>使用市售的UV固化装置在60°C下对细胞（405nm）和盖子进行UV固化至少40分钟（参见 材料表）。</li>
</ol><img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/65174/65174fig02.jpg"> 图 2：测量单元的标记 CAD 模型渲染。 为了更清楚起见，此处提供了剖面图。 <a href="https://jove.unicartagenaproxy.elogim.com/files/ftp_upload/65174/65174fig02large.jpg" target="_blank">请点击此处查看此图的大图。</a>
2. 准备垫片
<ol><li>从一个紫外熔融石英 （UVFS） 精密窗口中切出两个垫片。从精密窗口中切出两块大约 3 mm 宽的碎片，如图 3B 所示。 注意： 垫片可以使用传统的低成本玻璃切割机切割（见 材料表）。 注意：切割和处理散装光学器件时戴上手套和防护眼镜。</li>
	<li>用切割工具在精密窗口上划一条直线，然后用钳子打碎玻璃。始终使用表面平坦的钳子，并在金属和玻璃之间放置镜片清洁纸巾（或类似纸巾），以防止损坏玻璃表面。</li>
	<li>用喷雾剂清洁垫片，以清除残留的玻璃碎屑。 注意：此外，垫片可以用镜片清洁液和镜片清洁纸巾仔细擦拭，而无需施加压力。</li>
</ol>3. 标准具的组装
<ol><li>将3D打印的细胞（步骤1）放在桌子上，标准具坑朝上。</li>
	<li>将 O 形圈（10 mm x 1 mm，见 材料表）插入标准具凹坑，然后将其轻轻压入指定的凹槽中。</li>
	<li>将反射面朝上放置在标准具凹坑中并放在 O 形圈上。</li>
	<li>使用镊子小心地将两个垫片放在分光镜上。将它们放置在为气体和激发激光器产生清晰孔径的方式，气体和激发激光器通过从电池一侧到另一侧的通孔 进入 气腔（图2，数字3）。 注意：垫片必须放置在每侧以获得中间的气腔，如图 3B所示。仅抓住侧面上的垫片，以免划伤平行表面。</li>
	<li>当垫片就位时，将镜子对准它们顶部，反射面朝下。分光镜、垫片和反射镜现在必须同心对齐。</li>
	<li>取下3D打印的标准具帽，将两个O形圈（10 mm x 1 mm和14 mm x 2 mm）放入指定的凹槽中。</li>
	<li>将盖子对准单元格的矩形凹槽，并将其放在镜子的顶部。<ol><li>对盖子施加压力以将垫片固定到位。提起电池，同时始终对盖子施加压力，并从背面将四个 M4 螺钉插入指定的孔中。</li>
		<li>在正面安装四个 M4 螺母，然后拧紧它们，直到盖子的压力足以将垫片固定到位并且 O 形圈被压缩到位。</li>
		<li>检查垫片是否仍在原位;如果是这样，标准具现在可以进一步使用了。</li>
	</ol></li>
	<li>使用两个额外的3D打印盖将激光窗口安装在测量池的侧面，以使测量池气密。因此，将一个 O 形圈 （10 mm x 1 mm） 放入电池上的指定凹槽中，将另一个 O 形圈 （10 mm x 1 mm） 放在盖子上。将窗口放在凹槽中，并用四个 M3 螺钉和螺母固定窗盖，如图 2 号所示。</li>
</ol><img alt="Figure 3" class="xfigimg" src="/files/ftp_upload/65174/65174fig03.jpg"> 图 3：测量单元和 FPE 的渲染。 （A） 3D 打印单元以及带有相应安装帽的 FPE 的组装过程渲染。（B） 按正确的顺序呈现大块光学组件。垫片在两个镜面之间形成一个空气间隔的空腔。<a href="https://jove.unicartagenaproxy.elogim.com/files/ftp_upload/65174/65174fig03large.jpg" target="_blank">请点击此处查看此图的大图。</a>
4. 光纤对准平台的组装
<ol><li>按照 材料表中列出的顺序和转接板进行组装。在施工过程中使用 图 4 作为方向。</li>
	<li>将第一个单轴测角平台安装在光学试验板上的x方向上。 注意：轴命名法是任意选择的。光学试验板平面定义为 x-y 平面，垂直方向朝向试验板外，方向为正 z 方向。</li>
	<li>如有必要，根据所使用的载物台，在测角载物台的顶部安装转接板。<ol><li>在转接板顶部中央安装一个双轴x-y千分尺平移平台。</li>
		<li>将直角支架安装到面向 y 方向的平移台上。</li>
		<li>将单轴平移载物台安装在 z 方向的直角支架上。</li>
	</ol></li>
	<li>使用额外的转接板，将第二个测角平台沿 z 方向安装在平移平台上。</li>
	<li>将光纤套圈夹固定在柱子顶部。选择立柱的长度，使光纤套圈正好位于第二个垂直测角阶段的旋转点。距离在舞台的手册中给出。</li>
	<li>光纤套圈的外径为 2.8 毫米。如果没有此直径的夹具可用，请使用 2.5 mm 夹具，并用钻头将其加宽。</li>
	<li>将带有套圈夹的柱子安装在第二个垂直测角载物台上的z位置，对应于步骤4.2中第一个水平测角载物台的旋转点。<ol><li>确保套圈套筒和 GRIN 透镜在负 z 方向上从套圈夹中伸出几毫米。</li>
		<li>选择立柱的垂直位置，使GRIN透镜的尖端位于测角阶段的旋转点。</li>
	</ol></li>
	<li>要安装标准具，请取一个柱子，在其上安装直角支架，并在其上安装标准 SM1 螺纹 30 mm 笼板。将四根笼杆 （>40 mm） 安装在面向正 z 方向的板上。</li>
	<li>取四个内径略大于笼杆直径的金属弹簧，并在每个笼杆上放置一个。将带有集成FPE的测量单元滑到杆上，分光镜侧朝上，直到它放在弹簧上。 注意：确保单元格可以在 z 方向上自由移动。如果摩擦力太高，则需要为笼杆额外加宽电池的通孔。这最好使用圆形文件来完成。</li>
	<li>通过立柱支架、底板和夹叉 将 立柱安装在光纤对准平台下方。确保露出分光镜的单元开口位于套圈支架下方约 10 mm 的中心（步骤 4.5）。</li>
</ol><img alt="Figure 4" class="xfigimg" src="/files/ftp_upload/65174/65174fig04.jpg"> 图 4：紫外光固化过程中使用 GRIN 透镜耦合的 FPE 的对准平台图片。 以灰色书写的组件用于 PTI 测量，对于对齐过程不是必需的。 <a href="https://jove.unicartagenaproxy.elogim.com/files/ftp_upload/65174/65174fig04large.jpg" target="_blank">请点击此处查看此图的大图。</a>
5. 光电设置
<ol><li>组装 材料表中列出的光电元件，并如图 5所示进行示意图排列。</li>
	<li>使用相应的组件托盘将光纤组件安装在光学试验板上。</li>
	<li>将激光器安装在半导体激光管支架上。将激光源连接到具有集成调制功能（三角调制）的激光驱动器和TEC（热电冷却器）控制器;否则，需要额外的函数发生器。</li>
	<li>设置三角电流调制幅度的方式应覆盖远高于标准具的预期FWHM的波长范围（计算可以在讨论部分找到）。将调制频率设置为 100 Hz 左右。</li>
	<li>使用 L 型支架配接套管将激光器的光输出连接到隔离器输入。</li>
	<li>在隔离器之后安装一个15 dB光纤衰减器，并将其连接到1 x 2耦合器的输入端口。</li>
	<li>将耦合器的输出端口以 90% 光功率连接到光环行器的端口 1。</li>
	<li>将耦合器的输出端口以10%的光功率连接到平衡检波器的参考光电二极管。</li>
	<li>将环行器的端口 2 连接到尾纤套圈-GRIN 透镜系统。</li>
	<li>将端口 3 连接到检测器的信号光电二极管。</li>
	<li>将平衡检测器设置为“自动平衡”模式。使用 BNC 电缆将检测器的电“信号”输出连接到示波器的一个通道。</li>
</ol><img alt="Figure 5" class="xfigimg" src="/files/ftp_upload/65174/65174fig05.jpg"> 图 5：对准程序的光电设置示意图。 红线代表光纤，黑线是电子电缆，蓝色光束是探针激光器。这里使用平衡探测器，但可以用传统的光电探测器代替。因此，可以省略1 x 2耦合器。 <a href="https://jove.unicartagenaproxy.elogim.com/files/ftp_upload/65174/65174fig05large.jpg" target="_blank">请点击此处查看此图的大图。</a>
6. 纤维-GRIN 镜片对准
<ol><li>将套圈夹安装在立柱上，并通过立柱支架 将其 固定到光学试验板上。</li>
	<li>将光纤套圈固定到套圈夹中。如步骤 4.6 中所述，如有必要，用钻头加宽套圈夹。</li>
	<li>用紫外线固化粘合剂填充移液器（见 材料表）。 注意：在处理散装光学器件以及紫外线固化粘合剂时，请戴上手套和眼镜。</li>
	<li>取尾纤纤维套圈，在套圈的侧面加入一滴粘合剂。保持套圈前表面清洁。</li>
	<li>将套圈插入套圈套。确保将套圈插入足够深，使 GRIN 透镜的前端至少在套圈套外 1-2 mm。</li>
	<li>用紫外线灯（~10秒）进行非常快速的预固化。仅从背面（套圈的光纤端）照射光线以将套圈固定到套筒上，而不会硬化套圈前端的任何粘合剂。</li>
	<li>拿起GRIN镜头，找到楔形的一面。这可以用显微镜或简单地转动它来完成。因此，8°楔形面变得可见。</li>
	<li>将滴胶粘剂涂在GRIN镜片的楔形端，然后将其插入套圈套管中。 注意： 通过施加轻微的压力，空气离开套圈和GRIN镜片之间的空腔。两个表面之间可能没有气泡。如果有，轻微的转弯会有所帮助;否则，取下 GRIN 镜头，然后重复步骤 6.8。</li>
	<li>小心旋转GRIN镜头，直到两个倾斜的表面平行。</li>
	<li>在GRIN透镜前方约150 mm处安装光束分析仪。如果没有可用的光束分析仪，则可以使用前面带有针孔的功率计。</li>
	<li>将尾纤套圈连接到具有适当波长的激光器。打开激光。 注意：必须采取激光安全预防措施。</li>
	<li>使用镊子，将 GRIN 透镜从套筒中稍微移出，以更改套圈和 GRIN 透镜之间的距离。此距离对于设置系统的焦距至关重要。移动GRIN透镜时，持续监测光束形状（或光功率）。 注意：如果对准过程太不稳定，短暂的预固化（~10 s）会有所帮助。</li>
	<li>当系统聚焦到所需的最佳状态时，将其暴露在紫外线下约10分钟，以应用最终固化。</li>
	<li>固化后，从夹子上取下套圈套;此时，它已准备好进一步使用。</li>
</ol>7. 纤维-标准具对准
<ol><li>从步骤 5 中取出尾纤套圈和 GRIN 透镜系统，并使用步骤 4.5 中的套圈夹将其安装。</li>
	<li>确保 z 方向上的平移阶段移动到其最大高度，并且所有其他阶段都处于中性（居中）位置。</li>
	<li>对齐其下方的单元格。确保GRIN镜片直接指向开口的中心。将细胞的位置固定在略低于GRIN镜头的高度（约5毫米）。</li>
	<li>用移液器在GRIN镜头的前端涂上一到两滴粘合剂。</li>
	<li>在z方向上降低平移台，直到确保与分光镜的增透涂层表面接触。继续降低GRIN镜片，直到施加足够的压力并且弹簧处于足够的张力下。 注意： 这可确保在对准的倾斜过程中保持GRIN透镜和分光镜之间的接触。所需的压力量取决于设置，如果无法观察到合理的反射函数，则可以在对准期间进行调整。经验表明，更大的压力通常有助于对齐过程。</li>
	<li>打开调制激光和示波器。确保示波器在开始对准过程时具有尽可能高的分辨率 <img alt="Equation 7" src="/files/ftp_upload/65174/65174eq07.jpg" style="margin: auto;">。设置时间分辨率，使两到三个调制周期可见。</li>
	<li>通过确保GRIN透镜正常指向分光镜表面来开始对准过程。这可以通过目视检查并相应地转动测角平台来完成。现在是零位置。</li>
	<li>一步一步地，稍微偏转一个测角载物台，然后将另一个测角载物台移动到零位置。<ol><li>如果在示波器上看不到变化，请稍微偏转第一个测角级，并重复此迭代过程，直到三角调制在示波器上可见。</li>
		<li>如果在载物台移动后观察到信号滞后，请检查所有组件是否正确固定。 注意：向下移动z级引起的压力增加也有帮助。如果观察到的信号不如预期强，则背反射可能来自标准具的一个表面或反射率函数的外围峰值之一。根据经验，使用70%的分光镜和全反射镜，观察到的峰值反射约为引入标准具的光功率的25%。</li>
	</ol></li>
	<li>一旦观察到强烈的背反射，调整示波器的分辨率，并确保标准具反射函数的峰值位于三角调制斜率的中心（图 6）。通过改变激光的温度来调整标准具的峰值，直到峰值以斜率为中心。</li>
	<li>尝试最大化峰值强度（最小电压），同时通过测角级的轻微移动来最大化三角调制的峰峰值比。</li>
	<li>对准过程完成后，将紫外灯安装在GRIN透镜附近。使用成 45° 角的自定心镜头卡口。</li>
	<li>逐步进行固化。首先，固化步骤7.4中已经应用的粘合剂。继续监控示波器上的反射率功能。如果固化导致由于粘合剂收缩而导致取向退化，请稍微调整测角阶段。</li>
	<li>5-10分钟后，关闭紫外灯，并在GRIN镜片周围涂上更多的粘合剂，不要触摸它。将粘合剂暴露在紫外线下再暴露5-10分钟。重复此步骤，直到细胞的开口完全充满均匀的粘合剂层。进行最终固化超过1小时。</li>
	<li>为确保胶合组件的正确连接，如果可能，让整个设置休息1周或在60°C下回火粘合接头1小时。</li>
	<li>现在，套圈套可以从夹具上取下。因此，沿正 z 方向移动平移阶段，直到弹簧完全松弛。避免对套圈-GRIN镜片系统施加任何压力;打开夹子，然后将其取下。现在，标准具已经完成并准备进一步使用。</li>
</ol><img alt="Figure 6" class="xfigimg" src="/files/ftp_upload/65174/65174fig06.jpg"> 图 6：示例性通用示波器信号。 绿色表示良好的对齐方式，黄色表示较差的对齐方式。对齐越好，三角调制的峰峰值比越高，反射率峰值（谷值）越接近零。 <a href="https://jove.unicartagenaproxy.elogim.com/files/ftp_upload/65174/65174fig06large.jpg" target="_blank">请点击此处查看此图的大图。</a>
8. 标准具表征
<ol><li>要评估生产的标准具，请使用与步骤 5 中所述相同的光纤设置。使用能够逐步调整激光器温度并具有足够数据记录速率的测量系统。 注意：此处使用的是基于 FPGA 的系统（参见 材料表）。</li>
	<li>计算理论 FSR。根据所使用的激光器（参见温度调谐系数），执行对应于至少两个FSR的温度扫描。 逐步增加温度（增量~0.005°C），让TEC稳定2-3秒，然后每次再测量2-3秒。</li>
	<li>使用任何数值计算程序处理数据。使用任何带有集成峰值查找器的信号处理库。两个后续峰值之间的距离表示FSR。通过评估峰的半高宽度来计算FWHM。 注意：由于FSR和FWHM的计算在很大程度上取决于数据格式，因此此处没有给出代码，但作者可以根据要求提供代码。</li>
	<li>使用激光器的温度调谐系数将温度转换为波长。</li>
	<li>根据测量值计算FSR和FWHM（图7）。</li>
	<li>使用以下公式计算制造的 FPE 的精细度： <img alt="Equation 8" src="/files/ftp_upload/65174/65174eq08.jpg" style="margin: auto;">.</li>
</ol>

法布里-珀罗标准具的制备在痕量气体光谱中的应用

<ol>
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不存在利益冲突。

由于按照此处给出的协议制造的FPE针对特定应用进行了优化，因此本章解释了可能的调整和关键步骤。首先，FPE和测量单元是为PTI测量而设计的。因此，在电池中增加了气体入口和出口以及垂直于探针激光器的激发激光器通道。电池的所有开口要么 通过 O形圈进行气密处理，要么 通过UVFS 窗口覆盖，以允许激光传播。如果使用方式不同，则可以重新设计电池（ 如补充编码文件1中所示）并适应特定应用。步骤 1.4 中的线程在打印后完成。螺纹也可以是3D打印的，但由于这些螺纹往往会快速磨损，因此只打印具有适当芯孔直径的孔，然后进行螺纹加工。
步骤2.1中间隔条的材料选择至关重要。垫片的平行度决定了标准罩镜的平行度，因此会影响技巧7。本研究使用了材料表中提供的 1/2 英寸 UVFS 精密窗口，平行度为 ≤5 弧秒，在通光孔径上的表面平整度为 λ/10。UVFS的热膨胀系数为0.55 x 10−6/°C。 例如，通过使用热膨胀系数低于0.1 x 10−6/°C的Zerodur5间隔条，可以进一步提高温度稳定性;但是，这样做的缺点是成本较高。
FPE由一个全反射镜和一个分光镜组成。分光镜有一个70%的反射面，以及一个防反射涂层的背面。这使得光进出标准具的耦合成为可能。此外，分光镜的基板具有一个楔形面，以防止不必要的标准具效应。出于同样的原因，镜子的背面被粗糙。
在步骤5.1中，描述了用于跟踪对准过程的光电设置。所有使用的光纤都是带有FC / APC连接器的标准SMF-28光纤。由于PTI的指定应用，本研究中很容易获得平衡光电探测器，但这通常不是必需的。可以使用传统的光电探测器代替;在这种情况下，使用 1 x 2 耦合器已经过时。这些更改不会影响设置的其他组件，如图 5 所示。如步骤5.4所述，探针激光器的三角电流调制对应于波长扫描。必须选择足以扫描FPE的至少一个反射率峰值的电流范围。因此，一个 FSR 可以作为经验法则。理想FPE的FSR计算可以在介绍部分找到。结合相应手册中给出的激光器的电流调谐系数（nm/mA），可以计算出覆盖一个FSR的电流范围。例如，这项工作中使用的激光器的电流调谐系数为0.003 nm / mA，发射波长为1，550 nm。具有 3 mm 镜间距 d 的理想 FPE 的预期 FSR 约为 0.4 nm。这提供了133 mA的电流调谐范围。
在这项工作中，调制频率设置为100 Hz，以便于示波器显示。由于所需的电流调谐范围相当大，因此可以使用固定光纤衰减器来保持在所用检波器的功率限制范围内。衰减器可以直接安装在隔离器之后。
步骤6和步骤7中使用的UV固化粘合剂对激光透明，折射率为1.56。如步骤7.1中所述，对准过程取决于可用的光电探测器。此设置中使用的平衡检测器产生负电压“信号”输出。出于通用原因，在步骤7.10和 图6中的描述中假设为正电压输出。对于排列良好的标准具，反射率峰值将趋于零，而三角函数将增加其峰峰值比。
对于步骤8.1中的标准具表征，使用数值计算软件（见 材料表）。对每个温度阶跃的测量电压进行平均并绘制图表，如图 7所示。为了将温度步进转换为波长步进，使用探针激光器的温度调谐系数。信号分析库集成了寻峰算法，可用于此目的。由于数据分析在很大程度上取决于数据格式，因此此处不提供代码，但可以根据要求由相应的作者提供。
这里介绍的制造技术的一个可能的局限性是变化环境中的热稳定性和机械稳定性。由于本教学论文的范围是用于实验室应用的FPE的低成本原型设计，因此此处未给出有关机械和温度稳定性的测试。如果FPE用于移动应用或不断变化的环境，则必须采取额外的措施，以便相对于标准具对光纤GRIN镜片系统进行机械稳定。
这里展示了一种制造和表征FPE的新方法，每个光子实验室都提供标准光学元件。所提出的FPE具有大约15的精细度和足以检测约5 ppmV水蒸气的灵敏度。除了介绍的PTI应用外，该FPE还可用于诸如构建光学麦克风20之类的应用，这些应用通常用于无损检测23，折射率测量24，25或湿度计26，仅举几例。

在其最基本的形式中，FPE 由两个平面平行的部分反射镜面1 组成。在下面的解释中，当提到反射镜时，光学基板和反射涂层是一体的。在大多数应用中，使用的反射镜具有一个楔形表面2，以防止不必要的标准具效应。图1说明了空气间隔标准具的干涉图样的形成（图1A），以及不同镜面反射率的反射率函数（图1B）。
光通过一面镜子进入腔体，经过多次反射，并通过反射和透射离开腔体。由于本文重点介绍在反射率下操作的FPE的制造，因此进一步的解释专门涉及反射。离开腔体的波会干扰，具体取决于相位差， q = 4πnd/λ。这里， n 是腔内的折射率， d 是镜间距，λ是干涉仪光源的波长，这里称为探针激光器。当光程差与波长的整数倍匹配时， <img alt="Equation 2" src="/files/ftp_upload/65174/65174eq02.jpg" style="margin: auto;">将出现最小反射率。理想平面平行标准具的精细程度仅由镜面反射率 R1 和 R2 3 决定：
<img alt="Equation 3" src="/files/ftp_upload/65174/65174eq03.jpg" style="margin: auto;">
然而，真正的标准具会受到许多损失，这会降低理论上可实现的技巧4，5，6。镜平行度的偏差7，激光束的非正常入射，光束形状8，镜面杂质和散射等导致精细度降低。特征干涉图样可以用艾里函数1来描述：
<img alt="Equation 4" src="/files/ftp_upload/65174/65174eq04.jpg" style="margin: auto;">
半峰全宽（FWHM）以及反射率函数的自由光谱范围（FSR）可以计算如下：
<img alt="Equation 5" src="/files/ftp_upload/65174/65174eq05.jpg" style="margin: auto;">
<img alt="Equation 6" src="/files/ftp_upload/65174/65174eq06.jpg" style="margin: auto;">
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/65174/65174fig01.jpg"> 图1：法布里-佩罗干涉仪理论 。 （A）具有楔形窗口的空气间隔标准具的多光束干涉示意图。平面波E0 φ以一定角度通过减反射（AR）涂层表面进入空腔，随后在间隔一定距离d的高反射（高R）表面之间经历多次反射。每次反射时，部分光在透射或反射中与标准具耦合，在那里它与其他波相干扰。（B）理想法布里-佩罗标准具对不同镜面反射率（y轴）的反射率函数。 <a href="https://jove.unicartagenaproxy.elogim.com/files/ftp_upload/65174/65174fig01large.jpg" target="_blank">请点击此处查看此图的大图。</a>
FPE可以在广泛的应用中找到9，10，11。在这里介绍的案例中，FPE用于光热干涉测量（PTI）设置。在PTI中，通过干涉测量测量小密度和折射率变化，这是由周期性激发引起的，然后通过第二激光对目标气体进行快速热化12。热量以及折射率变化的大小与气体浓度成正比。当测量FPE在其最陡点（操作点）的反射率函数强度时，这些折射率变化会移动反射率函数，从而改变测量的强度。由于可以假设反射率函数在工作点周围的区域中是线性的，因此测量信号与气体浓度成正比。传感器的灵敏度由反射率函数的斜率决定，因此与精细度成正比。PTI 与 FPE 结合使用已被证明是一种灵敏且选择性的方法，可用于检测痕量气体和气溶胶13，14，15，16，17，18。过去，许多用于压力和声学测量的传感器依赖于使用可移动部件（如膜）来代替FPE19的第二面镜子。膜的偏转导致反射镜距离的变化，从而导致光程长度的变化。这些仪器的缺点是容易产生机械振动。近年来，使用固体FPE的光学麦克风的开发已达到20级商业水平。通过避免使用可移动部件，被测物从距离变为法布里-佩罗腔内的折射率，从而显着提高了传感器的坚固性。
市售的空隙FPE的成本超出了原型设计和测试以及大批量生产仪器集成的可接受范围。大多数构建和使用这种FPE的科学出版物只讨论制造的主题最少21，22。在大多数情况下，特定的设备和机器（例如，洁净室，涂层设施等）是必要的;例如，对于完全光纤集成的FPE，需要特殊的微加工设备。为了降低制造成本并能够测试多种不同的 FPE 配置以提高其对 PTI 设置的适用性，开发了一种新的制造方法，将在以下协议中详细描述。通过仅使用市售的标准散装光纤和电信光纤组件，制造成本可以降低到不到400欧元。每个使用标准光子设备的设施都应该能够复制我们的制造方案，并使其适应他们的应用。

<table><tbody><tr><td>Auto-Balanced Photoreceiver Nirvana</td><td>New Focus, Inc.</td><td>2017</td><td>Balanced Photodetector</td></tr><tr><td>Benchtop laser diode/TEC controller, 1A/96 W</td><td>Thorlabs</td><td>ITC4001</td><td></td></tr><tr><td>Butterfly laser diode mount</td><td>Thorlabs</td><td>LM14S2</td><td></td></tr><tr><td>Clamping fork</td><td>Thorlabs</td><td>CF175</td><td></td></tr><tr><td>compactRIO</td><td>National Instruments</td><td></td><td>For data aquisition</td></tr><tr><td>Dust remover</td><td>RS Components</td><td>168-1644</td><td></td></tr><tr><td>FC/APC to FC/APC Single L-Bracket Mating Sleeve</td><td>Thorlabs</td><td>ADAFCB3</td><td>Multiple needed</td></tr><tr><td>Fiber cleaning fluid</td><td>Thorlabs</td><td>RCS3</td><td></td></tr><tr><td>Fiber optic SM circulator</td><td>AFW technologies</td><td>CIR-3-15-L-1-2</td><td></td></tr><tr><td>Fiber optic SM coupler 1 x 2, 90/10</td><td>AFW technologies</td><td>FOBC-1-15-10-L-1-S-2</td><td>Only if balanced photodetector is used</td></tr><tr><td>Fiber optic SM isolator</td><td>AFW technologies</td><td>ISOD-15-L-1-2</td><td></td></tr><tr><td>Fiber optic storage reels</td><td>Thorlabs</td><td>FSR1</td><td>Multiple needed</td></tr><tr><td>Fixed fiber optic attenuator</td><td>Thorlabs</td><td>FA15T-APC</td><td>Different attenuation levels used</td></tr><tr><td>GRIN/Ferrule Sleeve, 1.818 mm Internal Diameter, 10 mm Length, Borosilicate Glass</td><td>Thorlabs</td><td>51-2800-1800</td><td>Fiber-GRIN-lens system</td></tr><tr><td>GRIN Lens, &amp;Oslash;1.8 mm, 0.23 Pitch, 8&amp;deg;, 1560 nm Design Wavelength, AR Coated: 1250 - 1650 nm</td><td>Thorlabs</td><td>GRIN2315A</td><td>Fiber-GRIN-lens system</td></tr><tr><td>Handheld UV-LED lamp</td><td>RS Components</td><td>220-6819</td><td>Lamp for curing the adhesive&amp;nbsp;</td></tr><tr><td>High precision stage and base</td><td>Newport</td><td>9062-X-M</td><td>Three nedded</td></tr><tr><td>Hose conector</td><td>RS Components</td><td></td><td>M5 threaded</td></tr><tr><td>Large Goniometer, 44.5 mm Distance to Point of Rotation, &amp;plusmn;5&amp;deg;, Metric</td><td>Thorlabs</td><td>GNL18/M</td><td>Two needed</td></tr><tr><td>L-Bracket Mating Sleeve</td><td>Thorlabs</td><td>ADAFCB3</td><td></td></tr><tr><td>Magnetic button clamps</td><td>Thorlabs</td><td>BM075</td><td>Multiple needed</td></tr><tr><td>Micrometer screw</td><td>Newport</td><td>9355</td><td>Three nedded</td></tr><tr><td>MIL-A-3920 Optical Adhesive with Resiliency, 1 oz.</td><td>Thorlabs</td><td>NOA61</td><td>UV-curing adhesive</td></tr><tr><td>Mounting Base, 50 mm x 75 mm x 10 mm</td><td>Thorlabs</td><td>BA2/M</td><td></td></tr><tr><td>O-Rings</td><td>Haberkorn</td><td></td><td>Sizes given in text</td></tr><tr><td>Passive component fiber tray</td><td>Thorlabs</td><td>BFCT</td><td>Multiple needed</td></tr><tr><td>Pedestal base adapter</td><td>Thorlabs</td><td>BE1</td><td></td></tr><tr><td>Pigtailed Ferrule, &amp;Oslash;1.8 mm, 8&amp;deg;, FC/APC, AR Coated: 1310/1550 nm</td><td>Thorlabs</td><td>SMPF0115-APC</td><td>Fiber-GRIN-lens system</td></tr><tr><td>Post holder</td><td>Thorlabs</td><td>PH30/M</td><td></td></tr><tr><td>Post-Mountable &amp;Oslash;2.5 mm Ferrule Clamp, M4 Tap</td><td>Thorlabs</td><td>FCM/M</td><td></td></tr><tr><td>Python</td><td>Python</td><td>3.9</td><td>Numerical data analysis software</td></tr><tr><td>Right-angled-bracket</td><td>Newport</td><td>9062-A-M</td><td></td></tr><tr><td>Self-centering lens mount</td><td>Thorlabs</td><td>SCL03</td><td></td></tr><tr><td>Silberschnitt 3001</td><td>Bohle&amp;nbsp;</td><td>3001</td><td>Glas cutter set</td></tr><tr><td>SM1-threaded standard cage plate</td><td>Thorlabs</td><td>CP33/M</td><td></td></tr><tr><td>UV-curing device</td><td>Formlabs</td><td>Form Cure</td><td></td></tr><tr><td>1550 nm 20 mW butterfly DFB laser diode</td><td>AeroDiode</td><td>1550LD-5-0-0-2</td><td></td></tr><tr><td>3D-printer</td><td>Formlabs</td><td>3+</td><td></td></tr><tr><td>&amp;Oslash;1/2&quot; UVFS Broadband Precision Window, Uncoated, t = 3 mm</td><td>Thorlabs</td><td>WG40530</td><td>Spacers</td></tr><tr><td>&amp;Oslash;1/2&quot; Broadband Dielectric Mirror, 1280 - 1600 nm</td><td>Thorlabs</td><td>BB05-E04</td><td>Mirror</td></tr><tr><td>&amp;Oslash;1/2&quot; 70:30 (R:T) UVFS Plate Beamsplitter, Coating: 1.2 - 1.6 &amp;micro;m, t = 3 mm</td><td>Thorlabs</td><td>BST06</td><td>Beamsplitter</td></tr></tbody></table>

fabrication of a low-cost, fiber-coupled, and air-spaced fabry-p&#233;rot etalon

法布里-佩罗标准具 （FPE） 已进入许多应用。在光谱学、电信和天文学等领域，FPE 因其高灵敏度和出色的过滤能力而被使用。然而，具有高精细度的空气间隔标准具通常由专门的设施建造。它们的生产需要洁净室、特殊的玻璃处理和镀膜机械，这意味着市售 FPE 的价格很高。本文提出了一种利用标准光子实验室设备制造光纤耦合FPE的新型且经济高效的方法。该协议应作为构建和表征这些FPE的分步指南。 我们希望这将使研究人员能够针对各种应用领域对FPE进行快速且具有成本效益的原型设计。此处介绍的FPE用于光谱应用。如代表性结果部分所示，通过环境空气中水蒸气的原理测量证明，该FPE的精细度为15 ， 足以对痕量气体进行光热检测。

如图7所示，可以制造具有明确定义的反射函数的FPE。
<img alt="Figure 7" class="xfigimg" src="/files/ftp_upload/65174/65174fig07.jpg"> 图 7：成品 FPE 的测量反射率函数。 执行对应于激光波长扫描的温度扫描以测量FPE的反射率函数。这用于评估制造设备的半峰全宽 （FWHM） 和自由光谱范围 （FSR） 等指标。相对反射率是指光通过FPE后背反射到光纤中的相对比例。 <a href="https://jove.unicartagenaproxy.elogim.com/files/ftp_upload/65174/65174fig07large.jpg" target="_blank">请点击此处查看此图的大图。</a>
FPE的测量指标列于 表1 中，并与具有相同规格的理想标准具的计算值进行比较。理想FPE的公式可以在介绍部分找到。
<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always"><tbody><tr><td></td>
			<td>量过的</td>
			<td>理想的 FPE</td>
		</tr><tr><td>手腕</td>
			<td>12.8</td>
			<td>17.1</td>
		</tr><tr><td>富华姆</td>
			<td>0.0268海里</td>
			<td>0.0234海里</td>
		</tr><tr><td>FSR</td>
			<td>0.3441海里</td>
			<td>0.4004海里</td>
		</tr><tr><td>敏感性</td>
			<td>14 1/纳米</td>
			<td>21 1/纳米</td>
		</tr></tbody></table>表 1：制造的 FPE 标准具的测量和计算指标的比较。
为了验证指定应用的能力，FPE用于环境空气中水蒸气的PTI测量。因此，波长为 1，364 nm 的激发激光垂直于探针激光器被引导到细胞中。两个激光器在FPE内相交。激发激光器以 125 Hz 的频率进行正弦调制。通过恒定电流 将 探头激光器稳定在FPE的最陡坡上，可以实现传感器的最高灵敏度。对于水蒸气测量，电池在打开的窗户下操作，并暴露在环境空气中，浓度为13，762 ppmV，由参考设备测量（温度= 21.4°C，压力= 979.9 hPa，相对湿度= 52.2%）。通过快速傅里叶变换（FFT）提取信号，并与关闭激发激光器的背景信号进行比较，如图 8所示。可以获得超过 7，000 的信噪比，对应于大约 5 ppmV （3σ） 的检测限。
<img alt="Figure 8" class="xfigimg" src="/files/ftp_upload/65174/65174fig08.jpg"> 图 8：环境空气中水蒸气的 PTI 测量值。 黑色表示125 Hz激光激发测量的FFT信号。蓝色表示无激励的背景信号。插图更详细地显示了 125 Hz 处的测量峰值。 <a href="https://jove.unicartagenaproxy.elogim.com/files/ftp_upload/65174/65174fig08large.jpg" target="_blank">请点击此处查看此图的大图。</a>
补充编码文件 1：Measurement_cell。斯普尔特。 测量单元的 CAD 文件。该单元可以适应特定应用的要求，并随后进行3D打印。 <a href="https://jove.unicartagenaproxy.elogim.com/files/ftp_upload/65174/measurement_cell.zip" target="_blank">请点击此处下载此文件。</a>
补充编码文件 2：cap_etalon。斯普尔特。 用于将标准具固定在测量单元内的CAD文件。 <a href="https://jove.unicartagenaproxy.elogim.com/files/ftp_upload/65174/cap_etalon.zip" target="_blank">请点击此处下载此文件。</a>
补充编码文件 3：cap_window。斯普尔特。 用于将激光窗口固定到测量单元上的CAD文件。 <a href="https://jove.unicartagenaproxy.elogim.com/files/ftp_upload/65174/cap_window.zip" target="_blank">请点击此处下载此文件。</a>

Watch this Scientific Journal Video about Fabrication of a Low-Cost, Fiber-Coupled, and Air-Spaced Fabry-Pérot Etalon at JoVE.com

作者聚焦：低成本、光纤耦合和空气间隔法布里-佩罗标准具的制造  

该协议描述了具有各种应用的低成本，离散，光纤耦合和空气间隔的法布里 - 珀罗标准具的构建，例如在痕量气体光谱中。可以在任何具有标准光学实验室设备的设施中进行制造。

制造低成本、光纤耦合和空气间隔的法布里-佩罗标准具

Fabry-P&#233;rot etalons (FPE) have found their way into many applications. In fields such as spectroscopy, telecommunications, and astronomy, FPEs are ...

在电气测量和传感器系统研究所的博士论文范围内，我正在评估光热气体和气溶胶传感器的小型化潜力。为了使光子传感器更加坚固和通用，或者低成本和小型化，投入了大量精力，但是将这些目标与必要的选择性和灵敏度相结合是非常具有挑战性的。我们的协议的主要优点在于该方法易于访问。无需洁净室或特殊机器，我们的协议提供了使用标准光子设备进行经济高效的原型设计的机会。我们希望我们的协议能够使研究人员能够以时间和经济高效的方式快速轻松地对多种标准具配置进行原型设计。我们将继续致力于光子气溶胶和气体传感器的小型化。我们将通过利用结构光和结构物质之间的相互作用来关注新的传感原理。

fabrication-low-cost-fiber-coupled-air-spaced-fabry-prot

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Unit 1

Fabrication of a Low-Cost, Fiber-Coupled, and Air-Spaced Fabry-P&#233;rot Etalon

Freezing and Thawing in Concrete

SCIENTISTS IN ACTION

5.3K 次观看.  Technical University of Graz. 在电气测量和传感器系统研究所的博士论文范围内，我正在评估光热气体和气溶胶传感器的小型化潜力。为了使光子传感器更加坚固和通用，或者低成本和小型化，投入了大量精力，但是将这些目标与必要的选择性和灵敏度相结合是非常具有挑战性的。我们的协议的主要优点在于该方法易于访问。无需洁净室或特殊机器，我们的协议提供了使用标准光子设备进行经济高?...

视频: 作者聚焦：低成本、光纤耦合和空气间隔法布里-佩罗标准具的制造  

Fabrication, Densification, and Replica Molding of 3D Carbon Nanotube Microstructures

The introduction of new materials and processes to microfabrication has, in large part, enabled many important advances in microsystems, lab-on-a-chip devices, and their applications. In particular, capabilities for cost-effective fabrication of polymer microstructures were transformed by the advent of soft lithography and other micromolding techniques 1, 2, and this led a revolution in applications of microfabrication to biomedical engineering and biology. Nevertheless, it remains challenging to fabricate microstructures with well-defined nanoscale surface textures, and to fabricate arbitrary 3D shapes at the micro-scale. Robustness of master molds and maintenance of shape integrity is especially important to achieve high fidelity replication of complex structures and preserving their nanoscale surface texture. The combination of hierarchical textures, and heterogeneous shapes, is a profound challenge to existing microfabrication methods that largely rely upon top-down etching using fixed mask templates. On the other hand, the bottom-up synthesis of nanostructures such as nanotubes and nanowires can offer new capabilities to microfabrication, in particular by taking advantage of the collective self-organization of nanostructures, and local control of their growth behavior with respect to microfabricated patterns. 
Our goal is to introduce vertically aligned carbon nanotubes (CNTs), which we refer to as CNT "forests", as a new microfabrication material. We present details of a suite of related methods recently developed by our group: fabrication of CNT forest microstructures by thermal CVD from lithographically patterned catalyst thin films; self-directed elastocapillary densification of CNT microstructures; and replica molding of polymer microstructures using CNT composite master molds. In particular, our work shows that self-directed capillary densification ("capillary forming"), which is performed by condensation of a solvent onto the substrate with CNT microstructures, significantly increases the packing density of CNTs. This process enables directed transformation of vertical CNT microstructures into straight, inclined, and twisted shapes, which have robust mechanical properties exceeding those of typical microfabrication polymers. This in turn enables formation of nanocomposite CNT master molds by capillary-driven infiltration of polymers. The replica structures exhibit the anisotropic nanoscale texture of the aligned CNTs, and can have walls with sub-micron thickness and aspect ratios exceeding 50:1. Integration of CNT microstructures in fabrication offers further opportunity to exploit the electrical and thermal properties of CNTs, and diverse capabilities for chemical and biochemical functionalization 3.

We present methods for fabrication of patterned microstructures of vertically aligned carbon nanotubes (CNTs), and their use as master molds for production of polymer microstructures with organized nanoscale surface texture. The CNT forests are densified by condensation of solvent onto the substrate, which significantly increases their packing density and enables self-directed formation of 3D shapes.

制备，致密，副本三维碳纳米管微结构成型

The introduction of new materials and processes to microfabrication has, in large part, enabled many important advances in microsystems, lab-on-a-chip ...

科研

工程学

Fabricating Metamaterials Using the Fiber Drawing Method

Metamaterials are man-made composite materials, fabricated by assembling components much smaller than the wavelength at which they operate 1. They owe their electromagnetic properties to the structure of their constituents, instead of the atoms that compose them. For example, sub-wavelength metal wires can be arranged to possess an effective electric permittivity that is either positive or negative at a given frequency, in contrast to the metals themselves 2. This unprecedented control over the behaviour of light can potentially lead to a number of novel devices, such as invisibility cloaks 3, negative refractive index materials 4, and lenses that resolve objects below the diffraction limit 5. However, metamaterials operating at optical, mid-infrared and terahertz frequencies are conventionally made using nano- and micro-fabrication techniques that are expensive and produce samples that are at most a few centimetres in size 6-7. Here we present a fabrication method to produce hundreds of meters of metal wire metamaterials in fiber form, which exhibit a terahertz plasmonic response 8. We combine the stack-and-draw technique used to produce microstructured polymer optical fiber 9 with the Taylor-wire process 10, using indium wires inside polymethylmethacrylate (PMMA) tubes. PMMA is chosen because it is an easy to handle, drawable dielectric with suitable optical properties in the terahertz region; indium because it has a melting temperature of 156.6 &deg;C which is appropriate for codrawing with PMMA. We include an indium wire of 1 mm diameter and 99.99% purity in a PMMA tube with 1 mm inner diameter (ID) and 12 mm outside diameter (OD) which is sealed at one end. The tube is evacuated and drawn down to an outer diameter of 1.2 mm. The resulting fiber is then cut into smaller pieces, and stacked into a larger PMMA tube. This stack is sealed at one end and fed into a furnace while being rapidly drawn, reducing the diameter of the structure by a factor of 10, and increasing the length by a factor of 100. Such fibers possess features on the micro- and nano- scale, are inherently flexible, mass-producible, and can be woven to exhibit electromagnetic properties that are not found in nature. They represent a promising platform for a number of novel devices from terahertz to optical frequencies, such as invisible fibers, woven negative refractive index cloths, and super-resolving lenses.

Metamaterials at terahertz frequencies offer unique opportunities, but are challenging to fabricate in bulk. We adapt the fabrication procedure for microstructured polymer optical fibers to inexpensively fabricate metamaterials potentially on an industrial scale. We produce polymethylmethacrylate fibers containing ~10 &mu;m diameter indium wires separated by ~100 &mu;m, which exhibit a terahertz plasmonic response.

制造超材料使用光纤拉丝法

Metamaterials are man-made composite materials, fabricated by assembling components much smaller than the wavelength at which they operate 1. They owe ...

Fabrication And Characterization Of Photonic Crystal Slow Light Waveguides And Cavities

Slow light has been one of the hot topics in the photonics community in the past decade, generating great interest both from a fundamental point of view and for its considerable potential for practical applications. Slow light photonic crystal waveguides, in particular, have played a major part and have been successfully employed for delaying optical signals1-4 and the enhancement of both linear5-7 and nonlinear devices.8-11
Photonic crystal cavities achieve similar effects to that of slow light waveguides, but over a reduced band-width. These cavities offer high Q-factor/volume ratio, for the realization of optically12 and electrically13 pumped ultra-low threshold lasers and the enhancement of nonlinear effects.14-16 Furthermore, passive filters17 and modulators18-19 have been demonstrated, exhibiting ultra-narrow line-width, high free-spectral range and record values of low energy consumption.
To attain these exciting results, a robust repeatable fabrication protocol must be developed. In this paper we take an in-depth look at our fabrication protocol which employs electron-beam lithography for the definition of photonic crystal patterns and uses wet and dry etching techniques. Our optimised fabrication recipe results in photonic crystals that do not suffer from vertical asymmetry and exhibit very good edge-wall roughness. We discuss the results of varying the etching parameters and the detrimental effects that they can have on a device, leading to a diagnostic route that can be taken to identify and eliminate similar issues.
The key to evaluating slow light waveguides is the passive characterization of transmission and group index spectra. Various methods have been reported, most notably resolving the Fabry-Perot fringes of the transmission spectrum20-21 and interferometric techniques.22-25 Here, we describe a direct, broadband measurement technique combining spectral interferometry with Fourier transform analysis.26 Our method stands out for its simplicity and power, as we can characterise a bare photonic crystal with access waveguides, without need for on-chip interference components, and the setup only consists of a Mach-Zehnder interferometer, with no need for moving parts and delay scans.
When characterising photonic crystal cavities, techniques involving internal sources21 or external waveguides directly coupled to the cavity27 impact on the performance of the cavity itself, thereby distorting the measurement. Here, we describe a novel and non-intrusive technique that makes use of a cross-polarised probe beam and is known as resonant scattering (RS), where the probe is coupled out-of plane into the cavity through an objective. The technique was first demonstrated by McCutcheon et al.28 and further developed by Galli et al.29

Use of photonic crystal slow light waveguides and cavities has been widely adopted by the photonics community in many differing applications. Therefore fabrication and characterization of these devices are of great interest. This paper outlines our fabrication technique and two optical characterization methods, namely: interferometric (waveguides) and resonant scattering (cavities).

光子晶体慢光波导和腔体的制备与表征

Slow light has been one of the hot topics in the photonics community in the past decade, generating great interest both from a fundamental point of view ...

Fabrication and Characterization of Disordered Polymer Optical Fibers for Transverse Anderson Localization of Light

We develop and characterize a disordered polymer optical fiber that uses transverse Anderson localization as a novel waveguiding mechanism. The developed polymer optical fiber is composed of 80,000 strands of poly (methyl methacrylate) (PMMA) and polystyrene (PS) that are randomly mixed and drawn into a square cross section optical fiber with a side width of 250 &mu;m. Initially, each strand is 200 &mu;m in diameter and 8-inches long. During the mixing process of the original fiber strands, the fibers cross over each other; however, a large draw ratio guarantees that the refractive index profile is invariant along the length of the fiber for several tens of centimeters. The large refractive index difference of 0.1 between the disordered sites results in a small localized beam radius that is comparable to the beam radius of conventional optical fibers. The input light is launched from a standard single mode optical fiber using the butt-coupling method and the near-field output beam from the disordered fiber is imaged using a 40X objective and a CCD camera. The output beam diameter agrees well with the expected results from the numerical simulations. The disordered optical fiber presented in this work is the first device-level implementation of 2D Anderson localization, and can potentially be used for image transport and short-haul optical communication systems.

We develop and characterize a disordered polymer optical fiber that uses transverse Anderson localization as a novel waveguiding mechanism. This microstructured fiber can transport a small localized beam with a radius that is comparable to the beam radius of conventional optical fibers.

无序横向安德森本地化光聚合物光纤的制备和表征

We develop and characterize a disordered polymer optical fiber that uses transverse Anderson localization as a novel waveguiding mechanism. The developed ...

Fabrication and Testing of Microfluidic Optomechanical Oscillators

Cavity optomechanics experiments that parametrically couple the phonon modes and photon modes have been investigated in various optical systems including microresonators. However, because of the increased acoustic radiative losses during direct liquid immersion of optomechanical devices, almost all published optomechanical experiments have been performed in solid phase. This paper discusses a recently introduced hollow microfluidic optomechanical resonator. Detailed methodology is provided to fabricate these ultra-high-Q microfluidic resonators, perform optomechanical testing, and measure radiation pressure-driven breathing mode and SBS-driven whispering gallery mode parametric vibrations. By confining liquids inside the capillary resonator, high mechanical- and optical- quality factors are simultaneously maintained.

Parametric optomechanical excitations have recently been experimentally demonstrated in microfluidic optomechanical resonators by means of optical radiation pressure and stimulated Brillouin scattering. This paper describes the fabrication of these microfluidic resonators along with methodologies for generating and verifying optomechanical oscillations.

制造和微流控光机振荡器测试

Cavity optomechanics experiments that parametrically couple the phonon modes and photon modes have been investigated in various optical systems including ...

Fabrication and Operation of a Nano-Optical Conveyor Belt

The technique of using focused laser beams to trap and exert forces on small particles has enabled many pivotal discoveries in the nanoscale biological and physical sciences over the past few decades. The progress made in this field invites further study of even smaller systems and at a larger scale, with tools that could be distributed more easily and made more widely available. Unfortunately, the fundamental laws of diffraction limit the minimum size of the focal spot of a laser beam, which makes particles smaller than a half-wavelength in diameter hard to trap and generally prevents an operator from discriminating between particles which are closer together than one half-wavelength. This precludes the optical manipulation of many closely-spaced nanoparticles and&#160;limits the&#160;resolution of optical-mechanical systems. Furthermore, manipulation using focused beams requires beam-forming or steering optics, which can be very bulky and expensive. To address these limitations in the system scalability of conventional optical trapping our lab has devised an alternative technique which utilizes near-field optics to move particles across a chip. Instead of focusing laser beams in the far-field, the optical near field of plasmonic resonators produces the necessary local optical intensity enhancement to overcome the restrictions of diffraction and manipulate particles at higher resolution. Closely-spaced resonators produce strong optical traps which can be addressed to mediate the hand-off of particles from one to the next in a conveyor-belt-like fashion. Here, we describe how to design and produce a conveyor belt using a gold surface patterned with plasmonic C-shaped resonators and how to operate it with polarized laser light to achieve super-resolution nanoparticle manipulation and transport. The nano-optical conveyor belt chip can be produced using lithography techniques and easily packaged and distributed.

The scalability and resolution of conventional optical manipulation techniques are limited by diffraction. We circumvent the diffraction limit and describe a method of optically transporting nanoparticles across a chip using a gold surface patterned with a path of closely spaced C-shaped plasmonic resonators.

一个纳米光输送带的制作和操作

The technique of using focused laser beams to trap and exert forces on small particles has enabled many pivotal discoveries in the nanoscale biological ...

Fabrication of High Contrast Gratings for the Spectrum Splitting Dispersive Element in a Concentrated Photovoltaic System

High contrast gratings are designed and fabricated and its application is proposed in a parallel spectrum splitting dispersive element that can improve the solar conversion efficiency of a concentrated photovoltaic system. The proposed system will also lower the solar cell cost in the concentrated photovoltaic system by replacing the expensive tandem solar cells with the cost-effective single junction solar cells. The structures and the parameters of high contrast gratings for the dispersive elements were numerically optimized. The large-area fabrication of high contrast gratings was experimentally demonstrated using nanoimprint lithography and dry etching. The quality of grating material and the performance of the fabricated device were both experimentally characterized. By analyzing the measurement results, the possible side effects from the fabrication processes are discussed and several methods that have the potential to improve the fabrication processes are proposed, which can help to increase the optical efficiency of the fabricated devices.

The fabrication of high contrast gratings as the parallel spectrum splitting dispersive element in a concentrated photovoltaic system is demonstrated. Fabrication processes including nanoimprint lithography, TiO2 sputtering and reactive ion etching are described. Reflectance measurement results are used to characterize the optical performance.

制造高对比度光栅的频谱分割色散元件的聚光光伏系统

High contrast gratings are designed and fabricated and its application is proposed in a parallel spectrum splitting dispersive element that can improve ...

Fabrication of 1-D Photonic Crystal Cavity on a Nanofiber Using Femtosecond Laser-induced Ablation

We present a protocol for fabricating 1-D Photonic Crystal (PhC) cavities on subwavelength-diameter tapered optical fibers, optical nanofibers, using femtosecond laser-induced ablation. We show that thousands of periodic nano-craters are fabricated on an optical nanofiber by irradiating with just a single femtosecond laser pulse. For a typical sample, periodic nano-craters with a period of 350 nm and with diameter gradually varying from 50 - 250 nm over a length of 1 mm are fabricated on a nanofiber with diameter around 450 - 550 nm. A key aspect of such a nanofabrication is that the nanofiber itself acts as a cylindrical lens and focuses the femtosecond laser beam on its shadow surface. Moreover, the single-shot fabrication makes it immune to mechanical instabilities and other fabrication imperfections. Such periodic nano-craters on nanofiber, act as a 1-D PhC and enable strong and broadband reflection while maintaining the high transmission out of the stopband. We also present a method to control the profile of the nano-crater array to fabricate apodized and defect-induced PhC cavities on the nanofiber. The strong confinement of the field, both transverse and longitudinal, in the nanofiber-based PhC cavities and the efficient integration to the fiber networks, may open new possibilities for nanophotonic applications and quantum information science.

We present a protocol for fabricating 1-D photonic crystal cavities on subwavelength diameter silica fibers (optical nanofibers) using femtosecond laser-induced ablation.

1-D光子晶体空穴对纳米纤维使用飞秒激光诱导消融制造

We present a protocol for fabricating 1-D Photonic Crystal (PhC) cavities on subwavelength-diameter tapered optical fibers, optical nanofibers, using ...

Fabrication of an Optical Cell Dryer for the Spectroscopic Analysis Cells

Optical cells, which are experimental instruments, are small, square tubes sealed on one side. A sample is placed in this tube, and a measurement is performed with a spectroscope. The materials used for optical cells generally include quartz glass or plastic, but expensive quartz glass is reused by removing substances, other than liquids, to be analyzed that adhere to the interior of the container. In such a case, the optical cells are washed with water or ethanol and dried. Then, the next sample is added and measured. Optical cells are dried naturally or with a manual hairdryer. However, drying takes time, which makes it one of the factors that increase the experiment time. In this study, the objective is to drastically reduce the drying time with a dedicated automatic dryer that can dry multiple optical cells at once. To realize this, a circuit was designed for a microcomputer, and the hardware using it was independently designed and manufactured.

A protocol for fabricating a device for simultaneously drying multiple optical cells is presented.

光谱分析细胞光学细胞干燥机的研制

Optical cells, which are experimental instruments, are small, square tubes sealed on one side. A sample is placed in this tube, and a measurement is ...

Low-cost Custom Fabrication and Mode-locked Operation of an All-normal-dispersion Femtosecond Fiber Laser for Multiphoton Microscopy

A protocol is presented to build a custom low-cost yet high-performance femtosecond (fs) fiber laser. This all-normal-dispersion (ANDi) ytterbium-doped fiber laser is built completely using commercially available parts, including $8,000 in fiber optic and pump laser components, plus $4,800 in standard optical components and extra-cavity accessories. Researchers new to fiber optic device fabrication may also consider investing in basic fiber splicing and laser pulse characterization equipment (~$63,000). Important for optimal laser operation, methods to verify true versus apparent (partial or noise-like) mode-locked performance are presented. This system achieves 70 fs pulse duration with a center wavelength of approximately 1,070 nm and a pulse repetition rate of 31 MHz. This fiber laser exhibits the peak performance that may be obtained for an easily assembled fiber laser system, which makes this design ideal for research laboratories aiming to develop compact and portable fs laser technologies that enable new implementations of clinical multiphoton microscopy and fs surgery.

A method is presented to build a custom low-cost, mode-locked femtosecond fiber laser for potential applications in multiphoton microscopy, endoscopy, and photomedicine. This laser is built using commercially available parts and basic splicing techniques.

用于多光子显微镜的全正常分散飞秒光纤激光器的低成本定制制造和模式锁定操作

A protocol is presented to build a custom low-cost yet high-performance femtosecond (fs) fiber laser. This all-normal-dispersion (ANDi) ytterbium-doped ...