我们非常感谢德国电信创新实验室的财政支持。

<html> 1。准备系统（图4） <ol><li>将激光二极管LD1和LD2在具体的安装，并与电流（LDC）和温度控制器（TEC）连接。打开设备上，并检查激光二极管的光频谱分析仪的功能。通常，围绕1550纳米的电信波长被使用。 </li><li>根据图4的设置的激光二极管连接到调制器（IM / PM和MZM1）。光纤连接器必须在使用前被清洁，以确保清洁的表面进行偶合。一个额外的电放大器，调制器连接一个电源（未示出）和信号从波形发生器（AWG）。确保在调制器的最大光学和电气输入功率不超过。每个调制器都配有一个偏振控制器。 </li></ol>/ files/ftp_upload/50468/50468fig4highres.jpg"SRC ="/ files/ftp_upload/50468/50468fig4.jpg"/&gt; 图4。的QLS由此强度和相位调制信号的存储是可能的实验装置 。蓝色标记的部分是只需要对相位调制信号的检测。该QLS过程发生在光纤。黄色标记部分定义了外差探测的频率梳的。 TEC:温度控制器，最不发达国家:激光二极管电流源，LD:激光二极管，IM:强度调制器，PM:相位调制器，PC:偏振控制器，特设工作组:任意波形发生器，MZM:马赫 - 曾德尔调制器，EDFA:掺铒光纤放大器C:循环，罗:本地振荡器，OSCI:示波器，OSA:光谱分析仪，PD:光电二极管，欧空局:电频谱分析仪。 <a href="https://jove.unicartagenaproxy.elogim.com/files/ftp_upload/50468/50468fig4highres.jpg" target="_blank">点击这里查看大图。</a> <ol开始="3"&gt; <li>连接光纤用的调制器，用于将数据信号。为相位调制信号，它必须是一个相位调制（PM）和用于强度调制的信号的强度调制器（IM）。通常，数据传输速率为实验是在Gbps的范围。在光纤的另一端与所述环行器（C）的端口2相连。在使用全波光纤在我们的实验有以下规格:L = 20公里处，Δf SBS = 10.2兆赫，F SBS = 10.852 GHz时， 第 P≈9.1 dBm的。 </li><li>与光学放大器（EDFA）连接振幅调制器，用于对频率梳生成（MZM1）。梳子具有以覆盖数据信号的带宽。在掺铒光纤放大器的输出端与环行器的端口1连接。 </li><li>对于相位调制的信号的检测中，参考源是必要的。连接的本地振荡器（LO）与环行器的输出为3〜50/50耦合在一起。对于int<html>密度调制信号，则不需要这部分。由于LO光纤激光器（Koheras）被使用。 </li><li>对于相位调制的信号:连接所述第三调制器（MZM2），用于提取延迟副本中的50/50耦合器的输出。对于强度调制信号，直接连接MZM2到循环的端口3。供给调制器的偏置电压（未示出）和一个矩形信号从波形发生器的CH1 Mkr1输出端口，用于提取。因此，原始数据信号，以及该矩形信号提取同步。 </li><li>有关检测和分析:MZM2后，再接上90/10耦合器。示波器与成色剂的90％端口连接，并且10％的部分是用光谱分析仪相连。 </li><li>编程用的数据包时，频率梳和矩形信号所需的信号的波形发生器。频率梳是由一个周期的sinc函数生成的。 </li></ol>e_title"&gt; 2。测量<ol><li>打开在波形发生器（AWG），用于对数据信号的输出。在电源改变偏置的调制器（IM / PM）和控制信号的质量在示波器上。调整最优质的转后的波形发生器关闭输出。调制器应围绕线性工作点被设置。典型值可以在结果一节中找到。 </li><li>调整频率梳与外差探测的品质。对于一个质量比较好的频率梳的例子示于图5。频率梳必须是平的， 例如，所有的频率分量具有相同的强度，且随时间保持稳定，以及足够宽，以覆盖整个光谱。此外，梳子的边缘应该是陡峭的， 比如有没有明显的频率分量与两侧的低强度。 </li><li>外差梳子检测I:连接MZM1用50/50的共同的输出upler。成色剂的其它端口都与一个光纤激光器（Koheras）作为本地振荡器相连。 </li><li>外差检测梳II:由于光电二极管和电频谱分析仪的带宽有限，第一耦合器的输出必须连接到光谱分析仪，以本机振荡器和所述信号之间的距离设置为8左右吉赫通过改变激光器的温度。 </li><li>外差检测梳三:调整后取出光谱分析仪和光电二极管和电频谱分析仪连接到的50/50耦合器的输出。调整梳调制器的偏置电压，以实现平坦的频率梳。完成后再次连接调制器的输出到光放大器（EDFA）。 </li><li>调整有关的布里渊频移与连续波信号的两个激光二极管（IM / PM和MZM1）之间的距离。因此，请确保波形发生器的输出是TUrned关闭。 </li><li>打开光放大器。看看光谱分析仪，并设置EDFA的输出功率，以低于受激布里渊散射的阈值。 </li><li>现在转向激光二极管的波长，它产生的数据信号（IM / PM）进入泵（MZM1）的增益区。如果波长是正确的信号会被放大。 </li><li>为优化改变数据信号的偏振，因此，强度为最大。 </li><li>打开波形发生器的两个输出（数据信号和梳状）。增加EDFA的输出功率。现在频率梳将等距抽取出来组成部分的频谱。示波器应显示由QLS产生不同的副本。对于失真减小略微移位的数据信号的波长，并改变它的偏振。 </li><li>以提取的副本中的一个使用波形发生器或外部源的标志信号中的一个可以制作的矩形脉冲。设置一个矩形脉冲，该数据包的长度。 </li><li>打开偏置MZM2并将其更改为工作点，其中提取出的信号被最大化，而所有其他副本会被抑制。现在的矩形脉冲转移到存储模式的期望版本。 </li><li>存储的数据模式可以保存在示波器和软件， 如地评估。 </li><li>为了强度的测量之间切换，相位调制的信号，需要从IM改变为强度调制信号PM对相位调制信号的调制器，用于将数据信号。另外，对于相位调制信号需要一个本地振荡器作为基准源，以根据图4被添加到安装程序。 </li></ol><img alt="图5" fo:content-width="5in" fo:src="/files/ftp_upload/50468/50468fig5highres.jpg" src="/ files/ftp_upload/50468/50468fig5.jpg"/&gt; 图5。几乎平坦的频率梳13家分公司 。通过外差检测，检测的梳子。用于检测本地振荡器经3dB耦合器结合的光信号，并用光电二极管检测到。频率梳测量和记录与一个电气频谱分析仪。本机振荡器的输出功率为6 dBm和梳子8 dBm的光功率。本机振荡器与光学梳之间的距离为9.8千兆赫。为了更好地了解频率轴是归它是大约193.5兆赫（1,550 nm）的梳子的中心频率。 <a href="https://jove.unicartagenaproxy.elogim.com/files/ftp_upload/50468/50468fig5highres.jpg" target="_blank">点击这里查看大图。</a>

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作者宣称，他们有没有竞争的财务权益。作者托马斯·施奈德，是德国电信股份公司的雇员。笔者斯特凡Preußler，收到由德国电信创新实验室提供的资金。

在实验过程中最关键的步骤是频率梳的调整， 即带宽度，平直度和位置在相对 ​​于在频域中的数据信号。根据在频域中的采样定理，信号失真是可以避免的，如果光学数据包的整个带宽被采样以一个理想的平面梳。因此，光学数据包的带宽定义的频率梳的最小带宽和在该带宽梳必须尽可能平坦。阿非理想频率梳将导致不规则的乘法与数据的频谱，因此，以不均匀的采样光谱。这将显著?...

在电信网络中的数据传输是光学的，因为只有光纤提供满足当今世界上传输的数据流量的能力。然而，在网络的每个节点的光信号已被转移到电域中，以便对其进行处理。处理后的信号被转换回用于进一步传输的光域。域之间的这种双转移是时间和功率消耗。为了使用数据的全光处理，使中间存储的问题已被解决。因此，大量的用于光信号的存储或缓冲的方法已被提出。最简单的方法是将信号发送到波导具有不同长度2的矩阵。然而，这些矩阵是笨重和存储时间不能被调谐，因为它是由波导长度预定义。 在"慢光"的方法依赖于一个tunab一个介质减慢光信号脉冲2的传播速度的群折射率乐变化。可用于这一目的3-6一些物理效应和材料的系统。然而，在这些方法中，信号可以通过很少的位长，这是迄今为止没有足够的用于光网络节点7,8减慢。 另一种方法是使用波长转换和色散可调谐延迟的产生。从而，输入信号的中心波长是通过非线性光学转换移位。此后，该信号被送入一个高度分散的纤维。在色散光纤群速度的差导致的延迟正比于在光纤中的波长偏移和群速度色散（GVD）的产物。与第二转换波长被移回原来的值。对于象四波混频或自相位莫波长偏移的技术dulation都可以使用。与转换和分散方法的储存时间长达243可调延迟，这对应于2400位的纳秒，据报道10。然而，在一般的波长转换和色散的方法需要用于产生一个大的波长偏移和/或大GVD特殊的组件和设置。此外，他们是最复杂的，耗电的延时方法2。 其他方法的光信号存储到一个材料系统的激励。甲探测光束，然后用来读出的信息。通常，这些系统不能在电信领域使用，因为它们需要超高或低温下11，不会与电信的带宽工作，或者需要比较复杂的设置和高功率12-14。 这里，我们显示如何的信号（时间 - 频率相干性）基本属性可被利用光学数据包的存储空间。正弦Ë无励磁材料体系的使用，我们已经调用的方法准光存储（QLS）15-17。该QLS是独立的调制，数据格式和数据包的数据传输速率，并可以为几千比特存储的光学数据包长度18。 的基本思想可以在图1中可以看出，这里矩形脉冲，如图所示。然而，本方法适用于每个脉冲形状和脉冲的包。唯一的限制是，该信号必须是有时限的。 <img alt="图1" fo:content-width="5in" fo:src="/files/ftp_upload/50468/50468fig1highres.jpg" src="/files/ftp_upload/50468/50468fig1.jpg" /> 图1。时频相干为强度调制信号23。在时域中的单个矩形信号（a）是由一个正弦函数在频率DOMA表示在（b）所示 。这里的归一化强度示出，因为它不可能测量用光学设备的字段。为矩形的信号序列的时域表示法表示在（c）所示 。这个序列仍具有相同的频谱形状。不过，它由正弦-信封（d）根据等距单一频率。时间轴被归到一个单一信号的一半，持续时间和频率轴的第一过零点，分别<a href="https://jove.unicartagenaproxy.elogim.com/files/ftp_upload/50468/50468fig1highres.jpg" target="_blank">点击这里查看大图。</a> 一个矩形脉冲在时域（ 图1a）具有"窦瓢虫"或正弦函数sin（PX）/ PX状的频谱（ 图1b），其中所述包络线下的所有频率都存在。矩形脉冲在时域（ 图1c）一列火车仍有一个SINC函数状的频谱（ 图1d）与带宽Δf。但由于周期性，而不是所有的频率都存在了。相反，该频谱由等距离的频率和频率间隔的倒数定义的脉冲ΔT = 1 /ΔV之间的时间间隔。 该QLS的基本思路是现在简单地提取等距离的频率对输入数据包的频谱。由于时间 - 频率相干性这导致分组的拷贝在时域中。与所需的延迟的复制可以通过时域开关被提取。 本实验的原理示于图2。有时间限制的输入信号乘以在频域中的频率梳。为乘法用于受激布里渊散射（SBS）的非线性效应。其结果是输入信号的等距离副本在日E时间域。之一的信号中提取与由矩形函数式开关。因此，在存储器的原理的输出输入脉冲的无失真的拷贝可以预期。 <img alt="图2" fo:content-width="5in" fo:src="/files/ftp_upload/50468/50468fig2highres.jpg" src="/files/ftp_upload/50468/50468fig2.jpg" /> 图2的准光存储15的基本概念。甲时间有限的输入信号（a）被乘以一个频率梳（b）在该频域，记有X，因为这导致了各个副本在时域信号（c）。从所生成的脉冲序列的拷贝（D）的一个与时域开关由一个矩形的读信号（e）萃取。该开关可以是一个调制器。其结果是存储的光信号的。在STORAGE时间由梳线和读信号之间的频率间隔定义。 <a href="https://jove.unicartagenaproxy.elogim.com/files/ftp_upload/50468/50468fig2highres.jpg" target="_blank">点击这里查看大图。</a> SBS本身是一种可以在低功率发生在标准单模光纤（SSMF）非线性效应。由此，该信号与由一个计数器传播泵波产生的光密度变化进行交互。如果信号波降档的频率，增益区形成在该信号会被放大。如果是向上移的信号将被衰减在相应的损失区域。泵和信号之间的频移是由声波，这取决于材料的性质来定义。 SBS对所提出的应用程序的最大优点是增益区的窄带宽Δf SBS。因此，实际上SBS形成了一个窄线宽光学滤波器。 T的窄带宽他获得区域依赖于有效长度的纤维和面积以及所使用的泵功率19。在SSMF自然全宽在SBS增益的半最大值（FWHM）的带宽大约为30兆赫。在特殊的波导，诸如全波光纤，并具有高的泵浦功率，带宽可以被降低到10 MHz 20。由于该滤波器的带宽的不同的副本都覆盖着一个信封。因此，QLS的最大存储时间成反比取决于SBS的带宽。 10 MHz的带宽将导致100 ns的最大存储时间。 <a href="https://jove.unicartagenaproxy.elogim.com/files/ftp_upload/50468/50468fig3highres.jpg" target="_blank">点击这里查看大图。</a> 对于非常高的比特速率传输的信息必须被编码成载波，而不是它的振幅的相位，因为这提供了很多优点。因此，违背脉冲，这些光网络的信号具有恒定振幅。 &lt;强&gt;图3示出了这样一个阶段中的时间（左）和频域（右）的调制信号。这个频谱进行采样的方式相同，幅度调制信号21。实际上矩形函数的强度和相位调制信号的频谱进行滤波，由于传输，从而限制了光谱。 <img alt="图3" fo:content-width="5in" fo:src="/files/ftp_upload/50468/50468fig3highres.jpg" src="/files/ftp_upload/50468/50468fig3.jpg" /> 图3。时频相干的相位调制21，在一个相位调制信号的载波的相位由具有要被发送的信号改变。如果每一个符号包括1比特，相位0和π之间变化，例如。该图的左侧示出了这种键控二进制相移所产生的时域表现（BPSK）信号。所得到的频域信号被显示在右侧。通过与图1比较，可以看出，相位调制信号的频谱是定性地相同的强度调制信号。因此，QLS可以以相同的方式被应用。

<table border="0" cellpadding="0" cellspacing="0" width="603">
	<tbody>
		<tr height="22">
			<td height="22" style="height:22px;width:111px;">Laser diode</td>
			<td style="width:147px;">3S Photonics</td>
			<td style="width:185px;">A1905LMI</td>
			<td style="width:160px;">2x</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:111px;">Laser Mount</td>
			<td style="width:147px;">Tektronix</td>
			<td style="width:185px;">LDH BFY-B2</td>
			<td style="width:160px;">2x</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:111px;">Temperature Controller</td>
			<td style="width:147px;">LightWave</td>
			<td style="width:185px;">LDT-5948</td>
			<td style="width:160px;">2x</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:111px;">Current Controller</td>
			<td style="width:147px;">LightWave</td>
			<td style="width:185px;">LDX-3220</td>
			<td style="width:160px;">2x</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:111px;">Optical amplifier</td>
			<td style="width:147px;">High-Wave</td>
			<td style="width:185px;">HWT-EDFA-B-30-1-FC/PC</td>
			<td style="width:160px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:111px;">Circulator</td>
			<td style="width:147px;">OFR</td>
			<td style="width:185px;">OCT-3-IR2</td>
			<td style="width:160px;"></td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:111px;">Waveform Generator</td>
			<td style="width:147px;">Tektronix</td>
			<td style="width:185px;">AWG7102</td>
			<td style="width:160px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:111px;">Fiber 20km</td>
			<td style="width:147px;">OFS</td>
			<td style="width:185px;">AllWave-ZWP G652C-D</td>
			<td style="width:160px;"></td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:111px;">Polarization Controller</td>
			<td style="width:147px;">Thorlabs</td>
			<td style="width:185px;">Fiber Pol. Contr. IPC030</td>
			<td style="width:160px;">2x</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:111px;">Modulator</td>
			<td style="width:147px;">Avanex</td>
			<td style="width:185px;">IM-10-P</td>
			<td style="width:160px;">Phase</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:111px;">Modulator</td>
			<td style="width:147px;">Avanex</td>
			<td style="width:185px;">SD20</td>
			<td style="width:160px;">Amplitude, extract</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:111px;">Modulator</td>
			<td style="width:147px;">Avanex</td>
			<td style="width:185px;">PowerBit F-10</td>
			<td style="width:160px;">Amplitude, data</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:111px;">Modulator</td>
			<td style="width:147px;">Covega</td>
			<td style="width:185px;">Mach10</td>
			<td style="width:160px;">Amplitude, comb</td>
		</tr>
		<tr height="64">
			<td height="64" style="height:64px;width:111px;">Optical Spectrum Analyzer</td>
			<td style="width:147px;">Yokogawa</td>
			<td style="width:185px;">AQ6370C</td>
			<td style="width:160px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:111px;">Oscilloscope</td>
			<td style="width:147px;">Agilent</td>
			<td style="width:185px;">DCA-J 86100C</td>
			<td style="width:160px;"></td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:111px;">Measurement Modul</td>
			<td style="width:147px;">Agilent</td>
			<td style="width:185px;">86106B</td>
			<td style="width:160px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:111px;">Fiber Laser</td>
			<td style="width:147px;">Koheras</td>
			<td style="width:185px;">Adjustik</td>
			<td style="width:160px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:111px;">Coupler</td>
			<td style="width:147px;">Newport</td>
			<td style="width:185px;">F-CPL-L22151-P</td>
			<td style="width:160px;">Ratio: 90/10</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:111px;">Coupler</td>
			<td style="width:147px;">Newport</td>
			<td style="width:185px;">F-CPL-L12155-P</td>
			<td style="width:160px;">Ratio: 50/50</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:111px;">Power supply</td>
			<td style="width:147px;">Zentro-elektrik</td>
			<td style="width:185px;">LD 2x15/1 GB</td>
			<td style="width:160px;"></td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:111px;">Electrical amplifier</td>
			<td style="width:147px;">SHF</td>
			<td style="width:185px;">826H</td>
			<td style="width:160px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:111px;">Supply port</td>
			<td style="width:147px;">SHF</td>
			<td style="width:185px;">B826</td>
			<td style="width:160px;"></td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:111px;">Electrical amplifier</td>
			<td style="width:147px;">Amplifier Research</td>
			<td style="width:185px;">10W1000</td>
			<td style="width:160px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:111px;">Photo diode</td>
			<td style="width:147px;">Newport</td>
			<td style="width:185px;">D-8ir</td>
			<td style="width:160px;"></td>
		</tr>
		<tr height="64">
			<td height="64" style="height:64px;width:111px;">Electrical spectrum analyzer</td>
			<td style="width:147px;">HP</td>
			<td style="width:185px;">8563E</td>
			<td style="width:160px;"></td>
		</tr>
	</tbody>
</table>

quasi-light storage for optical data packets

今天的通信是基于其传递的信息在世界各地的光纤网络，光纤数据包。目前，该信号的处理在电域中完成。直接存储在光域中将避免数据包的传送到电气和回在每个网络节点的光域，因此，增加速度，并可能减少通信的能量消耗。然而，光是由光子的光的速度在真空中传播的。因此，光存储是一个很大的挑战。存在着一些方法来减缓的光的速度，或者将其存储在介质中的激发。然而，这些方法不能用于在电信网络中使用的光学数据包的存储空间。在这里，我们将展示如何在时频相干，持有适用于各种信号，因此对于光学包为好，可以被利用来建立一个光存储器。之后我们将升评论的背景和显示在细节，并通过实施例中，如何将频率梳可用于其中进入存储器的光学数据包的复制。其中的一个时域的副本，然后从存储器中由时域开关萃取。我们将证明该方法对强度以及相位调制信号。

对于测量用的1 Gbps的数据速率10110101强度调制的数据图案被使用。黑线在图6中表示原始信号和彩色线表示实现了与QLS不同的存储时间。基准测量而不QLS和失活的开关输出。在理想条件下的储存时间高达100纳秒是可以实现的。其结果为一个相位调制信号的存储11001101数据图案，再以1 Gbps的数据速率可以看出，在图7中 ，用在左侧（黑色）的参考信号与SBS的不同提取拷贝基于QL...

Watch this Scientific Journal Video about Quasi-light Storage for Optical Data Packets at JoVE.com

Quasi-light Storage for Optical Data Packets

文章描述了一种方法来存储的光学数据包具有任意调制，波长，和数据传输速率。这些数据包是现代电信的基础。

准光存储光学数据包

Today's telecommunication is based on optical packets which transmit the information in optical fiber networks around the world. Currently, the processing ...

quasi-light-storage-for-optical-data-packets

Universidad de Cartagena UDEC

Research

Education

JoVE Core

JoVE Journal

Electrical Engineering

Engineering

Unit 1

Linear Time- Invariant Systems

SCIENTISTS IN ACTION

10.7K 次观看.  Hochschule für Telekommunikation, Leipzig. 文章描述了一种方法来存储的光学数据包具有任意调制，波长，和数据传输速率。这些数据包是现代电信的基础。 

视频: Quasi-light Storage for Optical Data Packets

Construction and Testing of Coin Cells of Lithium Ion Batteries

Rechargeable lithium ion batteries have wide applications in electronics, where customers always demand more capacity and longer lifetime. Lithium ion batteries have also been considered to be used in electric and hybrid vehicles1 or even electrical grid stabilization systems2. All these applications simulate a dramatic increase in the research and development of battery materials3-7, including new materials3,8, doping9, nanostructuring10-13, coatings or surface modifications14-17 and novel binders18. Consequently, an increasing number of physicists, chemists and materials scientists have recently ventured into this area. Coin cells are widely used in research laboratories to test new battery materials; even for the research and development that target large-scale and high-power applications, small coin cells are often used to test the capacities and rate capabilities of new materials in the initial stage. 
 In 2010, we started a National Science Foundation (NSF) sponsored research project to investigate the surface adsorption and disordering in battery materials (grant no. DMR-1006515). In the initial stage of this project, we have struggled to learn the techniques of assembling and testing coin cells, which cannot be achieved without numerous help of other researchers in other universities (through frequent calls, email exchanges and two site visits). Thus, we feel that it is beneficial to document, by both text and video, a protocol of assembling and testing a coin cell, which will help other new researchers in this field. This effort represents the "Broader Impact" activities of our NSF project, and it will also help to educate and inspire students.
In this video article, we document a protocol to assemble a CR2032 coin cell with a LiCoO2 working electrode, a Li counter electrode, and (the mostly commonly used) polyvinylidene fluoride (PVDF) binder. To ensure new learners to readily repeat the protocol, we keep the protocol as specific and explicit as we can. However, it is important to note that in specific research and development work, many parameters adopted here can be varied. First, one can make coin cells of different sizes and test the working electrode against a counter electrode other than Li. Second, the amounts of C black and binder added into the working electrodes are often varied to suit the particular purpose of research; for example, large amounts of C black or even inert powder were added to the working electrode to test the "intrinsic" performance of cathode materials14. Third, better binders (other than PVDF) have also developed and used18. Finally, other types of electrolytes (instead of LiPF6) can also be used; in fact, certain high-voltage electrode materials will require the uses of special electrolytes7.

A protocol to construct and test coin cells of lithium ion batteries is described. The specific procedures of making a working electrode, preparing a counter electrode, assembling a cell inside a glovebox and testing the cell are presented.

钮扣电池锂离子电池的建设和测试

Rechargeable lithium ion batteries have wide applications in electronics, where customers always demand more capacity and longer lifetime.  Lithium ion ...

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 ...

Optical Trapping of Nanoparticles

Optical trapping is a technique for immobilizing and manipulating small objects in a gentle way using light, and it has been widely applied in trapping and manipulating small biological particles. Ashkin and co-workers first demonstrated optical tweezers using a single focused beam1. The single beam trap can be described accurately using the perturbative gradient force formulation in the case of small Rayleigh regime particles1. In the perturbative regime, the optical power required for trapping a particle scales as the inverse fourth power of the particle size. High optical powers can damage dielectric particles and cause heating. For instance, trapped latex spheres of 109 nm in diameter were destroyed by a 15 mW beam in 25 sec1, which has serious implications for biological matter2,3.
A self-induced back-action (SIBA) optical trapping was proposed to trap 50 nm polystyrene spheres in the non-perturbative regime4. In a non-perturbative regime, even a small particle with little permittivity contrast to the background can influence significantly the ambient electromagnetic field and induce a large optical force. As a particle enters an illuminated aperture, light transmission increases dramatically because of dielectric loading. If the particle attempts to leave the aperture, decreased transmission causes a change in momentum outwards from the hole and, by Newton's Third Law, results in a force on the particle inwards into the hole, trapping the particle. The light transmission can be monitored; hence, the trap can become a sensor. The SIBA trapping technique can be further improved by using a double-nanohole structure.
The double-nanohole structure has been shown to give a strong local field enhancement5,6. Between the two sharp tips of the double-nanohole, a small particle can cause a large change in optical transmission, thereby inducing a large optical force. As a result, smaller nanoparticles can be trapped, such as 12 nm silicate spheres7 and 3.4 nm hydrodynamic radius bovine serum albumin proteins8. In this work, the experimental configuration used for nanoparticle trapping is outlined. First, we detail the assembly of the trapping setup which is based on a Thorlabs Optical Tweezer Kit. Next, we explain the nanofabrication procedure of the double-nanohole in a metal film, the fabrication of the microfluidic chamber and the sample preparation. Finally, we detail the data acquisition procedure and provide typical results for trapping 20 nm polystyrene nanospheres.

The following setup approach details low power optical trapping of dielectric nanoparticles using a double-nanohole in metal film.

纳米粒子的光学捕获

Optical trapping is a technique for immobilizing and manipulating small objects in a gentle way using light, and it has been widely applied in trapping ...

Bringing the Visible Universe into Focus with Robo-AO

The angular resolution of ground-based optical telescopes is limited by the degrading effects of the turbulent atmosphere. In the absence of an atmosphere, the angular resolution of a typical telescope is limited only by diffraction, i.e., the wavelength of interest, &lambda;, divided by the size of its primary mirror's aperture, D. For example, the Hubble Space Telescope (HST), with a 2.4-m primary mirror, has an angular resolution at visible wavelengths of ~0.04 arc seconds. The atmosphere is composed of air at slightly different temperatures, and therefore different indices of refraction, constantly mixing. Light waves are bent as they pass through the inhomogeneous atmosphere. When a telescope on the ground focuses these light waves, instantaneous images appear fragmented, changing as a function of time. As a result, long-exposure images acquired using ground-based telescopes - even telescopes with four times the diameter of HST - appear blurry and have an angular resolution of roughly 0.5 to 1.5 arc seconds at best.
Astronomical adaptive-optics systems compensate for the effects of atmospheric turbulence. First, the shape of the incoming non-planar wave is determined using measurements of a nearby bright star by a wavefront sensor. Next, an element in the optical system, such as a deformable mirror, is commanded to correct the shape of the incoming light wave. Additional corrections are made at a rate sufficient to keep up with the dynamically changing atmosphere through which the telescope looks, ultimately producing diffraction-limited images.
The fidelity of the wavefront sensor measurement is based upon how well the incoming light is spatially and temporally sampled1. Finer sampling requires brighter reference objects. While the brightest stars can serve as reference objects for imaging targets from several to tens of arc seconds away in the best conditions, most interesting astronomical targets do not have sufficiently bright stars nearby. One solution is to focus a high-power laser beam in the direction of the astronomical target to create an artificial reference of known shape, also known as a 'laser guide star'. The Robo-AO laser adaptive optics system2,3 employs a 10-W ultraviolet laser focused at a distance of 10 km to generate a laser guide star. Wavefront sensor measurements of the laser guide star drive the adaptive optics correction resulting in diffraction-limited images that have an angular resolution of ~0.1 arc seconds on a 1.5-m telescope.

Light from astronomical objects must travel through the earth's turbulent atmosphere before it can be imaged by ground-based telescopes. To enable direct imaging at maximum theoretical angular resolution, advanced techniques such as those employed by the Robo-AO adaptive-optics system must be used.

将成为关注的焦点，可见的宇宙ROBO-AO

The angular  resolution of ground-based optical telescopes is limited by the degrading  effects of the turbulent atmosphere. In the absence of an ...

The Generation of Higher-order Laguerre-Gauss Optical Beams for High-precision Interferometry

Thermal noise in high-reflectivity mirrors is a major impediment for several types of high-precision interferometric experiments that aim to reach the standard quantum limit or to cool mechanical systems to their quantum ground state. This is for example the case of future gravitational wave observatories, whose sensitivity to gravitational wave signals is expected to be limited in the most sensitive frequency band, by atomic vibration of their mirror masses. One promising approach being pursued to overcome this limitation is to employ higher-order Laguerre-Gauss (LG) optical beams in place of the conventionally used fundamental mode. Owing to their more homogeneous light intensity distribution these beams average more effectively over the thermally driven fluctuations of the mirror surface, which in turn reduces the uncertainty in the mirror position sensed by the laser light.
We demonstrate a promising method to generate higher-order LG beams by shaping a fundamental Gaussian beam with the help of diffractive optical elements. We show that with conventional sensing and control techniques that are known for stabilizing fundamental laser beams, higher-order LG modes can be purified and stabilized just as well at a comparably high level. A set of diagnostic tools allows us to control and tailor the properties of generated LG beams. This enabled us to produce an LG beam with the highest purity reported to date. The demonstrated compatibility of higher-order LG modes with standard interferometry techniques and with the use of standard spherical optics makes them an ideal candidate for application in a future generation of high-precision interferometry.

Large laser-interferometers are being constructed to create a new type of astronomy based on gravitational waves. Their sensitivities, as for many other high-precision experiments, are approaching fundamental noise limits such as the atomic vibration of their components. We are pioneering technologies to overcome these limits using novel laser beam shapes.

代高阶拉盖尔 - 高斯光束的高精度干涉

Thermal noise in high-reflectivity mirrors is a major impediment for several  types of high-precision interferometric experiments that aim to reach the  ...

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 ...

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.

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 ...

Compact Lens-less Digital Holographic Microscope for MEMS Inspection and Characterization

A micro-electro-mechanical-system (MEMS) is a widely used component in many industries, including energy, biotechnology, medical, communications, and automotive. However, effective inspection and characterization metrology systems are needed to ensure the functional reliability of MEMS. This study presents a system based on digital holography as a tool for MEMS metrology. Digital holography has gained increasing attention in the past 20 years. With the fast development and decreasing cost of sensor arrays, resolution of such systems has increased broadening potential applications. Thus, it has attracted attention from both research and industry sides as a potential reliable tool for industrial metrology. Indeed, by recording the interference pattern between an object beam (which contains sample height information) and a reference beam on a CCD camera, one can retrieve the quantitative phase information of an object. However, most of digital holographic systems are bulky and thus not easy to implement on industry production lines. The novelty of the system presented is that it is lens-less and thus very compact. In this study, it is shown that the Compact Digital Holographic Microscope (CDHM) can be used to evaluate several characteristics typically consider as criteria in MEMS inspections. The surface profiles of MEMS in both static and dynamic conditions are presented. Comparison with AFM is investigated to validate the accuracy of the CDHM.

We present a compact reflection digital holographic system (CDHM) for inspection and characterization of MEMS devices. A lens-less design using a diverging input wave providing natural geometrical magnification is demonstrated. Both static and dynamic studies are presented.

紧凑的镜头少数字全息显微镜的MEMS检测与表征

A micro-electro-mechanical-system (MEMS) is a widely used component in many industries, including energy, biotechnology, medical, communications, and ...

Data Acquisition Protocol for Determining Embedded Sensitivity Functions

The effectiveness of many structural health monitoring techniques depends on the placement of sensors and the location of input forces. Algorithms for determining optimal sensor and forcing locations typically require data, either simulated or measured, from the damaged structure. Embedded sensitivity functions provide an approach for determining the best available sensor location to detect damage with only data from the healthy structure. In this video and manuscript, the data acquisition procedure and best practices for determining the embedded sensitivity functions of a structure is presented. The frequency response functions used in the calculation of the embedded sensitivity functions are acquired using modal impact testing. Data is acquired and representative results are shown for a residential scale wind turbine blade. Strategies for evaluating the quality of the data being acquired are provided during the demonstration of the data acquisition process.

The data acquisition procedure for determining embedded sensitivity functions is described. Data is acquired and representative results are shown for a residential scale wind turbine blade.

数据采集​​协议确定嵌入式灵敏度功能

The effectiveness of many structural health monitoring techniques depends on the placement of sensors and the location of input forces. Algorithms for ...

Two-way Valorization of Blast Furnace Slag: Synthesis of Precipitated Calcium Carbonate and Zeolitic Heavy Metal Adsorbent

The aim of this work is to present a zero-waste process for storing CO2 in a stable and benign mineral form while producing zeolitic minerals with sufficient heavy metal adsorption capacity. To this end, blast furnace slag, a residue from iron-making, is utilized as the starting material. Calcium is selectively extracted from the slag by leaching with acetic acid (2 M CH3COOH) as the extraction agent. The filtered leachate is subsequently physico-chemically purified and then carbonated to form precipitated calcium carbonate (PCC) of high purity (&lt;2 wt% non-calcium impurities, according to ICP-MS analysis). Sodium hydroxide is added to neutralize the regenerated acetate. The morphological properties of the resulting calcitic PCC are tuned for its potential application as a filler in papermaking. In parallel, the residual solids from the extraction stage are subjected to hydrothermal conversion in a caustic solution (2 M NaOH) that leads to the predominant formation of a particular zeolitic mineral phase (detected by XRD), namely analcime (NaAlSi2O6&#8729;H2O). Based on its ability to adsorb Ni2+, as reported from batch adsorption experiments and ICP-OES analysis, this product can potentially be used in wastewater treatment or for environmental remediation applications.

A protocol for the parallel production of precipitated calcium carbonate and zeolitic material from blast furnace slag via mineral carbonation and alkaline hydrothermal conversion, respectively, is presented. The performance of the zeolitic material towards nickel adsorption is tested.

准光存储光学数据包

摘要

探索更多视频

此视频中的章节

钮扣电池锂离子电池的建设和测试

制造超材料使用光纤拉丝法

纳米粒子的光学捕获

将成为关注的焦点，可见的宇宙ROBO-AO

代高阶拉盖尔 - 高斯光束的高精度干涉

无序横向安德森本地化光聚合物光纤的制备和表征

写布拉格光栅在多核纤维

紧凑的镜头少数字全息显微镜的MEMS检测与表征

数据采集协议确定嵌入式灵敏度功能

高炉矿渣的双向稳定物价:沉淀碳酸钙和沸石重金属吸附剂的合成

准光存储光学数据包

摘要

探索更多视频

此视频中的章节

钮扣电池锂离子电池的建设和测试

制造超材料使用光纤拉丝法

纳米粒子的光学捕获

将成为关注的焦点，可见的宇宙ROBO-AO

代高阶拉盖尔 - 高斯光束的高精度干涉

无序横向安德森本地化光聚合物光纤的制备和表征

写布拉格光栅在多核纤维

紧凑的镜头少数字全息显微镜的MEMS检测与表征

数据采集​​协议确定嵌入式灵敏度功能

高炉矿渣的双向稳定物价:沉淀碳酸钙和沸石重金属吸附剂的合成

数据采集协议确定嵌入式灵敏度功能