Name: writing bragg gratings in multicore fibers
Uploaded: 2016-04-20T14:00:00.000+00:00
Duration: 8 min 48 s
Description: Watch this Scientific Journal Video about Writing Bragg Gratings in Multicore Fibers at JoVE.com

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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	<li>Othonos, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fiber+Bragg+gratings.">Fiber Bragg gratings.</a> Rev. Sci. Instrum. 68 (12), 4309-4341 (1997).</li><li>Bland-Hawthorn, J., Englund, M., Edvell, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=New+approach+to+atmospheric+OH+suppression+using+an+aperiodic+fiber+Bragg+grating.">New approach to atmospheric OH suppression using an aperiodic fiber Bragg grating.</a> Opt. Express. 12 (24), 5902-5909 (2004).</li><li>Jovanovic, N., Guyon, O., Martinache, F., Schwab, C., Cvetojevic, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=How+to+inject+light+efficiently+into+single-mode+fibers.">How to inject light efficiently into single-mode fibers.</a> Proc. SPIE. 9147, 91477P (2014).</li><li>Bland-Hawthorn, J., 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=A+complex+multi-notch+astronomical+filter+to+suppress+the+bright+infrared+sky.">A complex multi-notch astronomical filter to suppress the bright infrared sky.</a> Nat. Comm. 2, 581 (2011).</li><li>Leon-Saval, S. G., Argyros, A., Bland-Hawthorn, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Photonic+lanterns.">Photonic lanterns.</a> Opt. Express. 18 (8), 8430-8439 (2010).</li><li>Trinh, C. Q., 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=GNOSIS:+the+first+instrument+to+use+fiber+Bragg+gratings+for+OH+suppression.">GNOSIS: the first instrument to use fiber Bragg gratings for OH suppression.</a> Astron. J. 145 (2), 51 (2013).</li><li>Content, R., 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=PRAXIS:+low+thermal+emission+high+efficiency+OH+suppressed+fiber+spectrograph.">PRAXIS: low thermal emission high efficiency OH suppressed fiber spectrograph.</a> Proc. SPIE. 9151, 91514W (2014).</li><li>Birks, T. A., Mangan, B. J., D&#236;ez, A., Cruz, J. L., Murphy, D. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Photonic+lantern'+spectral+filters+in+multi-core+fiber.">Photonic lantern' spectral filters in multi-core fiber.</a> Opt. Express. 20 (13), 13996-14008 (2012).</li><li>Askins, C., 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=Inscription+of+fiber+Bragg+gratings+in+multicore+fiber.">Inscription of fiber Bragg gratings in multicore fiber.</a> BGPP. , JWA39 (2007).</li><li>Lindley, E., 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=Core-to-core+uniformity+improvement+in+multicore+fiber+Bragg+gratings.">Core-to-core uniformity improvement in multicore fiber Bragg gratings.</a> Proc. SPIE. 9151, 91515F (2014).</li><li>Lindley, E., 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=Demonstration+of+uniform+multicore+fiber+Bragg+gratings.">Demonstration of uniform multicore fiber Bragg gratings.</a> Opt. Express. 22 (25), 31575-31581 (2014).</li><li>Tomaru, S., Yasu, M., Kawachi, M., Edahiro, T. V. A. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=VAD+single-mode+fiber+with+0.2+dB/km+loss.">VAD single-mode fiber with 0.2 dB/km loss.</a> Elec. Lett. 17 (2), 93-93 (1981).</li></ol>

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?...

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/files/ftp_upload/53326/53326fig1large.jpg" target="_blank">请点击此处查看该图的放大版本。</a>

<table><tbody><tr><td>Multicore fiber</td><td>Fujikura Ltd.</td><td></td><td>7 cores with diameter 5.5&amp;nbsp;&amp;micro;m, core separation 35&amp;nbsp;&amp;micro;m, hexagonally arranged within 125 &amp;micro;m cladding, NA = 0.177</td></tr><tr><td>Glass tapering machine</td><td>Vytran</td><td>GPX-3000</td><td></td></tr><tr><td>UV laser</td><td>Coherent</td><td>300 FreD Innova</td><td>Frequency doubled 244&amp;nbsp;nm, at least 150 mW output. CAUTION: eye damage; wear appropriate goggles</td></tr><tr><td>Phase mask</td><td>Lasiris</td><td>PM-244-1069.50-50.8</td><td>Custom component, 1069.50 nm grating period, 5.08 mm thickness</td></tr><tr><td>Capillary tubes</td><td>Polymicro</td><td>TSP200794</td><td>Inner diameter 200 &amp;micro;m, outer diameter 794 &amp;micro;m</td></tr><tr><td>Lapping machine</td><td>Logitech</td><td>PM5</td><td>Combination grinder/polisher</td></tr><tr><td>UV-curable glue</td><td>Norland</td><td>NOA-61</td><td>Cures rapidly, removable with acetone</td></tr><tr><td>Microgrit</td><td>Eminess</td><td></td><td>Al&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;: 25 &amp;micro;m and 5 &amp;micro;m particle size</td></tr><tr><td>Polishing fluid</td><td>Eminess</td><td>ULTRA-SOL 500S</td><td>SF-500S-5, ULTRA-SOL 500S N/D, 5 GAL</td></tr><tr><td>Sodium hydroxide</td><td></td><td></td><td>0.004&amp;nbsp;M</td></tr><tr><td>Fiber cleaver</td><td>Vytran</td><td>LDC-400</td><td></td></tr><tr><td>Tunable laser</td><td>JDS Uniphase</td><td>SWS15101</td><td></td></tr><tr><td>IR Camera</td><td>Xenics</td><td>XEVA-1429</td><td>320x256 pixel, 16 bit resolution</td></tr><tr><td>Oven</td><td>Thermoline Scientific</td><td>LDO-030N</td><td>For annealing at T = 110&amp;nbsp;&amp;deg;C</td></tr><tr><td>Hydrogen gas</td><td>BOC</td><td></td><td>For hydrogenating fiber. CAUTION: flammable, pressurised gas</td></tr><tr><td>Nitrogen gas</td><td>BOC</td><td></td><td>Booster for hydrogenation. CAUTION: pressurised gas</td></tr><tr><td>Acetone</td><td></td><td></td><td></td></tr><tr><td>Razor blades</td><td></td><td></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...

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 ...

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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

Implementation of a Reference Interferometer for Nanodetection

A thermally and mechanically stabilized fiber interferometer suited for examining ultra-high quality factor microcavities is fashioned. After assessing its free spectral range (FSR), the module is put in parallel with a fiber taper-microcavity system and then calibrated through isolating and eliminating random shifts in the laser frequency (i.e. laser jitter noise). To realize the taper-microcavity junction and to maximize the optical power that is transferred to the resonator, a single-mode optical fiber waveguide is pulled. Solutions containing polystyrene nanobeads are then prepared and flown to the microcavity in order to demonstrate the system&#8217;s ability to sense binding to the surface of the microcavity. Data is post-processed via adaptive curve fitting, which allows for high-resolution measurements of the quality factor as well as the plotting of time-dependent parameters, such as resonant wavelength and split frequency shifts. By carefully inspecting steps in the time-domain response and shifting in the frequency-domain response, this instrument can quantify discrete binding events.

A reference interferometer technique, which is designed to remove undesirable laser jitter noise for nanodetection, is utilized for probing an ultra-high quality factor microcavity. Instructions for assembly, setup, and data acquisition are provided, alongside the measurement process for specifying the cavity quality factor.

一个参考干涉仪的Nanodetection实施

A thermally and mechanically stabilized fiber interferometer suited for examining ultra-high quality factor microcavities is fashioned. After assessing ...

Fabrication and Testing of Microfluidic Optomechanical Oscillators

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

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

制造和微流控光机振荡器测试

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

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

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

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

1-D光子晶体空穴对纳米纤维使用飞秒激光诱导消融制造

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

A Random-displacement Measurement by Combining a Magnetic Scale and Two Fiber Bragg Gratings

Long-distance displacement measurements using optical fibers have always been a challenge in both basic research and industrial production. We developed and characterized a temperature-independent fiber Bragg grating (FBG)-based random-displacement sensor that adopts a magnetic scale as a novel transferring mechanism. By detecting shifts of two FBG center wavelengths, a full-range measurement can be obtained with a magnetic scale. For identification of the clockwise and counterclockwise rotation direction of the motor (in fact, the direction of movement of the object to be tested), there is a sinusoidal relationship between the displacement and the center wavelength shift of the FBG; as the anticlockwise rotation alternates, the center wavelength shift of the second FBG detector shows a leading phase difference of around 90&#176; (+90&#176;). As the clockwise rotation alternates, the center wavelength shift of the second FBG displays a lagging phase difference of around 90&#176; (-90&#176;). At the same time, the two FBG-based sensors are temperature independent. If there is some need for a remote monitor without any electromagnetic interference, this striking approach makes them a useful tool for determining the random displacement. This methodology is appropriate for industrial production. As the structure of the whole system is relatively simple, this displacement sensor can be used in commercial production. In addition to it being a displacement sensor, it can be used to measure other parameters, such as velocity and acceleration.

A protocol to create a full-range linear displacement sensor, combining two packaged fiber Bragg grating detectors with a magnetic scale, is presented.

通过组合磁量表和两个光纤布拉格光栅进行随机位移测量

Long-distance displacement measurements using optical fibers have always been a challenge in both basic research and industrial production. We developed ...

A Silicon-tipped Fiber-optic Sensing Platform with High Resolution and Fast Response

In this article, we introduce an innovative and practically promising fiber-optic sensing platform (FOSP) that we proposed and demonstrated recently. This FOSP relies on a silicon Fabry-Perot interferometer (FPI) attached to the fiber end, referred to as Si-FOSP in this work. The Si-FOSP generates an interferogram determined by the optical path length (OPL) of the silicon cavity. Measurand alters the OPL and thus shifts the interferogram. Due to the unique optical and thermal properties of the silicon material, this Si-FOSP exhibits an advantageous performance in terms of sensitivity and speed. Furthermore, the mature silicon fabrication industry endows the Si-FOSP with excellent reproducibility and low cost toward practical applications. Depending on the specific applications, either a low-finesse or high-finesse version will be utilized, and two different data demodulation methods will be adopted accordingly. Detailed protocols for fabricating both versions of the Si-FOSP will be provided. Three representative applications and their according results will be shown. The first one is a prototype underwater thermometer for profiling the ocean thermoclines, the second one is a flow meter to measure flow speed in the ocean, and the last one is a bolometer used for monitoring exhaust radiation from magnetically confined high-temperature plasma.

This work reports an innovative silicon-tipped fiber-optic sensing platform (Si-FOSP) for high-resolution and fast-response measurement of a variety of physical parameters, such as temperature, flow, and radiation. Applications of this Si-FOSP span from oceanographic research, mechanical industry, to fusion energy research.

一种高分辨率、快速响应的硅尖光纤传感平台

In this article, we introduce an innovative and practically promising fiber-optic sensing platform (FOSP) that we proposed and demonstrated recently. This ...

Optimized Sealing Process and Real-Time Monitoring of Glass-to-Metal Seal Structures

Residual stress is an essential factor to keeping the hermeticity and robustness of a glass-to-metal seal structure. The purpose of this report is to demonstrate a novel protocol to characterize and measure residual stress in a glass-to-metal seal structure without destroying the insulation and hermeticity of sealing materials. In this research, a femto-laser inscribed fiber Bragg grating sensor is used. The glass-to-metal seal structure that is measured consists of a metal shell, sealing glass, and Kovar conductor. To make the measurements worthwhile, the specific heat treatment of metal-to-glass seal (MTGS) structure is explored to obtain the model with best hermeticity. Then, the FBG sensor is embedded into the path of sealing glass and becomes well-fused with the glass as the temperature cools to RT. The Bragg wavelength of FBG shifts with the residual stress generated in sealing the glass. To calculate the residual stress, the relationship between Bragg wavelength shift and strain is applied, and the finite element method is also used to make the results reliable. The online monitoring experiments of residual stress in sealing glass are carried out at different loads, such as high temperature and high pressure, to broaden functions of this protocol in harsh environments.

Key procedures to optimize the sealing process and achieve real-time monitoring of the metal-to-glass seal (MTGS) structure are described in detail. The embedded fiber Bragg grating (FBG) sensor is designed to achieve online monitoring of temperature and high-level residual stress in the MTGS with simultaneous environmental pressure monitoring.

玻璃到金属密封结构的优化密封工艺和实时监控

Residual stress is an essential factor to keeping the hermeticity and robustness of a glass-to-metal seal structure. The purpose of this report is to ...

Optimizing Brillouin Optical Time-Domain Analyzers Based on Gain Spectrum Engineering

Demonstrated is a unique method for sensing performance enhancement in Brillouin optical time-domain analyzers (BOTDA). A Brillouin gain spectrum (BGS) is superimposed with two symmetric Brillouin loss spectra (BLS). This leads to a complex engineered spectrum shape that is more resistant to the sensing system noise. Instead of only one pump and probe interaction as in the conventional BOTDA setup, three optical probe waves are exploited, with one probe located in the BGS and the other two symmetrically in the BLS. Due to the resistance and insensitivity of the engineered spectrum shape to the noise, the sensing performance is enhanced by 60% and the measurand resolution is doubled.

A protocol for Brillouin optical time-domain analyzers based on gain spectrum engineering is presented. Enhancements in the sensing performance, including sensing range and measurand resolution are achieved and the excess Brillouin intensity noise is studied. The protocol introduces a new way to enhance distributed Brillouin sensing performance.

Demonstrated is a unique method for sensing performance enhancement in Brillouin optical time-domain analyzers (BOTDA). A Brillouin gain spectrum (BGS) is ...

Preparation of Extracellular Matrix Protein Fibers for Brillouin Spectroscopy

Brillouin spectroscopy is an emerging technique in the biomedical field. It probes the mechanical properties of a sample through the interaction of visible light with thermally induced acoustic waves or phonons propagating at a speed of a few km/sec. Information on the elasticity and structure of the material is obtained in a nondestructive contactless manner, hence opening the way to in vivo applications and potential diagnosis of pathology. This work describes the application of Brillouin spectroscopy to the study of biomechanics in elastin and trypsin-digested type I collagen fibers of the extracellular matrix. Fibrous proteins of the extracellular matrix are the building blocks of biological tissues and investigating their mechanical and physical behavior is key to establishing structure-function relationships in normal tissues and the changes which occur in disease. The procedures of sample preparation followed by measurement of Brillouin spectra using a reflective substrate are presented together with details of the optical system and methods of spectral data analysis.

We present a protocol for the application of Brillouin light scattering spectroscopy to elastin and trypsin-purified type I collagen fibers of the extracellular matrix to extract their full elastic properties.

细胞外基质蛋白纤维的布里渊谱的制备

Brillouin spectroscopy is an emerging technique in the biomedical field. It probes the mechanical properties of a sample through the interaction of ...

生物工程

Transmission of Multiple Signals through an Optical Fiber Using Wavefront Shaping

The transmission of multiple independent optical signals through a multimode fiber is accomplished using wavefront shaping in order to compensate for the light distortion during the propagation within the fiber. Our methodology is based on digital optical phase conjugation employing only a single spatial light modulator, where the optical wavefront is individually modulated at different regions of the modulator, one region per light signal. Digital optical phase conjugation approaches are considered to be faster than other wavefront shaping approaches, where (for example) a complete determination of the wave propagation behavior of the fiber is performed. In contrast, the presented approach is time-efficient since it only requires one calibration per light signal. The proposed method is potentially appropriate for spatial division multiplexing in communications engineering. Further application fields are endoscopic light delivery in biophotonics, especially in optogenetics, where single cells in biological tissue have to be selectively illuminated with high spatial and temporal resolution.

We demonstrate the transmission of multiple independent signals through a multimode fiber using wavefront shaping employing a single spatial light modulator. By modulating the wavefront for each signal individually, spatially separated foci are transmitted. Potential applications are multiplexed data transfer in communications engineering and endoscopic light delivery in biophotonics.

通过光纤使用波前整形多个信号的传输

The transmission of multiple independent optical signals through a multimode fiber is accomplished using wavefront shaping in order to compensate for the ...