IR 感谢列基金会的博士奖学金奖。

<ol>
	<li>Koski, K. J., Akhenblit, P., McKiernan, K., Yarger, J. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Non-invasive+determination+of+the+complete+elastic+moduli+of+spider+silks.">Non-invasive determination of the complete elastic moduli of spider silks.</a> Nat. Mater. 12 (3), 262-267 (2013).</li><li>Palombo, F., Madami, M., Stone, N., Fioretto, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanical+mapping+with+chemical+specificity+by+confocal+Brillouin+and+Raman+microscopy.">Mechanical mapping with chemical specificity by confocal Brillouin and Raman microscopy.</a> Analyst. 139 (4), 729-733 (2014).</li><li>Scarcelli, G., Yun, S. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vivo+Brillouin+optical+microscopy+of+the+human+eye.">In vivo Brillouin optical microscopy of the human eye.</a> Opt. Exp. 20 (8), 9197-9202 (2012).</li><li>Scarcelli, G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Noncontact+three-dimensional+mapping+of+intracellular+hydromechanical+properties+by+Brillouin+microscopy.">Noncontact three-dimensional mapping of intracellular hydromechanical properties by Brillouin microscopy.</a> Nat. Methods. 12 (12), 1132-1134 (2015).</li><li>Traverso, A. J., Thompson, J. V., Steelman, Z. A., Meng, Z., Scully, M. O., Yakovlev, V. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dual+Raman-Brillouin+microscope+for+chemical+and+mechanical+characterization+and+imaging.">Dual Raman-Brillouin microscope for chemical and mechanical characterization and imaging.</a> Anal. Chem. 87 (15), 7519-7523 (2015).</li><li>Antonacci, G., Foreman, M. R., Paterson, C., T&#246;r&#246;k, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spectral+broadening+in+Brillouin+imaging.">Spectral broadening in Brillouin imaging.</a> Appl. Phys. Lett. 103 (22), 221105 (2013).</li><li>Antonacci, G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantification+of+plaque+stiffness+by+Brillouin+microscopy+in+experimental+thin+cap+fibroatheroma.">Quantification of plaque stiffness by Brillouin microscopy in experimental thin cap fibroatheroma.</a> J. R. Soc. Interface. 12 (112), 20150483 (2015).</li><li>Grubbs, W. T., MacPhail, R. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High+resolution+stimulated+Brillouin+gain+spectrometer.">High resolution stimulated Brillouin gain spectrometer.</a> Rev. Sci. Instrum. 65 (1), 34-41 (1994).</li><li>Ballmann, C. W., Thompson, J. V., Traverso, A. J., Meng, Z., Scully, M. O., Yakovlev, V. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stimulated+Brillouin+scattering+microscopic+imaging.">Stimulated Brillouin scattering microscopic imaging.</a> Sci Rep. 5, 18139 (2015).</li><li>Remer, I., Bilenca, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Background-free+Brillouin+spectroscopy+in+scattering+media+at+780+nm+via+stimulated+Brillouin+scattering.">Background-free Brillouin spectroscopy in scattering media at 780 nm via stimulated Brillouin scattering.</a> Opt. Lett. 41 (5), 926-929 (2016).</li><li>Remer, I., Bilenca, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-speed+stimulated+Brillouin+scattering+spectroscopy+at+780+nm.">High-speed stimulated Brillouin scattering spectroscopy at 780 nm.</a> APL Photonics. 1 (6), 061301 (2016).</li><li>She, C. Y., Moosm&#252;ller, H., Herring, G. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Coherent+light+scattering+spectroscopy+for+supersonic+flow+measurements.">Coherent light scattering spectroscopy for supersonic flow measurements.</a> Appl. Phys. B-Lasers O. 46 (4), 283-297 (1988).</li><li>Fiore, A., Zhang, j., Peng Shao, ., Yun, S. H., Scarcelli, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-extinction+virtually+imaged+phased+array-based+Brillouin+spectroscopy+of+turbid+biological+media.">High-extinction virtually imaged phased array-based Brillouin spectroscopy of turbid biological media.</a> Appl. Phys. Lett. 108 (20), 203701 (2016).</li></ol>

作者没有什么可透露的。

该系统在图 1中所示, 设计为在 18 "x 24" 板上构建, 可以垂直安装在光学表上, 从而便于放置水样样品。因此, 重要的是要强烈收紧所有的光学和机械元件, 并确保泵和探头梁是共线和同心的各种元素之前, 照亮样品在离轴几何。
观察受激布里渊增益信号的困难可能是由于过多的杂散泵反射, 掩盖了水样样品的弱布里渊增益 (~ 10-6)。为了解决这些可能遇到的困难, 首先确保将分室定位在探头和泵浦聚焦透镜的关节焦点 (l3和 l4, 分别)。然后, 稍微关闭在铷细胞之前放置的虹膜 (I) 并且/或者稍微翻译一下泵浦光束 (M6) 的折叠镜, 以进一步消除对杂散泵反射的检测。请注意, 这些过程也将减少布里渊信号, 但可能提供一个更好的出发点, 以检测受激布里渊增益信号在水中。如果信号仍未检测到, 使用甲醇或二硫化碳, 其布里渊增益明显强于水8,10。另外, 对于 non-turbid 样品的测量, 可以使用较厚的玻璃腔 (十倍于3/l4的共焦参数), 大大减少了对杂散泵反射的检测。
在协议中, 我们描述了 2 GHz 的受激布里渊增益谱的高速测量。要将测量扩展到较大的带宽 (例如, 在与 #62 分离的多个布里渊频移的示例中), 必须在扩展频率失谐的情况下生成探针调制电流的校准曲线泵和探头激光器的范围。刻意, 该曲线应修正为激光频率扫频与调制电流的小非线性。另外, 可以将泵探头频率失谐的快速监测方案集成到光谱仪中, 以取代微波频率计数器 (FC)。
这里所提出的设置所测量的布里渊频移和线宽可以转换为一个已知密度和样本4的折射率的 GHz 频率的材料复杂纵向模数。在自发布里渊光谱学中, 材料刚度张量的其他元素 (例如, 剪切模量) 可以利用 SBS 光谱来探测不同天使的散射光和泵浦光的偏振态。布里渊频谱, 然后表现出较低的信噪比 (由于泵和探头光束在样本10,11,12) 和更小的布里渊频率更小的交叉效率转移和线 (由于减少的交叉角) 比那些在几乎背向散射几何获得。因此, 需要使用较长的测量时间和较窄线的激光器。
为了测量 non-turbid 样品中的布里渊光谱, 我们目前的 SBS 光谱仪提供的采集时间与 VIPA 光谱仪4获得的相媲美, 并且比现有的100倍的速度快。continuous-wave 受激布里渊散射光谱仪 (具有类似的布里渊移位灵敏度)9,10,11。对于混浊介质中的布里渊测量, 我们的仪器能够在短至100毫秒的时间内获得2.25 散射事件的混浊样品的布里渊光谱, 它比 VIPA 光谱仪使用的多法布里-Perot-based 的速度快3倍。0.13-1.33 散射事件的混浊样品中的瑞利抑制滤波器13。不像 VIPA 光谱仪, SBS 光谱仪不需要任何专业的瑞利拒绝过滤器, 并天生提供优异的对比度, 即使在混浊样品与强弹性散射10,11。
目前的 SBS 光谱仪尚未达到射噪极限。光谱仪噪声主要由 non-turbid 样品中的强度噪声和混浊介质中的电噪声11控制。因此, SBG 信号的信噪比 (即捕获时间) 是有限的。为了克服这一局限性, 在不降低布里渊移位灵敏度11的情况下, 可以使用在锁定检测之前的低噪声电放大器来进一步减少散射材料中 SBG 谱的捕获时间。此外, 在真正的后向散射几何中, 使用具有较高抑制杂散泵光的射噪限制激光光源, 将能最佳地提高光谱仪的信噪比, 使记录 SBG 谱的时间更短高布里渊移位灵敏度11。

自发布里渊光谱学近年来已经建立, 作为一种有价值的方法, 用于机械分析软材料, 如液体, 真实组织, 组织幻影和生物细胞1,2, 3,4,5,6,7。在这种方法中, 一个单一的激光照射的样品和光, 是弹性散射从自发的热声波在介质中收集的分光计, 提供有用的信息的粘弹性性质的样品。自发布里渊频谱包括两个布里渊峰在声波斯托克斯和反斯托克斯共振的材料, 和瑞利峰在照明激光频率 (由于弹性散射光)。对于布里渊散射几何, 布里渊频率由几个 GHz 从照明激光频率转移, 有数百兆赫的频谱宽度。
当扫描法布里-珀罗光谱仪已 systems-of-choice 获得自发布里渊光谱在软物质1,2, 最近的技术进步在几乎成像相阵列 (VIPA)光谱仪已启用显着更快 (秒) 布里渊测量与适当的频谱分辨率 (子 GHz)3,4,5,6,7。在本协议中, 我们提出了一个不同的, 高速, 高光谱分辨率, 精确的布里渊光谱仪的基础上检测 continuous-wave-受激-布里渊散射 (CW-SBS) 光从 non-turbid 和混浊样品在一个几乎反散射几何。
在 cw-SBS 光谱中, continuous-wave (cw) 泵和探针激光器, 在频率上略谐, 在样品中重叠以刺激声波。当泵与探头横梁的频率差与材料的特定声学共振相匹配时, 探头信号的放大或 deamplification 分别由受激布里渊增益或损耗 (SBG/SBL) 过程提供;否则, 没有 SBS (de) 放大发生8,9,10,11。因此, SBG (SBL) 频谱可以通过扫描在材料布里渊共振的激光之间的频率差和检测增加 (减少), 或增益 (损失), 在探针强度由于 SBS。与自发布里渊散射不同的是, 弹性散射背景在 SBS 中是固有的, 在混浊和 non-turbid 样品中都能得到优异的布里渊对比度, 而不需要 VIPA 的瑞利滤波器。光谱仪10,11,13。
CW-SBS 光谱仪的主要组成部分是泵浦和探针激光器以及受激布里渊增益/损耗检测器。对于高光谱分辨率, 高速 CW-SBS 光谱学, 激光器需要单 (#60; 10 MHz 线宽) 与足够宽波长调谐 (20-30 ghz) 和扫描率 (和 #62; 200 GHz/秒), 长期频率稳定 (和 #60; 50MHz/小时) 和低强度噪音。此外, 该泵 (探头) 横梁上需要具有几百 (数十) 兆瓦的功率的线性偏振和衍射有限激光束。最后, 应设计受激布里渊增益/损耗检测器, 以可靠地检测弱向后受激布里渊增益/损耗 (SBG/SBL) (10-5 -10-6) 的软物质。为了满足这些需求, 我们选择了分布式反馈 (DFB) 二极管激光器耦合到极化维护光纤和受激布里渊增益/损耗探测器结合 ultra-narrowband 原子蒸气缺口滤波器single-modulation 锁相放大器, 如图 1所示。此检测方案使 SBG 信号的强度加倍, 同时显著降低探头强度中的噪声, 而所需的 SBG 信号嵌入11。请注意, 在我们的 SBS 光谱仪中使用的原子气陷式过滤器的作用是显著减少不需要的杂散泵反射的检测, 而不是减少在 VIPA 光谱仪中检测到的弹性散射背景自发瑞利和布里渊散射光。使用下面详述的协议, 可以构造一个 CW-SBS 光谱仪, 能够获得水和组织幽灵的透射谱, 其 SBG 水平低至 10-6 , #60; 35 MHz 布里渊移位测量精度和在100毫秒以内。
<img alt="Figure 1" src="/files/ftp_upload/55527/55527fig1.jpg"> 
图 1: 连续波受激布里渊散射 (CW-SBS) 光谱仪.两个 continuous-wave 泵和探针二极管激光器 (DL), 频率谐周围的布里渊转移的样本, 是耦合成极化维护单模光纤与直 c1和 c2, 分别。测量泵探头的频率差, 通过检测从泵剥离的光束和使用一组光纤分配器 (FS)、快速光电探测器 (平板显示器) 和频率计数器 (FC) 的探测激光器之间的跳动频率。S 极化探头光束 (浅红色), 扩展使用 Keplerian 光束膨胀器 (l1和 l2), 是右圆极化的四分之一波板 (λ1/4), 并专注于样本 (S) 由一个消色差透镜 (l3)。为有效的 SBS 相互作用和光隔离, 泵梁 (深红色), 扩大使用 Keplerian 扩束器 (l5和 l6), 是第一个 P 极化使用波板λ2/4), 然后通过极化传输光束分配器 (PBS), 并最终留下圆极化的四分之一波板 (λ2/4), 并专注于样品与无色透镜 (l4; 与 l3相同)。请注意, 泵和探头横梁几乎 counter-propagate 在样品中, 并使用 S 型偏振器 (p) 来防止 p 极化泵光束 (来自λ1/4) 进入探针激光器。对于锁定检测, 泵浦光束在fm 上正弦调制, 并带有声光调制器 (AOM)。SBG 信号, 表现为强度变化在频率fm (参见插页), 被解调用由大面积光电二极管 (PD) 检测后的锁定放大器。为了显著消除光电二极管中的杂散泵反射, 在泵浦波长周围使用窄带布拉格滤波器 (BF) 和原子陷波器 (85RB), 同时用遮光虹膜 (I)。数据通过连接到个人电脑 (PC) 的数据采集卡进行记录, 以进一步分析布里渊频谱。所有折叠镜 (m1-m6) 用于将光谱仪放在一个 18 "×24" 板上, 垂直安装在光学工作台上, 以方便水样样品的放置。<a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/55527/55527fig1large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Probe diode laser head and controller</td>
			<td>Toptica Photonics</td>
			<td>SYST DL-100-DFB</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>Pump amplified diode laser and controller</td>
			<td>Toptica Photonics</td>
			<td>SYST TA-pro-DFB</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>FC/APC fiber dock</td>
			<td>Toptica Photonics</td>
			<td>FiberDock&#160;</td>
			<td>Quantity: 3</td>
		</tr>
		<tr>
			<td>High power single mode polarization maintaining FC/APC fiber patchcord</td>
			<td>Toptica Photonics</td>
			<td>OE-000796</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>FC/APC fiber collimation with adjustable collimation optics</td>
			<td>Toptica Photonics</td>
			<td>FiberOut</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>FC/APC fiber fixed collimator</td>
			<td>OZ Optics</td>
			<td>HPUCO-33A-780-P-6.1-AS</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>Single mode polarization maintaining fiber splitter 33:67</td>
			<td>OZ Optics</td>
			<td>FOBS-12P-111-4/125-PPP-780-67/33-40-3A3A3A-3-1</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>Single mode polarization maintaining fiber splitter 50:50</td>
			<td>OZ Optics</td>
			<td>FOBS-12P-111-4/125-PPP-780-50/50-40-3S3A3A-3-1</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>f=25 mm, &#216;1/2&#34; Achromatic Doublet, SM05-Threaded Mount, ARC: 650-1050 nm</td>
			<td>Thorlabs</td>
			<td>AC127-025-B-ML</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>f=30 mm, &#216;1&#34; Achromatic Doublet, SM1-Threaded Mount, ARC: 650-1050 nm</td>
			<td>Thorlabs</td>
			<td>AC254-30-B-ML</td>
			<td>Quantity: 2</td>
		</tr>
		<tr>
			<td>f=50 mm, &#216;1&#34; Achromatic Doublet, SM1-Threaded Mount, ARC: 650-1050 nm</td>
			<td>Thorlabs</td>
			<td>AC254-50-B-ML</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>f=100 mm, &#216;1&#34; Achromatic Doublet, SM1-Threaded Mount, ARC: 650-1050 nm</td>
			<td>Thorlabs</td>
			<td>
AC254-100-B-ML</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>f=200 mm, &#216;1&#34; Achromatic Doublet, SM1-Threaded Mount, ARC: 650-1050 nm</td>
			<td>Thorlabs</td>
			<td>
AC254-200-B-ML</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>&#216;1/2&#34; Broadband Dielectric Mirror, 750-1100 nm</td>
			<td>Thorlabs</td>
			<td>
BB05-E03</td>
			<td>Quantity: 4</td>
		</tr>
		<tr>
			<td>&#216;1&#34; Broadband Dielectric Mirror, 750-1100 nm</td>
			<td>Thorlabs</td>
			<td>
BB1-E03</td>
			<td>Quantity: 2</td>
		</tr>
		<tr>
			<td>1&#34; Polarizing beamsplitter cube, 780 nm</td>
			<td>Thorlabs</td>
			<td>
PBS25-780</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>&#216;1&#34; Linear polarizer with N-BK7 protective windows, 600-1100 nm</td>
			<td>Thorlabs</td>
			<td>
LPNIRE100-B</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>Shearing Interferometer with a 1-3 mm Beam Diameter Shear Plate</td>
			<td>Thorlabs</td>
			<td>SI035</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>6-Axis Locking kinematic optic mount</td>
			<td>Thorlabs</td>
			<td>
K6XS</td>
			<td>Quantity: 4</td>
		</tr>
		<tr>
			<td>Compact five-axis platform</td>
			<td>Thorlabs</td>
			<td>
PY005</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>Pedestal mounting adapter for 5-axis platform</td>
			<td>Thorlabs</td>
			<td>
PY005A2</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>Polaris low drift &#216;1/2&#34; kinematic mirror mount, 3 adjusters</td>
			<td>Thorlabs</td>
			<td>
POLARIS-K05</td>
			<td>Quantity: 4</td>
		</tr>
		<tr>
			<td>Lens mount for &#216;1&#34; optics</td>
			<td>Thorlabs</td>
			<td>
LMR1</td>
			<td>Quantity: 5</td>
		</tr>
		<tr>
			<td>Adapter with external SM1 threads and Internal SM05 threads, 0.40&#34; thick</td>
			<td>Thorlabs</td>
			<td>
SM1A6T</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>Rotation mount for &#216;1&#34; optics</td>
			<td>Thorlabs</td>
			<td>
RSP1</td>
			<td>Quantity: 2</td>
		</tr>
		<tr>
			<td>1&#34; Kinematic prism mount</td>
			<td>Thorlabs</td>
			<td>
KM100PM</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>Graduated ring-activated SM1 iris diaphragm</td>
			<td>Thorlabs</td>
			<td>
SM1D12C</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>Post-mounted iris diaphragm, &#216;12.0 mm max aperture</td>
			<td>Thorlabs</td>
			<td>ID12</td>
			<td>Quantity: 2</td>
		</tr>
		<tr>
			<td>1/2&#34; translation stage with standard micrometer</td>
			<td>Thorlabs</td>
			<td>MT1</td>
			<td>Quantity: 3</td>
		</tr>
		<tr>
			<td>&#216;1&#34; Pedestal pillar post, 8-32 taps, L = 1&#34;</td>
			<td>Thorlabs</td>
			<td>RS1P8E</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>&#216;1&#34; Pedestal pillar post, 8-32 taps, L = 1.5&#34;</td>
			<td>Thorlabs</td>
			<td>RS1.5P8E</td>
			<td>Quantity: 2</td>
		</tr>
		<tr>
			<td>&#216;1&#34; Pedestal pillar post, 8-32 taps, L = 2&#34;</td>
			<td>Thorlabs</td>
			<td>RS2P8E</td>
			<td>Quantity: 4</td>
		</tr>
		<tr>
			<td>&#216;1&#34; Pedestal pillar post, 8-32 taps, L = 2.5&#34;</td>
			<td>Thorlabs</td>
			<td>RS2.5P8E</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>&#216;1&#34; Pedestal pillar post, 8-32 taps, L = 3&#34;</td>
			<td>Thorlabs</td>
			<td>RS3P8E</td>
			<td>Quantity: 4</td>
		</tr>
		<tr>
			<td>Short clamping fork</td>
			<td>Thorlabs</td>
			<td>CF125</td>
			<td>Quantity: 12</td>
		</tr>
		<tr>
			<td>Mounting base</td>
			<td>Thorlabs</td>
			<td>BA1S</td>
			<td>Quantity: 8</td>
		</tr>
		<tr>
			<td>Large V-Clamp with PM4 Clamping Arm, 2.5&#34; Long, Imperial</td>
			<td>Thorlabs</td>
			<td>VC3C</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>&#216;1/2&#34; Post holder, spring-loaded hex-locking thumbscrew, L = 1&#34;</td>
			<td>Thorlabs</td>
			<td>PH1</td>
			<td>Quantity: 2</td>
		</tr>
		<tr>
			<td>&#216;1/2&#34; Post holder, spring-loaded hex-locking thumbscrew, L = 1.5&#34;</td>
			<td>Thorlabs</td>
			<td>PH1.5</td>
			<td>Quantity: 2</td>
		</tr>
		<tr>
			<td>&#216;1/2&#34; Post holder, spring-loaded hex-locking thumbscrew, L = 2&#34;</td>
			<td>Thorlabs</td>
			<td>PH2</td>
			<td>Quantity: 6</td>
		</tr>
		<tr>
			<td>&#216;1/2&#34; Optical post, SS, 8-32 setscrew, 1/4&#34;-20 tap, L = 1&#34;</td>
			<td>Thorlabs</td>
			<td>TR1</td>
			<td>Quantity: 2</td>
		</tr>
		<tr>
			<td>&#216;1/2&#34; Optical post, SS, 8-32 setscrew, 1/4&#34;-20 tap, L = 1.5&#34;</td>
			<td>Thorlabs</td>
			<td>TR1.5</td>
			<td>Quantity: 2</td>
		</tr>
		<tr>
			<td>&#216;1/2&#34; Optical post, SS, 8-32 setscrew, 1/4&#34;-20 tap, L = 2&#34;</td>
			<td>Thorlabs</td>
			<td>TR2</td>
			<td>Quantity: 6</td>
		</tr>
		<tr>
			<td>Aluminum breadboard 18&#34; x 24&#34; x 1/2&#34;, 1/4&#34;-20 taps</td>
			<td>Thorlabs</td>
			<td>MB1824</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>12&#34; Vertical bracket for breadboards, 1/4&#34;-20 holes, 1 piece</td>
			<td>Thorlabs</td>
			<td>VB01</td>
			<td>Quantity: 2</td>
		</tr>
		<tr>
			<td>Si photodiode, 40 ns Rise time, 400 - 1100 nm, 10 mm x 10 mm active area</td>
			<td>Thorlabs</td>
			<td>
FDS1010</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>Waveplate, zero order, 1/4 wave 780nm</td>
			<td>Tower Optics</td>
			<td>Z-17.5-A-.250-B-780</td>
			<td>Quantity: 2</td>
		</tr>
		<tr>
			<td>Waveplate, zero order, 1/2 wave 780nm</td>
			<td>Tower Optics</td>
			<td>Z-17.5-A-.500-B-780</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>Fiber coupled ultra high speed photodetector</td>
			<td>Newport</td>
			<td>1434</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>Gimbal optical miror mount</td>
			<td>Newport</td>
			<td>U100-G2H ULTIMA</td>
			<td>Quantity: 3</td>
		</tr>
		<tr>
			<td>linear stage with 25 mm travel range</td>
			<td>Newport</td>
			<td>&#160;M-423&#160;</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>Lockable differential micrometer, 25 mm coarse, 0.2 mm fine,11 lb. load</td>
			<td>Newport</td>
			<td>&#160;DM-25L</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>XYZ Motor linear stage</td>
			<td>Applied Scientific Instrumentation</td>
			<td>LS-50</td>
			<td>Quantity: 3</td>
		</tr>
		<tr>
			<td>Stage controller</td>
			<td>Applied Scientific Instrumentation</td>
			<td>MS-2000</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>Sample holder</td>
			<td>Home made</td>
			<td>Custom</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>Rubidium 85 Fused Silica spectroscopy cell with flat AR-coated windows, 150 mm length, 25mm diameter</td>
			<td>Photonics Technologies</td>
			<td>SC-RB85-25x150-Q-AR</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>Thermally conductive pad 300 mm x 300 mm</td>
			<td>BERGQUIST</td>
			<td>Q3AC 300MMX300MM SHEET</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>Heat tape 0.15 mm x 2.5&#160; mm x 5 m, 4.29&#160; W/m</td>
			<td>KANTHAL</td>
			<td>8908271</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>Polytetrafluoroethylene tape 1/2&#39;&#39; x 12 m</td>
			<td>Teflon tape</td>
			<td>R.G.D</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>Reflecting Bragg grating bandpass filter</td>
			<td>OptiGrate</td>
			<td>SPC-780</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>High frequncy aousto optic modulator</td>
			<td>Gooch and Housego</td>
			<td>15210</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>Aousto optic modulator RF driver, frequncy: 210 MHz&#160;</td>
			<td>Gooch and Housego</td>
			<td>MHP210-1ADS2-A1</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>High frequncy lock-in amplifier&#160;</td>
			<td>Stanford Research Systems</td>
			<td>SR844</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>Frequency counter</td>
			<td>Phase Matrix</td>
			<td>EIP 578B</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>Arbitrary function Generator</td>
			<td>Tektronix</td>
			<td>AFG2021</td>
			<td>Quantity: 2</td>
		</tr>
		<tr>
			<td>Data acquisition (DAQ) module</td>
			<td>National Instruments</td>
			<td>NI USB-6212 BNC</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>Data acquisition (DAQ) software&#160;</td>
			<td>National Instruments</td>
			<td>LabVIEW 2014</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>Regulated DC power supply&#160; dual 0-30V 5A</td>
			<td>MEILI</td>
			<td>MCH-305D-ii</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>Thermocouple</td>
			<td>MRC</td>
			<td>TP-01</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>Thermometer</td>
			<td>MRC</td>
			<td>TM-5007</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>Coaxial low pass filter DC-1.9 MHz</td>
			<td>Mini Circuits</td>
			<td>BLP-1.9+</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>20% lipid-emulsion</td>
			<td>Sigma-Aldrich</td>
			<td>I141-100ml</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>24x40 mm cover glass thick:3 #</td>
			<td>Menzel Glaser</td>
			<td>150285</td>
			<td>Quantity: 1</td>
		</tr>
		<tr>
			<td>Computational software&#160;</td>
			<td>MathWorks</td>
			<td>MATLAB 2015a</td>
			<td></td>
		</tr>
	</tbody>
</table>

high-speed continuous-wave stimulated brillouin scattering spectrometer for material analysis

近年来, 自发布里渊光谱仪在非接触性分析软物质, 如水溶液和生物材料等方面的使用有了显著增加, 获得了快速的采集时间。在这里, 我们讨论的组装和运行的布里渊光谱仪, 使用受激布里渊散射 (SBS) 测量的受激布里渊增益 (SBG) 光谱的水和脂 emulsion-based 组织样样品在传输模式与 &lt; 10 兆赫光谱分辨率和 &lt; 35 MHz 布里渊位移测量精度在 &lt; 100 ms. 分光计由两个近拉曼光 continuous-wave (CW) 窄线宽激光器组成, 其频率失谐的 780 nm 扫描通过材料布里渊移位。通过采用 ultra-narrowband 热 rubidium-85 气陷式过滤器和相敏探测器, 与现有的 CW-SBS 光谱仪相比, SBG 信号的信噪比得到显著提高。这种改进使测量的 SBG 频谱高达100倍的更快的采集时间, 从而促进高光谱分辨率和高精度的布里渊分析软材料的高速。

图 2b和3b显示了蒸馏水和脂质乳胶组织幻像样本的典型点 SBG 谱 (2.25 散射事件和 45 cm-1的衰减系数) 分别在 10 ms 和100毫秒内测量。为了比较, 我们测量了十年代的 SBG 谱, 如图 2a和3a所示。在这些测量中, rubidium-85 蒸气细胞被加热到90° c 衰减杂散泵反射通过 ~ 104和传输和 #62; 95% 探针光;在 h11上保持稳定的级别。此外, 空间分辨率, 这里定义为横向全角在 half-maximum 的 SBS 强度检测到的焦点, 估计是大约8µm10。在水和组织幽灵中获得的快速获得的光谱的平均布里渊位移分别为 5.08 ghz 和 5.11 ghz。这些布里渊移位估计值与十年代记录的频谱和以前发布的含水样品的布里渊数据9、10、11的计算结果相比较。图中的插图显示了从200连续的 SBG 谱测量中检索到的布里渊移位估计的直方图。根据所观测到的布里渊移位分布的高斯分布的标准差, 对所得布里渊移位的精度进行了评估。在水和组织幻像样本中获得了 8.5 mhz 和 33 mhz 的标准偏差, 这代表了检测材料力学中细微变化的高测量精度。虽然这里使用的泵功率水平很高 (〜 250-270 兆瓦), 由于水的吸收在 780 nm 估计是和 #60; 0.53 K, 因此可以忽略在这项工作中使用的水样本10。此外, 在120s 连续暴露于这些功率水平时, 观察到水和脂乳剂样品的 SBG 谱的短期不稳定性。
<img alt="Figure 2" src="/files/ftp_upload/55527/55527fig2.jpg"> 
图 2: 受激布里渊增益 (SBG) 水的光谱.在 (a) 十年代获得的水的代表性 SBG 谱和 (b) 10 毫秒点和实线分别代表测量值和洛伦兹拟合。镶嵌显示了相应的直方图的布里渊漂移估计水。<a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/55527/55527fig2large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 3" src="/files/ftp_upload/55527/55527fig3.jpg"> 
图 3: 组织幻影的受激布里渊增益 (SBG) 谱.具有代表性的 SBG 谱的脂乳剂组织幽灵 (2.25 散射事件和衰减系数为45厘米-1) 获得的 (a) 十年代和 (b) 100 毫秒点和实线表示测量值和洛伦兹适合, 分别。镶嵌显示了组织幻像的布里渊移位估计的相应直方图。<a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/55527/55527fig3large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>

Watch this Scientific Journal Video about High-speed Continuous-wave Stimulated Brillouin Scattering Spectrometer for Material Analysis at JoVE.com

High-speed Continuous-wave Stimulated Brillouin Scattering Spectrometer for Material Analysis

我们描述了一个快速 continuous-wave-受激-布里渊散射 (CW-SBS) 光谱仪的构造。该光谱仪采用单二极管激光器和原子蒸气缺口滤波器来获得高光谱分辨率的混浊/non-turbid 样品的透射光谱, 其速度比现有的 CW-SBS 光谱仪快100倍。这种改进可以实现高速布里渊材料分析。

用于材料分析的高速连续波受激布里渊散射光谱仪

Recent years have witnessed a significant increase in the use of spontaneous Brillouin spectrometers for non-contact analysis of soft matter, such as ...

high-speed-continuous-wave-stimulated-brillouin-scattering

Nanyang Technological University

Research

JoVE Journal

Engineering

10.1K 次观看.  Ben-Gurion University of the Negev. 我们描述了一个快速 continuous-wave-受激-布里渊散射 (CW-SBS) 光谱仪的构造。该光谱仪采用单二极管激光器和原子蒸气缺口滤波器来获得高光谱分辨率的混浊/non-turbid 样品的透射光谱, 其速度比现有的 CW-SBS 光谱仪快100倍。这种改进可以实现高速布里渊材料分析。 

视频: High-speed Continuous-wave Stimulated Brillouin Scattering Spectrometer for Material Analysis

Measuring Spatially- and Directionally-varying Light Scattering from Biological Material

Light interacts with an organism's integument on a variety of spatial scales. For example in an iridescent bird: nano-scale structures produce color; the milli-scale structure of barbs and barbules largely determines the directional pattern of reflected light; and through the macro-scale spatial structure of overlapping, curved feathers, these directional effects create the visual texture. Milli-scale and macro-scale effects determine where on the organism's body, and from what viewpoints and under what illumination, the iridescent colors are seen. Thus, the highly directional flash of brilliant color from the iridescent throat of a hummingbird is inadequately explained by its nano-scale structure alone and questions remain. From a given observation point, which milli-scale elements of the feather are oriented to reflect strongly? Do some species produce broader "windows" for observation of iridescence than others? These and similar questions may be asked about any organisms that have evolved a particular surface appearance for signaling, camouflage, or other reasons.
In order to study the directional patterns of light scattering from feathers, and their relationship to the bird's milli-scale morphology, we developed a protocol for measuring light scattered from biological materials using many high-resolution photographs taken with varying illumination and viewing directions. Since we measure scattered light as a function of direction, we can observe the characteristic features in the directional distribution of light scattered from that particular feather, and because barbs and barbules are resolved in our images, we can clearly attribute the directional features to these different milli-scale structures. Keeping the specimen intact preserves the gross-scale scattering behavior seen in nature. The method described here presents a generalized protocol for analyzing spatially- and directionally-varying light scattering from complex biological materials at multiple structural scales.

We present a non-destructive method for sampling spatial variation in the direction of light scattered from structurally complex materials. By keeping the material intact, we preserve gross-scale scattering behavior, while concurrently capturing fine-scale directional contributions with high-resolution imaging. Results are visualized in software at biologically-relevant positions and scales.

从生物材料空间定向变化的光散射测量

Light interacts with an organism's integument on a variety of spatial scales. For example in an iridescent bird: nano-scale structures produce color; the ...

科研

工程学

High-resolution, High-speed, Three-dimensional Video Imaging with Digital Fringe Projection Techniques

Digital fringe projection (DFP) techniques provide dense 3D measurements of dynamically changing surfaces.&#160;Like the human eyes and brain, DFP uses triangulation between matching points in two views of the same scene at different angles to compute depth.&#160;However, unlike a stereo-based method, DFP uses a digital video projector to replace one of the cameras1. The projector rapidly projects a known sinusoidal pattern onto the subject, and the surface of the subject distorts these patterns in the camera&#8217;s field of view. Three distorted patterns (fringe images) from the camera can be used to compute the depth using triangulation.
Unlike other 3D measurement methods, DFP techniques lead to systems that tend to be faster, lower in equipment cost, more flexible, and easier to develop.&#160;DFP systems can also achieve the same measurement resolution as the camera.&#160;For this reason, DFP and other digital structured light techniques have recently been the focus of intense research (as summarized in1-5). Taking advantage of DFP, the graphics processing unit, and optimized algorithms, we have developed a system capable of 30&#160;Hz 3D video data acquisition, reconstruction, and display for over 300,000 measurement points per frame6,7.&#160;Binary defocusing DFP methods can achieve even greater speeds8.
Diverse applications can benefit from DFP techniques. Our collaborators have used our systems for facial function analysis9, facial animation10, cardiac mechanics studies11, and fluid surface measurements, but many other potential applications exist.&#160;This video will teach the fundamentals of DFP techniques and illustrate the design and operation of a binary defocusing DFP system.

This video describes the fundamentals of digital fringe projection techniques, which provide dense 3D measurements of dynamically changing surfaces.&#160;It also demonstrates the design and operation of a high-speed binary defocusing system based on these techniques.

Digital fringe projection (DFP) techniques provide dense 3D measurements of dynamically changing surfaces.&#160;Like the human eyes and brain, DFP uses ...

High-speed Particle Image Velocimetry Near Surfaces

Multi-dimensional and transient flows play a key role in many areas of science, engineering, and health sciences but are often not well understood. The complex nature of these flows may be studied using particle image velocimetry (PIV), a laser-based imaging technique for optically accessible flows. Though many forms of PIV exist that extend the technique beyond the original planar two-component velocity measurement capabilities, the basic PIV system consists of a light source (laser), a camera, tracer particles, and analysis algorithms. The imaging and recording parameters, the light source, and the algorithms are adjusted to optimize the recording for the flow of interest and obtain valid velocity data. 
Common PIV investigations measure two-component velocities in a plane at a few frames per second. However, recent developments in instrumentation have facilitated high-frame rate (&gt; 1 kHz) measurements capable of resolving transient flows with high temporal resolution. Therefore, high-frame rate measurements have enabled investigations on the evolution of the structure and dynamics of highly transient flows. These investigations play a critical role in understanding the fundamental physics of complex flows.
A detailed description for performing high-resolution, high-speed planar PIV to study a transient flow near the surface of a flat plate is presented here. Details for adjusting the parameter constraints such as image and recording properties, the laser sheet properties, and processing algorithms to adapt PIV for any flow of interest are included.

A procedure for studying transient flows near boundaries using high-resolution, high-speed particle image velocimetry (PIV) is described here. PIV is a non-intrusive measurement technique applicable to any optically accessible flow by optimizing several parameter constraints such as the image and recording properties, the laser sheet properties, and analysis algorithms.

表面附近的高速粒子图像测速

Multi-dimensional and transient flows play a key role in many areas of science, engineering, and health sciences but are often not well understood. The ...

Measuring Material Microstructure Under Flow Using 1-2 Plane Flow-Small Angle Neutron Scattering

A new small-angle neutron scattering (SANS) sample environment optimized for studying the microstructure of complex fluids under simple shear flow is presented. The SANS shear cell consists of a concentric cylinder Couette geometry that is sealed and rotating about a horizontal axis so that the vorticity direction of the flow field is aligned with the neutron beam enabling scattering from the 1-2 plane of shear (velocity-velocity gradient, respectively). This approach is an advance over previous shear cell sample environments as there is a strong coupling between the bulk rheology and microstructural features in the 1-2 plane of shear. Flow-instabilities, such as shear banding, can also be studied by spatially resolved measurements. This is accomplished in this sample environment by using a narrow aperture for the neutron beam and scanning along the velocity gradient direction. Time resolved experiments, such as flow start-ups and large amplitude oscillatory shear flow are also possible by synchronization of the shear motion and time-resolved detection of scattered neutrons. Representative results using the methods outlined here demonstrate the useful nature of spatial resolution for measuring the microstructure of a wormlike micelle solution that exhibits shear banding, a phenomenon that can only be investigated by resolving the structure along the velocity gradient direction. Finally, potential improvements to the current design are discussed along with suggestions for supplementary experiments as motivation for future experiments on a broad range of complex fluids in a variety of shear motions.

A shear cell is developed for small-angle neutron scattering measurements in the velocity-velocity gradient plane of shear and is used to characterize complex fluids. Spatially resolved measurements in the velocity gradient direction are possible for studying shear-banding materials. Applications include investigations of colloidal dispersions, polymer solutions, and self-assembled structures.

测量材料在微流使用1-2面流小角中子散射

A new small-angle neutron scattering (SANS) sample environment optimized for studying the microstructure of complex fluids under simple shear flow is ...

Quantum State Engineering of Light with Continuous-wave Optical Parametric Oscillators

Engineering non-classical states of the electromagnetic field is a central quest for quantum optics1,2. Beyond their fundamental significance, such states are indeed the resources for implementing various protocols, ranging from enhanced metrology to quantum communication and computing. A variety of devices can be used to generate non-classical states, such as single emitters, light-matter interfaces or non-linear systems3. We focus here on the use of a continuous-wave optical parametric oscillator3,4. This system is based on a non-linear &#967;2 crystal inserted inside an optical cavity and it is now well-known as a very efficient source of non-classical light, such as single-mode or two-mode squeezed vacuum depending on the crystal phase matching. 
Squeezed vacuum is a Gaussian state as its quadrature distributions follow a Gaussian statistics. However, it has been shown that number of protocols require non-Gaussian states5. Generating directly such states is a difficult task and would require strong &#967;3 non-linearities. Another procedure, probabilistic but heralded, consists in using a measurement-induced non-linearity via a conditional preparation technique operated on Gaussian states. Here, we detail this generation protocol for two non-Gaussian states, the single-photon state and a superposition of coherent states, using two differently phase-matched parametric oscillators as primary resources. This technique enables achievement of a high fidelity with the targeted state and generation of the state in a well-controlled spatiotemporal mode.

We describe the reliable generation of non-Gaussian states of traveling optical fields, including single-photon states and coherent state superpositions, using a conditional preparation method operated on the non-classical light emitted by optical parametric oscillators. Type-I and type-II phase-matched oscillators are considered and common procedures, such as the required frequency filtering or the high-efficiency quantum state characterization by homodyning, are detailed.

光与连续波光学参量振荡器的量子态工程

Engineering non-classical states of the electromagnetic field is a central quest for quantum optics1,2. Beyond their fundamental significance, such states ...

Visualization of High Speed Liquid Jet Impaction on a Moving Surface

Two apparatuses for examining liquid jet impingement on a high-speed moving surface are described: an air cannon device (for examining surface speeds between 0 and 25 m/sec) and a spinning disk device (for examining surface speeds between 15 and 100 m/sec). The air cannon linear traverse is a pneumatic energy-powered system that is designed to accelerate a metal rail surface mounted on top of a wooden projectile. A pressurized cylinder fitted with a solenoid valve rapidly releases pressurized air into the barrel, forcing the projectile down the cannon barrel. The projectile travels beneath a spray nozzle, which impinges a liquid jet onto its metal upper surface, and the projectile then hits a stopping mechanism. A camera records the jet impingement, and a pressure transducer records the spray nozzle backpressure. The spinning disk set-up consists of a steel disk that reaches speeds of 500 to 3,000 rpm via a variable frequency drive (VFD) motor. A spray system similar to that of the air cannon generates a liquid jet that impinges onto the spinning disc, and cameras placed at several optical access points record the jet impingement. Video recordings of jet impingement processes are recorded and examined to determine whether the outcome of impingement is splash, splatter, or deposition. The apparatuses are the first that involve the high speed impingement of low-Reynolds-number liquid jets on high speed moving surfaces. In addition to its rail industry applications, the described technique may be used for technical and industrial purposes such as steelmaking and may be relevant to high-speed 3D printing.

Two experimental devices for examining liquid jet impingement on a high-speed moving surface are described: an air cannon device and a spinning disk device. The apparatuses are used to determine optimal approaches to the application of liquid friction modifier (LFM) onto rail tracks for top-of-rail friction control.

高速喷液嵌塞对移动表面的可视化

Two apparatuses for examining liquid jet impingement on a high-speed moving surface are described: an air cannon device (for examining surface speeds ...

Experimental Methods for Investigation of Shape Memory Based Elastocaloric Cooling Processes and Model Validation

Shape Memory Alloys (SMA) using elastocaloric cooling processes have the potential to be an environmentally friendly alternative to the conventional vapor compression based cooling process. Nickel-Titanium (Ni-Ti) based alloy systems, especially, show large elastocaloric effects. Furthermore, exhibit large latent heats which is a necessary material property for the development of an efficient solid-state based cooling process. A scientific test rig has been designed to investigate these processes and the elastocaloric effects in SMAs. The realized test rig enables independent control of an SMA&#39;s mechanical loading and unloading cycles, as well as conductive heat transfer between SMA cooling elements and a heat source/sink. The test rig is equipped with a comprehensive monitoring system capable of synchronized measurements of mechanical and thermal parameters. In addition to determining the process-dependent mechanical work, the system also enables measurement of thermal caloric aspects of the elastocaloric cooling effect through use of a high-performance infrared camera. This combination is of particular interest, because it allows illustrations of localization and rate effects &#8212; both important for efficient heat transfer from the medium to be cooled.
The work presented describes an experimental method to identify elastocaloric material properties in different materials and sample geometries. Furthermore, the test rig is used to investigate different cooling process variations. The introduced analysis methods enable a differentiated consideration of material, process and related boundary condition influences on the process efficiency. The comparison of the experimental data with the simulation results (of a thermomechanically coupled finite element model) allows for better understanding of the underlying physics of the elastocaloric effect. In addition, the experimental results, as well as the findings based on the simulation results, are used to improve the material properties.

Experimental methods for investigation of solid state cooling processes and characterization of elastocaloric material properties of Shape Memory Alloys (SMA) are presented. A custom-built test rig has been designed for controlling and comprehensive monitoring of elastocaloric cooling processes. Furthermore, it provides a validation platform for thermomechanically coupled modeling approaches.

基于形状记忆调查Elastocaloric冷却过程和模型验证实验方法

Shape Memory Alloys (SMA) using elastocaloric cooling processes have the potential to be an environmentally friendly alternative to the conventional vapor ...

Stimulated Stokes and Antistokes Raman Scattering in Microspherical Whispering Gallery Mode Resonators

Dielectric microspheres can confine light and sound for a length of time through high quality factor whispering gallery modes (WGM). Glass microspheres can be thought as a store of energy with a huge variety of applications: compact laser sources, highly sensitive biochemical sensors and nonlinear phenomena. A protocol for the fabrication of both the microspheres and coupling system is given. The couplers described here are tapered fibers. Efficient generation of nonlinear phenomena related to third order optical non-linear susceptibility &#935;(3) interactions in triply resonant silica microspheres is presented in this paper. The interactions here reported are: Stimulated Raman Scattering (SRS), and four wave mixing processes comprising Stimulated Anti-stokes Raman Scattering (SARS). A proof of the cavity-enhanced phenomenon is given by the lack of correlation among the pump, signal and idler: a resonant mode has to exist in order to obtain the pair of signal and idler. In the case of hyperparametric oscillations (four wave mixing and stimulated anti-stokes Raman scattering), the modes must fulfill the energy and momentum conservation and, last but not least, have a good spatial overlap.

Efficient generation of nonlinear phenomena related to third order optical non-linear susceptibility &#935;(3) interactions in triply resonant silica microspheres is presented in this paper. The interactions here reported are: Stimulated Raman Scattering (SRS), and four wave mixing processes comprising Stimulated Anti-stokes Raman Scattering (SARS).

刺激斯托克斯和反斯托克斯拉曼散射在微球形回音壁模式谐振器

Dielectric microspheres can confine light and sound for a length of time through high quality factor whispering gallery modes (WGM). Glass microspheres ...

Scanning Light Scattering Profiler (SLPS) Based Methodology to Quantitatively Evaluate Forward and Backward Light Scattering from Intraocular Lenses

The scanning light scattering profiler (SLSP) methodology has been developed for the full-angle quantitative evaluation of forward and backward light scattering from intraocular lenses (IOLs) using goniophotometer principles. This protocol describes the SLSP platform and how it employs a 360&#176; rotational photodetector sensor that is scanned around an IOL sample while recording the intensity and location of scattered light as it passes through the IOL medium. The SLSP platform can be used to predict, non-clinically, the propensity for current and novel IOL designs and materials to induce light scatter. Non-clinical evaluation of light scattering properties of IOLs can significantly reduce the number of patient complaints related to unwanted glare, glistening, optical defects, poor image quality, and other phenomena associated with the unintended light scattering. Future studies should be conducted to correlate SLSP data with clinical results to help identify which measured light scatter is most problematic for patients that have undergone cataract surgery subsequent to IOL implantation.

Scanning Light Scattering Profiler SLPS Based Methodology to Quantitatively Evaluate Forward and Backward Light Scattering from Intraocular Lenses

This protocol describes the scanning light scattering profiler (SLSP) that enables the full-angle quantitative evaluation of forward and backward scattering of light from intraocular lenses (IOLs) using goniophotometer principles.

基于扫描光散射分析器（SLPS）的方法来量化评估来自眼内镜的前向和后向光散射

The scanning light scattering profiler (SLSP) methodology has been developed for the full-angle quantitative evaluation of forward and backward light ...

Implementation of a Nonlinear Microscope Based on Stimulated Raman Scattering

Stimulated Raman scattering (SRS) microscopy uses near-infrared excitation light; therefore, it shares many multi-photon microscopic imaging properties. SRS imaging modality can be obtained using commercial laser-scanning microscopes by equipping with a non-descanned forward detector with proper bandpass filters and lock-in amplifier (LIA) detection scheme. A schematic layout of a typical SRS microscope includes the following: two pulsed laser beams, (i.e., the pump and probe directed in a scanning microscope), which must be overlapped in both space and time at the image plane, then focused by a microscope objective into the sample through two scanning mirrors (SMs), which raster the focal spot across an x-y plane. After interaction with the sample, transmitted output pulses are collected by an upper objective and measured by a forward detection system inserted in an inverted microscope. Pump pulses are removed by a stack of optical filters, whereas the probe pulses that are the result of the SRS process occurring in the focal volume of the specimen are measured by a photodiode (PD). The readout of the PD is demodulated by the LIA to extract the modulation depth. A two-dimensional (2D) image is obtained by synchronizing the forward detection unit with the microscope scanning unit. In this paper, the implementation of an SRS microscope is described and successfully demonstrated, as well as the reporting of label-free images of polystyrene beads with diameters of 3 &#181;m. It is worth noting that SRS microscopes are not commercially available, so in order to take advantage of these characteristics, the homemade construction is the only option. Since SRS microscopy is becoming popular in many fields, it is believed that this careful description of the SRS microscope implementation can be very useful for the scientific community.

In this manuscript, the implementation of a stimulated Raman scattering (SRS) microscope, obtained by the integration of an SRS experimental set-up with a laser scanning microscope, is described. The SRS microscope is based on two femtosecond (fs) laser sources, a Ti-Sapphire (Ti:Sa) and synchronized optical parametric oscillator (OPO).

基于刺激拉曼散射的非线性显微镜的实现

Stimulated Raman scattering (SRS) microscopy uses near-infrared excitation light; therefore, it shares many multi-photon microscopic imaging properties. ...