The SAIL labs are funded through JBH's Australian Laureate Fellowship from the Australian Research Council.
This research was supported by the Australian Research Council Centre of Excellence for Ultrahigh bandwidth Devices for Optical Systems (project number CE110001018).
Experimental work was performed in part at the OptoFab node of the Australian National Fabrication Facility, utilizing NCRIS and NSW state government funding. Fiber hydrogenation services were provided by TE Connectivity in Redfern. SLS would like to acknowledge the Optics and Electronics Laboratory, Fujikura Ltd, Japan for providing the 7-core fiber used in this experiment.

1.抛光毛细管准备（ANFF OptoFab） <ol><li>得到具有紧密匹配纤维直径内直径的玻璃毛细管。在规模上接近，性能越好，但要确保在毛细管尺寸的±10微米的变化是允许的。从毛细管中删除任何保护涂层。刮掉涂层用刀片而不损坏管将其删除。 </li><li>如果需要，锥形毛细管到一个较小的直径。最好使用电脑控制全自动锥形机。 <ol><li>两端固定管道用夹子固定的长度。 </li><li>加热毛细管使用位于夹具之间热灯丝均匀熔点其直径周围。 </li><li>绘制通过带张力加热元件的毛细直至所需长度已经锥形的，以更小的直径。 </li></ol></li><li>切毛细管成大致相等长度的WiTH玻璃切割工具。确保这些比预期的光栅长度较长，但足够小以适合所使用的抛光设备内的至少2厘米。注意:对于这个实验中，使用7厘米的毛细管长度。 </li><li>附上毛细管长度的8-10使用紫外线固化型胶的玻璃冰球。安装冰球到具有研磨/抛光机兼容的夹具。 </li><li>使用研磨/抛光机的毛细管的暴露壁研磨成平坦面。注意:不要吸入松散沙砾。注意:研磨元件是的 Al 2 O 3中的悬浮液反渗透纯化水。 <ol><li>使用25微米的粒度，直到毛细管壁的剩余厚度约为70微米。使用千分尺磨削，因此已被去除的量期间测量夹具的位移。 </li><li>切换至5μm粒度和研磨，直到壁的剩余厚度约为50微米。 </li></ol&gt; </li><li>使用研磨/抛光机来抛光平坦​​表面用于与在碱性分散液（氢氧化钠）的高纯度胶体氧化硅的至少3小时。注:此恢复表面的光学质量。该二氧化硅可以通过加入1份0.004 M氢氧化钠至3份抛光溶液固化来防止。 </li><li>通过在丙酮中浸泡过夜分离从保持冰球毛细管。 </li><li>检查两端毛细管在显微镜下用10X放大率检查壁厚。注意:良好质量的毛细管将具有沿其长度具有均匀的薄（〜50微米）的墙。 </li></ol> 2.光栅的创建<ol><li>氢化MCF增加光敏性。 <ol><li>放置待氢化成气密密封腔室中的纤维。注意:确保该室用螺栓固定，由于加压气体的存在。 </li><li>泵的高纯度的 H 2到腔室。使用N 2 </子&gt;气体作为助推器以增加压力。 </li><li>离开腔室内部的纤维较长时间:2个星期，在300巴和室温下，或在380巴和80℃下3天。 </li><li>泄从室中的气体并取出纤维。注意:确保室内通风良好。气体可以作为asphyxiants，或在H 2的情况下火灾危险性。 </li><li>保持在冰箱中的纤维与温度-70℃以下，直到它们被使用。这减慢氢气脱气的速率和保留增加光敏性。 </li></ol></li><li>剥去从MCF保护涂层。条的MCFs相同尺寸与标准SMF纤维剥离的SMF;否则刮掉用刀片的涂层。从在光栅将被写入，一路到光纤的端部的区域除去涂层。 </li><li>插入光纤插入毛细管的剥离端，并且使得它覆盖区域到b沿纤维滑动管<html> Ë题写。 </li><li>戴上防紫外线眼镜。安装在其保持相位掩模的移动台的光纤，向相位掩模倾斜毛细管的扁平侧。确保纤维被定位在由掩模产生的干涉图案内，但不接触掩模本身，因为这可能会造成损害。 </li><li>对准244纳米的激光，使得光束是垂直于所述相位掩模的平坦表面。确保光纤接收至少90毫瓦的激光功率。 </li><li>通过以0.25毫米/分钟的速率相对于一起移动所述纤维和相掩模的入射光束暴露光纤到紫外干涉图案的4厘米长。 </li><li>从纤维中移除毛细管。 </li><li>退火在110℃的光栅20小时，以稳定的波长响应。注意:此步骤是可选的，因为光栅将自行在约3天的过程中稳定，但退火使得该方法更快。 </li></ol>e_title"&gt; 3。光谱分析<ol><li>切割纤维的两端。使用一个光纤切割刀，允许用户设置纤维直径和张力既保证平坦端表面。 </li><li>照亮使用具有中心波长约匹配的布拉格波长可调谐激光器的光纤的一端。 </li><li> CCD相机连接到PC控制软件来显示和记录光纤输出。图象光纤输出与CCD照相机，使用显微镜物镜与在摄像机前面50X放大率，以确保所有内核覆盖多个CCD的像素。注:以下步骤3.4.1 - 3.5.5特定于作者所使用的定制软件，并代表捕捉光谱只有一个方法。 <ol><li>当他们出现在控制软件在图像中选择点击的芯子的中心对应于每个核心像素的圆形区域。以像素单位中的"长度或直径＆进入芯的直径＃39;领域。 </li><li>记录由照相机所选地区注册的像素值。综上所述，用于覆盖给定的芯在该波长量化总吞吐量的所有像素的值。 </li></ol></li><li>可调谐激光器连接到控制计算机，使得观察和数据采集可以自动化。 <ol><li>在"开始波长"字段中输入波长的布拉格波长低于约5纳米。 </li><li>激光的波长增量为0.01纳米的&#39;扫描 - 步骤"字段。注意:这样被记录前测量值和下一个波长步骤发生时激射是在每个波长稳定步骤之间的延迟设置为至少300毫秒。 </li><li>输入的波长比在&#39;结束波长&#39;字段的布拉格波长大约为5nm以上。 </li><li>点击"自动扫描"按钮来设置激光的定义开始波长，并通过在单组选定的增量增加波长LAR的时间间隔。 </li><li>通过记录每个核心每个波长传送步力度。通过启用"文本文件保存"选项导出的计算值到一个文本文件中。 </li></ol></li><li>重复扫描的至少3倍，并从所有的运行平均的数据。 </li><li>积发射功率相对于波长的每个核心以产生一组光谱。 <ol><li>对比所有内核的光谱，以确认它们是否具有相同的抑制特性。检查每个光栅匹配的中心波长，深度和带宽。 </li></ol></li></ol>

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The authors declare that they have no competing financial interests.

图2和图 3一起显示，写入光栅时引入抛光毛细管（PCT）是足以改善MCFBG芯光谱的均匀性。碑文过程的其余部分是从用于创建SMF光栅，可与大多数现有光纤光栅书写系统可以使用已建立的方法基本上没有变化。因此，多氯三联苯准备在协议第2条所列是提高MCFBG均匀性最为关键。最好的结果是用管，其中所述抛光的壁具有一致的，小的厚度实现;这里所选择的50微米厚给出保持玻璃的强度和最小化纤维和相位掩模之间的距离之间的折衷。 然而，即使与PCT存在引起该MCF中间核心具有不同的波长响应于其他核心的附加效果。我们使用了不同的加氢章IME在协议部分中的步骤3.1如上所述调查是否变化是由在该芯下部氢吸收造成的，但没有观察到改善。的变化也不能由芯UV暴露过程中浇铸在彼此的阴影进行说明，因为这将导致外6芯还具有匹配很差的反应。代替的行为可以由中央纤芯具有不同的光学性质的其他，尽管制造时是相同的说明。 除非单纤维内的所有核心具有相同透射光谱MCFBGs不能作为有效的替代他们的SMF对应。我们打​​算与次级更正与PCT制成现有的MCFs实验，使用热和机械应力的影响，以移位所述外芯的布拉格波长以匹配中心。这篇文章中描述的实验也将重复较大的核心数，以确定转耳鼻喉科到阴影和径向布拉格波长变化的影响与规模的核心&#39;环&#39;的数量。 该技术是在效力目前仅限于非常大的纤维或高芯数的情况下。在前者的情况下，在一个大的纤维，该纤维是最远从入射光束的芯不暴露于干涉图案。这是因为，我们使用在这些实验中，限制最高写入深度的马赫 - 曾德尔干涉仪;出现这种情况的原因是干涉图案延伸超出相位掩模仅几百微米。我们打​​算解决这一与重新设计的萨格纳克干涉仪，其中将有景深未来实验至少两次，目前的设备。在第二种情况下的总核心数量大时，一些芯可以定位在由芯铸靠近相位掩模的阴影内。本上MCFBG质量的影响尚不清楚;我们将investiga德这与19-，37-，和使用上述方法55芯光纤。 这些实验表明，以光栅写入过程最小的，廉价的变化可以延长其适用性以外的SMF。一旦MCFBGs可以与过滤能力等于现有的SMF技术来创建，它们可以在光子学的任何应用中使用，允许紧凑和坚固的设备的结构而不会牺牲性能。正如前言所述，作者的主要目标是MCFBGs纳入新的天文仪器;然而，它们可以潜在地在已经利用单模光学和/或准确的波长滤波的任何系统中采用。像他们的单模同行MCFBGs可以根据应用透射和反射可以使用。

光纤布拉格光栅（光纤布拉格光栅）被广泛地用作窄带滤波器由于它们可以被定制为大量的应用程序1的事实。它们不限于抑制单一波长;复杂的透射光谱可通过使用非周期性折射率变化2的创建。一个限制是光纤布拉格光栅只能在单模光纤（SMF的）登记的，因为这被抑制对于一个给定的光栅周期的波长依赖于传播常数。在一个多模光纤（MMF），其中每个模式具有不同的传播常数，对于每个模式的抑制波长是不同的，因此光栅不会在任何单一波长给予强烈抑制。 这个实验的动力来自天文学。下视宁受限的条件，直接耦合到SMF是困难的，低效率的;极端自适应光学要求这样做3。正因为如此，磁动势是典型ically从望远镜焦平面4收集光时使用。因此，为了保持只提供给的SMF的功能，有必要具有的SMF和磁动势之间的有效转换。这是可能的光子灯笼，它由通过一个锥形过渡5相连的SMF的阵列的多模端口的装置。光子灯笼在直觉仪器，其中，所述的SMF含有光纤光栅从近红外观测6去除大气发射线（由OH自由基和其它分子）使用。使用单独的，单核的SMF此任务的缺点是它们必须由一个被写入一个，单独地剪接到光学系列，需要显著时间和人工劳动。在这篇文章中描述的技术试图解决使用更复杂的纤维格式，以提供所述单模式功能这些缺点。 下一代OH suppr分裂国家仪器PRAXIS 7将利用多芯光纤（的MCFs）的。这些纤维包含任何数量的嵌入在单包层单moded内核。这种方法的优点在于，MCF可以渐缩到与所得的光子灯笼作为一个紧凑和坚固的自包含单元中的MMF。在已完成的仪器，从望远镜光线会被耦合到灯笼的MMF端口;锥形过渡将该光分离成单模芯在那里将穿过光纤光栅。波长过滤剩余的光被分散到一个检测器之后，光谱收集。 使用同样的MCFs加快写作光栅的过程中，因为所有的内核可以在一个单一的传球内切。然而，写入过程必须按顺序进行修改，以确保所有的核心具有相同的反射特性。这是因为，包层的弯曲表面的光纤光栅，水库的侧写入期间充当透镜ulting中，如果使用标准的侧写入方法在每个芯中功率和方向而变化的紫外场。因此，每个芯将具有不同的传输特性文件，并且在一单一波长8的纤维将不提供强烈抑制。 海军研究实验室的一组修改内核的分布和光敏性取消这种变化9的效果试验。使用这种方法的缺点是光纤必须重新设计，包层尺寸，核心大小，内核和化学成分数量的每个组合。此外，由于缺乏在所得的设计轴对称意味着MCF不能有效地逐渐变细成一个环状铁心的MMF。本文详细介绍了不同的解决问题的方法:有它穿过一个平面上，而不是在曲面包覆直接入射修改纤维内的场。使用这种方法产生一个技术，它可以转移到各种MCF设计和尺寸，尤其是，我们希望将其纳入光子灯笼轴对称纤维。 创造了必要的平坦面，到MCF置于已研磨和抛光在一侧，得到平坦的外壁的UV透明毛细管内部。一个小的间隙，必须在纤维和毛细管之间留下，因为后者可以含有直径±10微米变化。参见图1为一个表示。本文将描述实验过程写在这种方式光纤光栅，并提供可能的改进例子。欲了解更多信息，请参阅先前公布的10模拟和实验结果11。 <img alt="图1" src="/files/ftp_upload/53326/53326fig1.jpg" /> 在FBG产品中使用图1抛光毛细管图离子该MCF放置在毛细管内。两者之间的间隙要小，但允许在直径小的变化。已经通过相位掩模通过紫外光然后进入通过毛细管平面侧系统。 <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/53326/53326fig1large.jpg" target="_blank">请点击此处查看该图的放大版本。</a>

<table border="0" cellpadding="0" cellspacing="0" width="1171">
	<tbody>
		<tr height="22">
			<td height="22" style="height:22px;width:216px;">Multicore fiber</td>
			<td style="width:148px;">Fujikura Ltd.</td>
			<td style="width:163px;"></td>
			<td style="width:645px;">7 cores with diameter 5.5 &#181;m, core separation 35 &#181;m, hexagonally arranged within 125 &#181;m cladding, NA = 0.177</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Glass tapering machine</td>
			<td style="width:148px;">Vytran</td>
			<td style="width:163px;">GPX-3000</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">UV laser</td>
			<td style="width:148px;">Coherent</td>
			<td style="width:163px;">300 FreD Innova</td>
			<td>Frequency doubled 244 nm, at least 150 mW output. CAUTION: eye damage; wear appropriate goggles</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Phase mask</td>
			<td style="width:148px;">Lasiris</td>
			<td style="width:163px;">PM-244-1069.50-50.8</td>
			<td>Custom component, 1069.50 nm grating period, 5.08 mm thickness</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Capillary tubes</td>
			<td style="width:148px;">Polymicro</td>
			<td>TSP200794</td>
			<td>Inner diameter 200 &#181;m, outer diameter 794 &#181;m</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Lapping machine</td>
			<td style="width:148px;">Logitech</td>
			<td style="width:163px;">PM5</td>
			<td>Combination grinder/polisher</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">UV-curable glue</td>
			<td style="width:148px;">Norland</td>
			<td style="width:163px;">NOA-61</td>
			<td>Cures rapidly, removable with acetone</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Microgrit</td>
			<td style="width:148px;">Eminess</td>
			<td style="width:163px;"></td>
			<td>Al2O3: 25 &#181;m and 5 &#181;m particle size</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Polishing fluid</td>
			<td style="width:148px;">Eminess</td>
			<td style="width:163px;">ULTRA-SOL 500S</td>
			<td>SF-500S-5, ULTRA-SOL 500S N/D, 5 GAL</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Sodium hydroxide</td>
			<td style="width:148px;"></td>
			<td style="width:163px;"></td>
			<td>0.004M</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Fiber cleaver</td>
			<td style="width:148px;">Vytran</td>
			<td style="width:163px;">LDC-400</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Tunable laser</td>
			<td style="width:148px;">JDS Uniphase</td>
			<td style="width:163px;">SWS15101</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">IR Camera</td>
			<td style="width:148px;">Xenics</td>
			<td style="width:163px;">XEVA-1429</td>
			<td>320x256 pixel, 16 bit resolution</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Oven</td>
			<td style="width:148px;">Thermoline Scientific</td>
			<td style="width:163px;">LDO-030N</td>
			<td>For annealing at T=110&#176;C</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Hydrogen gas</td>
			<td style="width:148px;">BOC</td>
			<td style="width:163px;"></td>
			<td>For hydrogenating fiber. CAUTION: flammable, pressurised gas</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Nitrogen gas</td>
			<td style="width:148px;">BOC</td>
			<td style="width:163px;"></td>
			<td>Booster for hydrogenation. CAUTION: pressurised gas</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Acetone</td>
			<td style="width:148px;"></td>
			<td style="width:163px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Razor blades</td>
			<td style="width:148px;"></td>
			<td style="width:163px;"></td>
			<td></td>
		</tr>
	</tbody>
</table>

writing bragg gratings in multicore fibers

Fiber Bragg gratings in multicore fibers can be used as compact and robust filters in astronomical and other research and commercial applications. Strong suppression at a single wavelength requires that all cores have matching transmission profiles. These gratings cannot be inscribed using the same method as for single-core fibers because the curved surface of the cladding acts as a lens, focusing the incoming UV laser beam and causing variations in exposure between cores. Therefore we use an additional optical element to ensure that the beam shape does not change while passing through the cross-section of the multicore fiber. This consists of a glass capillary tube which has been polished flat on one side, which is then placed over the section of the fiber to be inscribed. The laser beam enters the fiber through the flat surface of the capillary tube and hence maintains its original dimensions. This paper demonstrates the improvements in core-to-core uniformity for a 7-core fiber using this method. The technique can be generalized to larger multicore fibers.

此技术的有效性是最好通过比较多芯光纤布拉格光栅（MCFBGs），其从曝光具有和不具有毛细管导致表现出; 图2示出了7芯使用的SMF的标准方法MCF露出的传输特性，与个别通过不同的颜色表示芯光谱。有最小重叠的抑制波长之间，以及芯＃5已经接收导致一个浅切口较弱曝光。两种效应是由于在写入过程中的纤维内的功率变化。需要注意的是在-36分贝的平坦的截止是由于摄像机的有限的动态范围;所有的传输值相对于这个最低的比例。 <img alt="图2" src="/files/ftp_upload/53326/53326fig2.jpg" /> 图2. MCFBG性能没有补偿镜头内核ING。该图显示了当MCFBG被使用的SMF的标准方法生产各个芯的透射光谱。有缺口之间的最小重叠。核心编号的（插图）图。从以前的出版物11改编。 <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/53326/53326fig2large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> 在图3中，相同的数据示出了用于将其暴露毛细管内具有内径140微米的相同光纤。 （请注意，布拉格波长大约比在前面的情况下2纳米，该光栅被测量之前退火。铁心之间的变化之前和退火之后被保持。）在本MCFBG，6的7芯已很好对准凹口，与1548.25±0.01纳米为中心的重叠。未对准的芯，其位于中心纤维，具有布拉格波长100时比其他的短。具有这种不匹配的芯的作用是在纤维的总抑制限制到-8.5分贝;换句话说，1/7 次在1548.25处的光的可通过MCFBG自由通过。如果只有外芯包括在计算（ 即 ，芯＃1被阻塞或其他不亮），的&gt;36分贝一个最大抑制是可能的。这些结果示于图4以图形表示。 <img alt="图3" src="/files/ftp_upload/53326/53326fig3.jpg" /> 图3. MCFBG芯与抛光毛细管性能。与用来补偿透镜毛细管7芯光纤所有光栅的透射曲线。外六核的反射波长重叠于1548.25±0 0.01 nm左右。核心＃1的光栅响应，它位于所述策NTER纤维，朝向更短的波长偏移。核心编号的（插图）图。从以前的出版物11改编。 <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/53326/53326fig3large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> <img alt="图4" src="/files/ftp_upload/53326/53326fig4.jpg" /> 图4整体纤维性能的MCFBG。比较用（蓝色） 的整体性能和无（绿色）的中心芯包括在内。从以前的出版物11改编。 <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/53326/53326fig4large.jpg" target="_blank">请点击此处查看该图的放大版本。</a>

Watch this Scientific Journal Video about Writing Bragg Gratings in Multicore Fibers at JoVE.com

Writing Bragg Gratings in Multicore Fibers

We describe a technique for inscribing identical fiber Bragg gratings into each core of a multicore fiber. This is achieved by introducing an additional surface into the optical path to mitigate lensing by the curved surface of the fiber cladding.

写布拉格光栅在多核纤维

Fiber Bragg gratings in multicore fibers can be used as compact and robust filters in astronomical and other research and commercial applications. Strong ...

writing-bragg-gratings-in-multicore-fibers

Nanyang Technological University

Research

JoVE Journal

Engineering

8.1K 次观看.  University of Sydney. We describe a technique for inscribing identical fiber Bragg gratings into each core of a multicore fiber. This is achieved by introducing an additional surface into the optical path to mitigate lensing by the curved surface of the fiber cladding.

视频: Writing Bragg Gratings in Multicore Fibers

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 ...

科研

工程学

Writing and Low-Temperature Characterization of Oxide Nanostructures

Oxide nanoelectronics is a rapidly growing field which seeks to develop novel materials with multifunctional behavior at nanoscale dimensions. Oxide interfaces exhibit a wide range of properties that can be controlled include conduction, piezoelectric behavior, ferromagnetism, superconductivity and nonlinear optical properties. Recently, methods for controlling these properties at extreme nanoscale dimensions have been discovered and developed. Here are described explicit step-by-step procedures for creating LaAlO3/SrTiO3 nanostructures using a reversible conductive atomic force microscopy technique. The processing steps for creating electrical contacts to the LaAlO3/SrTiO3 interface are first described. Conductive nanostructures are created by applying voltages to a conductive atomic force microscope tip and locally switching the LaAlO3/SrTiO3 interface to a conductive state. A versatile nanolithography toolkit has been developed expressly for the purpose of controlling the atomic force microscope (AFM) tip path and voltage. Then, these nanostructures are placed in a cryostat and transport measurements are performed. The procedures described here should be useful to others wishing to conduct research in oxide nanoelectronics.

Oxide nanostructures provide new opportunities for science and technology. The interfacial conductivity between LaAlO3 and SrTiO3 can be controlled with near-atomic precision using a conductive atomic force microscopy technique. The protocol for creating and measuring conductive nanostructures at LaAlO3/SrTiO3 interfaces is demonstrated.

写作和氧化物纳米结构的低温特性

Oxide nanoelectronics is a rapidly growing field which seeks to develop novel materials with multifunctional behavior at nanoscale dimensions.  Oxide ...

Prescribed 3-D Direct Writing of Suspended Micron/Sub-micron Scale Fiber Structures via a Robotic Dispensing System

A 3-axis dispensing system is utilized to control the initiating and terminating fiber positions and trajectory via the dispensing software. The polymer fiber length and orientation is defined by the spatial positioning of the dispensing system 3-axis stages. The fiber diameter is defined by the prescribed dispense time of the dispensing system valve, the feed rate (the speed at which the stage traverses from an initiating to a terminating position), the gauge diameter of the dispensing tip, the viscosity and surface tension of the polymer solution, and the programmed drawing length. The stage feed rate affects the polymer solution&#8217;s evaporation rate and capillary breakup of the filaments. The dispensing system consists of a pneumatic valve controller, a droplet-dispensing valve and a dispensing tip. Characterization of the direct write process to determine the optimum combination of factors leads to repeatedly acquiring the desired range of fiber diameters. The advantage of this robotic dispensing system is the ease of obtaining a precise range of micron/sub-micron fibers onto a desired, programmed location via automated process control. Here, the discussed self-assembled micron/sub-micron scale 3D structures have been employed to fabricate suspended structures to create micron/sub-micron fluidic devices and bioengineered scaffolds.

Here, we present a protocol to fabricate freely-suspended, micron/sub-micron scale polymer fibers and &#8220;web-like&#8221; structures generated via automated direct writing procedure by means of a 3-axis dispensing system.

暂停规定微米/亚微米尺度的纤维结构的3-D直写经全自动点胶系统

A 3-axis dispensing system is utilized to control the initiating and terminating fiber positions and trajectory via the dispensing software. The polymer ...

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 ...

Detection and Recovery of Palladium, Gold and Cobalt Metals from the Urban Mine Using Novel Sensors/Adsorbents Designated with Nanoscale Wagon-wheel-shaped Pores

Developing low-cost, efficient processes for recovering and recycling palladium, gold and cobalt metals from urban mine remains a significant challenge in industrialized countries. Here, the development of optical mesosensors/adsorbents (MSAs) for efficient recognition and selective recovery of Pd(II), Au(III), and Co(II) from urban mine was achieved. A simple, general method for preparing MSAs based on using high-order mesoporous monolithic scaffolds was described. Hierarchical cubic Ia3d wagon-wheel-shaped MSAs were fabricated by anchoring chelating agents (colorants) into three-dimensional pores and micrometric particle surfaces of the mesoporous monolithic scaffolds. Findings show, for the first time, evidence of controlled optical recognition of Pd(II), Au(III), and Co(II) ions and a highly selective system for recovery of Pd(II) ions (up to ~95%) in ores and industrial wastes. Furthermore, the controlled assessment processes described herein involve evaluation of intrinsic properties (e.g., visual signal change, long-term stability, adsorption efficiency, extraordinary sensitivity, selectivity, and reusability); thus, expensive, sophisticated instruments are not required. Results show evidence that MSAs will attract worldwide attention as a promising technological means of recovering and recycling palladium, gold and cobalt metals.

Because of the importance and extensive use of palladium, gold and cobalt metals in high-technology equipment, their recovery and recycling constitute an important industrial challenge. The metal recovery system described herein is a simple, low-cost means for the effective detection, removal, and recovery of these metals from the urban mine.

检测和钯的回收，从城市矿山黄金和钴金属使用标有纳米货车车轮形的孔隙新型传感器/吸附剂

Developing low-cost, efficient processes for recovering and recycling palladium, gold and cobalt metals from urban mine remains a significant challenge in ...

In Vitro Culture of Epicardial Cells From Mouse Embryonic Heart

During embryogenesis, the epicardial contribution to coronary vasculature development has been very well established. Cells derived from the epicardium differentiate into smooth muscle cells, fibroblasts and endothelial cells that contribute to the formation of coronary vessels. Here we have established an in vitro culture method for embryonic epicardial cells. Using genetic labelling, we have demonstrated that the majority of the migrating cells in our explant culture are of epicardial origin. Epicardial explant cells also retain the expression of epicardial markers (Wt1 and Tbx18). Furthermore, we provide evidence that epicardial explant cells undergo epithelial to mesenchymal transition (EMT), migrate and differentiate into smooth muscle cells after Transforming growth factor beta 1 (TGF-&#946;1) treatment in a manner indistinguishable from that of epicardial cells in vivo. In conclusion, we provide a novel method for the culture of embryonic epicardial cells, which will help to explore the role of specific genes in epicardial cell biology.

In Vitro Culture of Epicardial Cells From Mouse Embryonic Heart

The epicardium is an essential source of multipotent cardiovascular progenitor cells and paracrine factors that are required for cardiovascular development and regeneration. We describe here a method to culture mouse embryonic epicardial cells.

心外膜细胞小鼠胚胎心脏的体外培养

During embryogenesis, the epicardial contribution to coronary vasculature development has been very well established. Cells derived from the epicardium ...

Recombination Dynamics in Thin-film Photovoltaic Materials via Time-resolved Microwave Conductivity

A method for investigating recombination dynamics of photo-induced charge carriers in thin film semiconductors, specifically in photovoltaic materials such as organo-lead halide perovskites is presented. The perovskite film thickness and absorption coefficient are initially characterized by profilometry and UV-VIS absorption spectroscopy. Calibration of both laser power and cavity sensitivity is described in detail. A protocol for performing Flash-photolysis Time Resolved Microwave Conductivity (TRMC) experiments, a non-contact method of determining the conductivity of a material, is presented. A process for identifying the real and imaginary components of the complex conductivity by performing TRMC as a function of microwave frequency is given. Charge carrier dynamics are determined under different excitation regimes (including both power and wavelength). Techniques for distinguishing between direct and trap-mediated decay processes are presented and discussed. Results are modelled and interpreted with reference to a general kinetic model of photoinduced charge carriers in a semiconductor. The techniques described are applicable to a wide range of optoelectronic materials, including organic and inorganic photovoltaic materials, nanoparticles, and conducting/semiconducting thin films.

A Time Resolved Microwave Conductivity technique for investigating direct and trap-mediated recombination dynamics and determining carrier mobilities of thin film semiconductors is presented here.

通过时间分辨微波电导率重组动力学薄膜光伏材料

A method for investigating recombination dynamics of photo-induced charge carriers in thin film semiconductors, specifically in photovoltaic materials ...

Experimental Implementation of a New Composite Fabrication Method: Exposing Bare Fibers on the Composite Surface by the Soft Layer Method

The bipolar plate is a key component in proton exchange membrane fuel cells (PEMFCs) and vanadium redox flow batteries (VRFBs). It is a multi-functional component that should have high electrical conductivity, high mechanical properties, and high productivity.
In this regard, a carbon fiber/epoxy resin composite can be an ideal material to replace the conventional graphite bipolar plate, which often leads to the catastrophic failure of the entire system because of its inherent brittleness. Though the carbon/epoxy composite has high mechanical properties and is easy to manufacture, the electrical conductivity in the through-thickness direction is poor because of the resin-rich layer that forms on its surface. Therefore, an expanded graphite coating was adopted to solve the electrical conductivity issue. However, the expanded graphite coating not only increases the manufacturing costs but also has poor mechanical properties.
In this study, a method to expose fibers on the composite surface is demonstrated. There are currently many methods that can expose fibers by surface treatment after the fabrication of the composite. This new method, however, does not require surface treatment because the fibers are exposed during the manufacture of the composite. By exposing bare carbon fibers on the surface, the electrical conductivity and mechanical strength of the composite are increased drastically.

A protocol to expose bare fibers on the composite surface by eliminating resin rich area is presented. The fibers are exposed during fabrication of the composites, not by the post surface treatment. The exposed carbon composites exhibit high electrical conductivity in the through-thickness direction and high mechanical property.

一种新的复合制备方法的实验实现: 用软层法对复合材料表面裸露纤维进行曝光

The bipolar plate is a key component in proton exchange membrane fuel cells (PEMFCs) and vanadium redox flow batteries (VRFBs). It is a multi-functional ...

Fabrication of Ultra-thin Color Films with Highly Absorbing Media Using Oblique Angle Deposition

Ultra-thin film structures have been studied extensively for use as optical coatings, but performance and fabrication challenges remain.&#160; We present an advanced method for fabricating ultra-thin color films with improved characteristics. The proposed process addresses several fabrication issues, including large area processing. Specifically, the protocol describes a process for fabricating ultra-thin color films using an electron beam evaporator for oblique angle deposition of germanium (Ge) and gold (Au) on silicon (Si) substrates.&#160; Film porosity produced by the oblique angle deposition induces color changes in the ultra-thin film. The degree of color change depends on factors such as deposition angle and film thickness. Fabricated samples of the ultra-thin color films showed improved color tunability and color purity. In addition, the measured reflectance of the fabricated samples was converted into chromatic values and analyzed in terms of color. Our ultra-thin film fabricating method is expected to be used for various ultra-thin film applications such as flexible color electrodes, thin film solar cells, and optical filters. Also, the process developed here for analyzing the color of the fabricated samples is broadly useful for studying various color structures.

We present a detailed method for fabricating ultra-thin color films with improved characteristics for optical coatings. The oblique angle deposition technique using an electron beam evaporator allows improved color tunability and purity. Fabricated films of Ge and Au on Si substrates were analyzed by reflectance measurements and color information conversion.

用斜角沉积法制备高吸收介质的超薄彩色薄膜

Ultra-thin film structures have been studied extensively for use as optical coatings, but performance and fabrication challenges remain.&#160; We present ...

Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses

We demonstrate the use of two nuclear-based analytical methods that can follow the modifications of microstructural arrangement of iron-based metallic glasses (MGs). Despite their amorphous nature, the identification of hyperfine interactions unveils faint structural modifications. For this purpose, we have employed two techniques that utilize nuclear resonance among nuclear levels of a stable 57Fe isotope, namely M&#246;ssbauer spectrometry and nuclear forward scattering (NFS) of synchrotron radiation. The effects of heat treatment upon (Fe2.85Co1)77Mo8Cu1B14 MG are discussed using the results of ex situ and in situ experiments, respectively. As both methods are sensitive to hyperfine interactions, information on structural arrangement as well as on magnetic microstructure is readily available. M&#246;ssbauer spectrometry performed ex situ describes how the structural arrangement and magnetic microstructure appears at room temperature after the annealing under certain conditions (temperature, time), and thus this technique inspects steady states. On the other hand, NFS data are recorded in situ during dynamically changing temperature and NFS examines transient states. The use of both techniques provides complementary information. In general, they can be applied to any suitable system in which it is important to know its steady state but also transient states.

Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses

Here, we present a protocol to describe ex situ and in situ investigations of structural transformations in metallic glasses. We employed nuclear-based analytical methods which inspect hyperfine interactions. We demonstrate the applicability of M&#246;ssbauer spectrometry and nuclear forward scattering of synchrotron radiation during temperature-driven experiments.

结构转换的原位和原位研究方法: 金属玻璃结晶的实例

We demonstrate the use of two nuclear-based analytical methods that can follow the modifications of microstructural arrangement of iron-based metallic ...