Name: fabrication of polymer microspheres for optical resonator and laser applications
Uploaded: 2017-06-02T15:00:00.000+00:00
Duration: 8 min 6 s
Description: Watch this Scientific Journal Video about Fabrication of Polymer Microspheres for Optical Resonator and Laser Applications at JoVE.com

这项工作得到JSPS / MEXT日本，朝日玻璃基金会和筑波大学前战略倡议"光与事物与生活的合奏"的KAKENHI（25708020,15K13812,15H00860，15H00986，16H02081）的部分支持。

聚合物微球的制备方案<ol><li> 蒸气扩散法 <ol><li>溶解2mg共轭聚合物，例如P1（聚[（9,9-二辛基芴-2,7-二基）] - （5-辛基噻吩并[3,4- c ]吡咯-4,6-二酮-1， （4 - [（十二烷基）羰基]苯并[1,2- b ]苯并[1,2- b ] :4,5- b &#39;]二噻吩-2,6-二基）]） 28 ，在5mL小瓶中的2mL氯仿（良溶剂）中。 </li><li>将5 mL甲醇（不良溶剂）放入50mL样品瓶中。 </li><li>将含有聚合物氯仿溶液的5mL小瓶放入含有甲醇的50mL小瓶中。 </li><li>盖上50 mL小瓶，并在25°C保持3天，以使聚合物微球沉淀。 </li></ol></li><li> 迷你乳液法 <ol><li>溶解5mg共轭聚合物，如聚y [9,9-二正辛基芴基-2,7-二基]（PFO）和聚[2-甲氧基-5-（3&#39;，7&#39;-二甲基辛氧基）-1,4-亚苯基亚乙烯基]（MDMOPPV）在1mL氯仿中。 </li><li>将30mg（〜50mM）十二烷基硫酸钠（SDS）溶于2mL去离子水中。 </li><li>加入100μL聚合物的氯仿溶液至2mL含有SDS的水中。 </li><li>用超高速匀浆器以30,000rpm剧烈搅拌氯仿/水混合物2分钟，使溶液乳化。 </li><li>保持1天，不加盖小瓶蒸发氯仿。 </li><li>将离心管在1.5毫升微量离心管中离心5分钟，以2,200×g离心。取出含SDS的上清液。 </li><li>加入2 mL去离子水，并剧烈摇匀。 </li><li>重复步骤1.2.6和1.2.7三次以清除残留的SDS。 </li></ol></li><li> 界面沉淀法 </li><li>溶解200μg聚苯乙烯（PS）和10μg的荧光染料（硼二吡啶，BODIPY）至0.2mL四氢呋喃（THF）。 </li><li>将THF溶液轻轻倒入1 mL水层。 </li><li>将两层分离的THF /水保持6小时，而不使小瓶盖住，以允许聚合物微球沉淀。 </li></ol> 2.微光致发光（μ-PL）测量<ol><li> 样品制备 <ol><li>将第1部分制备的微球的悬浮液稀释在非溶剂（ 即甲醇或去离子水）中。 </li><li>使用旋转涂布机（通常为2,000rpm，50s）将微球的稀释悬浮液旋转一滴（20-30μL）到石英基质上。 </li><li>空气干燥得到的铸膜，直到溶剂完全蒸发（约5分钟）。 </li></ol></li><li> 实验装置 <ol><li>将石英衬底（15 x 15 x 0.5 mm 3 ）放在光学微镜的样品台上oscope需要。 </li><li>找到与其他球体分离的适合μ-PL测量的明确定义的微球。 </li><li>选择激光（ 即波长，连续波或脉冲，照射时间，积分等 ）。 </li><li>选择镜头的放大倍数。 </li></ol></li><li> 测量 <ol><li>使用聚焦激光束照射微球。使用以下激光条件:cw或激发波长（ λex ）为405 nm（cw），450 nm（cw），355 nm（脉冲激光;频率，1 kHz;脉冲持续时间，7 ns）和470 nm（脉冲激光;频率，2.5MHz;脉冲持续时间，70ps）。 </li><li>使用具有300或1200个槽mm -1的光栅的光谱仪在激发点记录PL光谱。 </li><li>拍摄荧光图像。 </li><li>通过移动样品台来改变激发点。 </li><li>通过倾斜准直仪来更换检测点（如有必要）。 </li></ol></li></ol>微操作技术<ol><li> 微球的操作 <ol><li>将微球固定在石英基板上的光学显微镜的样品台上。 </li><li>找到适合于μ-PL测量的明确定义的微球。 </li><li>在微操作装置上设置塑料微针。 </li><li>使用计算机控制的操纵杆移动微针以拾取微球。 </li><li>移动微球并将其连接到另一个微球。 </li><li>从连接的微球测量μ-PL。 </li></ol></li></ol>

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	<li>Ford, W. T., Chandran, R., Turk, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Catalysts+Supported+on+Polymer+Colloids.">Catalysts Supported on Polymer Colloids.</a> Pure Appl. Chem. 60 (3), 395-400 (1988).</li><li>Chen, C. -. W., Chen, M. -. Q., Serizawa, T., Akashi, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+Situ+Synthesis+And+the+Catalytic+Properties+of+Platinum+Colloids+on+Polystyrene+Microspheres+with+Surface-Grafted+Poly(N-isopropylacrylamide).">In Situ Synthesis And the Catalytic Properties of Platinum Colloids on Polystyrene Microspheres with Surface-Grafted Poly(N-isopropylacrylamide).</a> Chem. Commun. , 831-832 (1998).</li><li>Suzuki, K., Yumura, T., Mizuguchi, M., Tanaka, Y., Chen, C. -. W., Akashi, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Poly(N-isopropylacrylamide)-Grafted+Silica+as+a+Support+of+Platinum+Colloids:+Preparation+Method,+Characterization,+and+Catalytic+Properties+in+Hydrogenation.">Poly(N-isopropylacrylamide)-Grafted Silica as a Support of Platinum Colloids: Preparation Method, Characterization, and Catalytic Properties in Hydrogenation.</a> J. Appl. Polym. Sci. 77, 2678-2684 (2000).</li><li>Zhang, S., Chen, L., Zhou, S., Zhao, D., Wu, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Facile+Synthesis+of+Hierarchically+Ordered+Porous+Carbon+via+in+Situ+Self-Assembly+of+Colloidal+Polymer+and+Silica+Spheres+and+Its+Use+as+a+Catalyst+Support.">Facile Synthesis of Hierarchically Ordered Porous Carbon via in Situ Self-Assembly of Colloidal Polymer and Silica Spheres and Its Use as a Catalyst Support.</a> Chem. Mater. 22, 3433-3440 (2010).</li><li>Kataoka, K., Harada, A., Nagasaki, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Block+Copolymer+Micelles+for+Drug+Delivery:+Design+Characterization+And+Biological+Significance.">Block Copolymer Micelles for Drug Delivery: Design Characterization And Biological Significance.</a> Adv. Drug Deliv. Rev. 47, 113-131 (2001).</li><li>Otsuka, H., Nagasaki, Y., Kataoka, 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=EGylated+Nanoparticles+for+Biological+And+Pharmaceutical+Applications.">EGylated Nanoparticles for Biological And Pharmaceutical Applications.</a> Adv. Drug Deliv. Rev. 55, 403-419 (2003).</li><li>Nishiyama, N., Kataoka, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Current+State,+Achievements,+And+Future+Prospects+of+Polymeric+Micelles+as+Nanocarriers+for+Drug+and+Gene+Delivery.">Current State, Achievements, And Future Prospects of Polymeric Micelles as Nanocarriers for Drug and Gene Delivery.</a> Pharmacol. Ther. 112, 630-648 (2006).</li><li>Velev, O. D., Kaler, E. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+Situ+Assembly+of+Colloidal+Particles+into+Miniaturized+Biosensors.">In Situ Assembly of Colloidal Particles into Miniaturized Biosensors.</a> Langmuir. 15 (11), 3693-3698 (1999).</li><li>Techawanitchai, P., Yamamoto, K., Ebara, M., Aoyagi, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Surface+Design+with+Self-Heating+Smart+Polymers+for+On-Off+Switchable+Traps.">Surface Design with Self-Heating Smart Polymers for On-Off Switchable Traps.</a> Sci. Technol. Adv. Mater. 12, 044609 (2011).</li><li>Lange, U., Roznyatovskaya, N. V., Mirsky, V. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Conducting+Polymers+in+Chemical+Sensors+And+Arrays.">Conducting Polymers in Chemical Sensors And Arrays.</a> Anal. Chim. Acta. 614, 1-26 (2008).</li><li>Rajesh, T., Kumar, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recent+Progress+in+the+Development+of+Nano-Structured+Conducting+Polymers/Nanocomposites+for+Sensor+Applications.">Recent Progress in the Development of Nano-Structured Conducting Polymers/Nanocomposites for Sensor Applications.</a> Sens. Actuators B. 136, 275-286 (2009).</li><li>Wu, C., Szymanski, C., Cain, Z., McNeill, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Conjugated+Polymer+Dots+for+Multiphoton+Fluorescence+Imaging.">Conjugated Polymer Dots for Multiphoton Fluorescence Imaging.</a> J. Am. Chem. Soc. 129, 12904-12905 (2007).</li><li>Feng, L., Zhu, C., Yuan, H., Liu, L., Lv, F., Wang, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Conjugated+Polymer+Nanoparticles:+Preparation,+Properties,+Functionalization+And+Biological+Applications.">Conjugated Polymer Nanoparticles: Preparation, Properties, Functionalization And Biological Applications.</a> Chem. Soc. Rev. 42, 6620-6634 (2013).</li><li>Pecher, J., Mecking, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nanoparticles+of+Conjugated+Polymers.">Nanoparticles of Conjugated Polymers.</a> Chem. Rev. 110, 6260-6279 (2010).</li><li>McGehee, M. D., Heeger, A. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Semiconducting+(Conjugated)+Polymers+as+Materials+for+Solid-State+Lasers.">Semiconducting (Conjugated) Polymers as Materials for Solid-State Lasers.</a> Adv. Mater. 12, 1655-1668 (2000).</li><li>Samuel, I. D. W., Turnbull, G. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Organic+Semiconductor+Lasers.">Organic Semiconductor Lasers.</a> Chem. Rev. 107, 1272-1295 (2007).</li><li>Kuehne, A. J. C., Gather, M. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Organic+Lasers:+Recent+Developments+on+Materials,+Device+Geometries,+and+Fabrication+Techniques.">Organic Lasers: Recent Developments on Materials, Device Geometries, and Fabrication Techniques.</a> Chem. Rev. 116, 12823-12864 (2016).</li><li>Furumi, S., Kanai, T., Sawada, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Widely+Tunable+Lasing+in+a+Colloidal+Crystal+Gel+Film+Permanently+Stabilized+by+an+Ionic+Liquid.">Widely Tunable Lasing in a Colloidal Crystal Gel Film Permanently Stabilized by an Ionic Liquid.</a> Adv. Mater. 23, 3815-3820 (2011).</li><li>Mikosch, A., Ciftci, S., Kuehne, A. J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Colloidal+Crystal+Lasers+from+Monodisperse+Conjugated+Polymer+Particles+via+Bottom-Up+Coassembly+in+a+Sol-Gel+Matrix.">Colloidal Crystal Lasers from Monodisperse Conjugated Polymer Particles via Bottom-Up Coassembly in a Sol-Gel Matrix.</a> ACS Nano. 10, 10195-10201 (2016).</li><li>Oraevsky, A. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Whispering-Gallery+Waves.">Whispering-Gallery Waves.</a> Quant Electron. 32 (5), 377-400 (2002).</li><li>Yamamoto, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spherical+Resonators+from+&#960;-Conjugated+Polymers.">Spherical Resonators from &#960;-Conjugated Polymers.</a> Polym. J. 48, 1045-1050 (2016).</li><li>Adachi, T., 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=Spherical+Assemblies+from+&#960;+-Conjugated+Alternating+Copolymers:+Toward+Optoelectronic+Colloidal+Crystals.">Spherical Assemblies from &#960; -Conjugated Alternating Copolymers: Toward Optoelectronic Colloidal Crystals.</a> J. Am. Chem. Soc. 135, 870-876 (2013).</li><li>Tong, L., 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=Tetramethylbithiophene+in+&#960;-Conjugated+Alternating+Copolymers+as+an+Effective+Structural+Component+for+the+Formation+of+Spherical+Assemblies.">Tetramethylbithiophene in &#960;-Conjugated Alternating Copolymers as an Effective Structural Component for the Formation of Spherical Assemblies.</a> Polym. Chem. 5, 3583-3587 (2014).</li><li>Tabata, K., 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=Self-Assembled+Conjugated+Polymer+Spheres+as+Fluorescent+Microresonators.">Self-Assembled Conjugated Polymer Spheres as Fluorescent Microresonators.</a> Sci. Rep. 4, 5902 (2014).</li><li>Kushida, S., 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=Whispering+Gallery+Resonance+from+Self-Assembled+Microspheres+of+Highly+Fluorescent+Isolated+Conjugated+Polymers.">Whispering Gallery Resonance from Self-Assembled Microspheres of Highly Fluorescent Isolated Conjugated Polymers.</a> Macromolecules. 48, 3928-3933 (2015).</li><li>Kushida, S., Braam, D., Lorke, A., Yamamoto, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Whispering+Gallery+Mode+Photoemission+From+Self-Assembled+Poly-Paraphenylenevinylene+Microspheres.">Whispering Gallery Mode Photoemission From Self-Assembled Poly-Paraphenylenevinylene Microspheres.</a> AIP Conf. Proc. ICCMSE. 1702, 090046 (2015).</li><li>Braam, D., 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=Optically+Induced+Mode+Splitting+in+Self-Assembled,+High+Quality-Factor+Conjugated+Polymer+Microcavities.">Optically Induced Mode Splitting in Self-Assembled, High Quality-Factor Conjugated Polymer Microcavities.</a> Sci. Rep. 6, 19635 (2016).</li><li>Kushida, S., 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=Conjugated+Polymer+Blend+Microspheres+for+Efficient+Long-Range+Light+Energy+Transfer.">Conjugated Polymer Blend Microspheres for Efficient Long-Range Light Energy Transfer.</a> ACS Nano. 10, 5543-5549 (2016).</li><li>Kushida, S., 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=Self-Assembled+Polycarbazole+Microspheres+as+Single-Component,+White-Colour+Resonant+Photoemitters.">Self-Assembled Polycarbazole Microspheres as Single-Component, White-Colour Resonant Photoemitters.</a> RSC Adv. 6, 52854-52857 (2016).</li><li>Aikyo, Y., 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=Enwrapping+Conjugated+Polymer+Microspheres+with+Graphene+Oxide+Nanosheets.">Enwrapping Conjugated Polymer Microspheres with Graphene Oxide Nanosheets.</a> Chem. Lett. 45, 1024-1026 (2016).</li><li>Landfester, K., 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=Semiconducting+Polymer+Nanospheres+in+Aqueous+Dispersion+Prepared+by+a+Miniemulsion+Process.">Semiconducting Polymer Nanospheres in Aqueous Dispersion Prepared by a Miniemulsion Process.</a> Adv. Mater. 14, 651-655 (2002).</li><li>Okada, D., 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=Color-Tunable+Resonant+Photoluminescence+and+Cavity-Mediated+Multistep+Energy+Transfer+Cascade.">Color-Tunable Resonant Photoluminescence and Cavity-Mediated Multistep Energy Transfer Cascade.</a> ACS Nano. 10, 7058-7063 (2016).</li><li>Pecher, J., Mecking, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nanoparticles+of+Conjugated+Polymers.">Nanoparticles of Conjugated Polymers.</a> Chem. Rev. 110, 6260-6279 (2010).</li><li>Gather, M. C., 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=Single-Cell+Biological+Lasers.">Single-Cell Biological Lasers.</a> Nat. Photon. 5, 406-410 (2011).</li><li>Schubert, M., 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=Lasing+within+Live+Cells+Containing+Intracelluler+Optical+Microresonators+for+Barcode-Type+Cell+Tagging+and+Tracking.">Lasing within Live Cells Containing Intracelluler Optical Microresonators for Barcode-Type Cell Tagging and Tracking.</a> Nano Lett. 15, 5647-5652 (2015).</li></ol>

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The selection of a good solvent and non-solvent is very important for the self-assembly of well-defined microspheres. If the solubility of a polymer is too high, precipitation will not occur. Also, in general, &#960;-conjugated polymers are hydrophobic, so polar non-solvents, such as MeOH, acetonitrile, and acetone, are often used in the vapor diffusion method to minimize the surface energy required to form a spherical shape. The interface precipitation method is often adopted for the preparation of dye-doped polymer mic...

聚合物纳米/微米粒子广泛用于各种应用，包括作为催化剂载体，柱层析填料，药物递送剂，用于细胞追踪的荧光探针，光学介质等。1,2,3,4,5 ， 6，7，8，9 。特别地，π共轭聚合物具有固有的发光和电荷导电性能，其有利于使用聚合物球10,11,12,13,14的光学，电子和光电子应用，特别是使用软组织的激光应用动物材料15,16,17 。例如，具有几百纳米直径的球体的三维集成形成胶体晶体，其在一定波长18,19处显示光子带隙。当光限制在星际周期结构中时，激光作用出现在阻带的中间。另一方面，当球体的尺寸增加到几微米尺度时，光通过聚合物/空气界面20处的全内反射被限制在单个微球内。在最大圆周处的光波的传播导致干扰，导致出现具有尖锐和周期性发射线的谐振模式。这些光学模式是所谓的"耳语画廊模式"（WGM）。术语"耳语画廊"起源于在伦敦的圣保罗大教堂，声波沿着墙壁的周围传播，让画廊另一边的人听到耳语。因为光的波长在远小于声波的亚微米尺度上，所以这样大的圆顶对于光的WGM是不必要的:微小的，微米级的，明确的容器，例如微球，微盘和微晶，满足WGM条件。 等式1是WGM谐振条件21的简单形式: nπd = lλ （1） 其中n是谐振器的折射率， d是直径， l是整数， λ是光的波长。 （1）的左边部分是通过一个圆形传播的光程长度。当光路重合时发生波长的整数倍，发生共振，而在另一波长处，光波在四舍五入时减小。 本文介绍了几种用于制备溶液中共轭聚合物的WGM共振器的微球的实验方法:蒸气扩散22,23,24,25,26,27,28,29,30，微乳液31和界面沉淀32 。每种方法都有独特的特征;例如，蒸气扩散方法提供了非常高的球形度和光滑表面的明确定义的微球体，但只有低结晶度聚合物可以形成这些微球体。另一方面，对于微乳液方法，各种共轭聚合物（包括高结晶聚合物）可以形成球体，但是表面形态不如从蒸气扩散法得到的。从染料掺杂的非共轭聚合物制备微球体，界面析出法是优选的。在所有情况下，溶剂和非溶剂的选择在球形形态的形成中起重要作用。 在本文的下半部分，介绍了μ-PL和微操作技术。对于μ-PL技术，微球分散在基底上，并且通过显微镜透镜聚焦的激光束用于照射单个分离的微球24 。通过显微镜透镜由光谱仪检测来自球体的生成的PL。移动样品台可以改变激发点的位置。检测点也可以通过倾斜exci的准直器光学元件而变化相对于检测路径28,32的光轴的激光束。为了研究球间光传播和波长转换，可以使用微操作技术32 。为了连接具有不同光学性质的几个微球体，可以使用微针拾取一个球体并将其放在另一个球体上。结合微操作技术和μ-PL方法，可以使用通过简单的自组装方法制备的共轭聚合物球进行各种光学测量。该视频文件对于希望使用软质聚合物材料用于光学应用的读者将是有用的。

<table><tbody><tr><td>polystyrene</td><td>Aldrich</td><td>132427-25G</td><td></td></tr><tr><td>sodium dodecylsulfate</td><td>Kanto Kagaku</td><td>372035-31</td><td></td></tr><tr><td>tetrahydrofuran</td><td>Wako</td><td>206-08744</td><td></td></tr><tr><td>chloroform</td><td>Wako</td><td>038-18495</td><td></td></tr><tr><td>methanol</td><td>Wako</td><td>139-13995</td><td></td></tr><tr><td>Poly(9,9-di-n-octylfluorenyl-2,7-diyl)</td><td>Aldrich</td><td>571652-500MG</td><td></td></tr><tr><td>Poly[2-methoxy-5-(3&amp;prime;,7&amp;prime;-dimethyloctyloxy)-1,4-phenylenevinylene] (MDMOPPV)</td><td>Aldrich</td><td>546461-1G</td><td></td></tr><tr><td>poly[(9,9-dioctylfluorene-2,7-diyl)-alt-(5-octylthieno[3,4-c]pyrrole-4,6-dione-1,3-diyl)] (P1)</td><td>synthesized</td><td>-</td><td>reference 28</td></tr><tr><td>poly[(N-(2-heptylundecyl)carbazole-2,7-diyl)-alt-(4,8-bis[(dodecyl)carbonyl]benzo[1,2-b:4,5-b&amp;prime;]dithiophene-2,6-diyl)] (P2)</td><td>synthesized</td><td>-</td><td>reference 28</td></tr><tr><td>fluorescent dye (boron dipyrrin; BODIPY)</td><td>synthesized</td><td>-</td><td>reference 32</td></tr><tr><td>Optical Microscope</td><td>Nicon</td><td>Eclipse LV-N</td><td></td></tr><tr><td>laser_405 nm</td><td>Hutech</td><td>DH405-10-5</td><td></td></tr><tr><td>Spectrometer</td><td>Lambda Vision</td><td>LV-MC3/T</td><td></td></tr><tr><td>Homogenizer</td><td>Microtech Nichion</td><td>Physcotron NS-360D</td><td></td></tr><tr><td>micromanipulation</td><td>Microsupport</td><td>Quick Pro QP-3RH</td><td></td></tr></tbody></table>

fabrication of polymer microspheres for optical resonator and laser applications

本文介绍了三种制备包含π共轭或非共轭聚合物的荧光微球的方法:蒸气扩散，界面沉淀和微乳液。在所有方法中，精确定义的微米尺寸的球体是从溶液中的自组装过程获得的。蒸气扩散法可以产生具有最高球形度和表面平滑度的球体，但能够形成这些球体的聚合物的类型是有限的。另一方面，在微乳液法中，微球体可以由各种类型的聚合物制成，甚至由具有共面π共轭骨架的高结晶聚合物制成。来自单一分离的微球的光致发光（PL）性质是不寻常的:PL被限制在球体内部，通过聚合物/空气界面处的全内反射在球体的圆周处传播，并且自我干扰以显示清晰和周期性的共振PL线。这些共鸣g模式是所谓的"耳语画廊模式"（WGM）。这项工作演示了如何使用微光致发光（μ-PL）技术从单个孤立球体测量WGM PL。在该技术中，聚焦的激光束照射单个微球，并通过光谱仪检测发光。然后使用显微操作技术逐个连接微球，并且在一个球体的周边激发并且从另一个微球体检测PL的情况下，证明来自耦合的微球的球间PL传播和颜色转换。这些技术，μ-PL和显微操作，可用于使用聚合物材料的微光学应用的实验。

图1显示了蒸气扩散法（a），微乳液法（b）和界面沉淀法（c）的示意图。对于蒸气扩散法（ 图1a ），将含有聚合物CHCl 3溶液（0.5mg mL -1,2mL）的5mL小瓶置于含有5mL非溶剂如MeOH的50​​mL小瓶中。盖上外部小瓶，然后在25℃下静置3天。非溶剂的蒸气缓慢扩散到溶液中，导致聚合物沉淀过饱和状态。对于微乳液法（ <strong cla...

Watch this Scientific Journal Video about Fabrication of Polymer Microspheres for Optical Resonator and Laser Applications at JoVE.com

Fabrication of Polymer Microspheres for Optical Resonator and Laser Applications

提出了从聚合物合成微球的方法，微球的操作和微光致发光测量。

用于光学谐振器和激光应用的聚合物微球的制造

This paper describes three methods of preparing fluorescent microspheres comprising &#960;-conjugated or non-conjugated polymers: vapor diffusion, ...

fabrication-polymer-microspheres-for-optical-resonator-laser

Research

JoVE Journal

Engineering

14.0K 次观看.  University of Tsukuba. 提出了从聚合物合成微球的方法，微球的操作和微光致发光测量。 

视频: Fabrication of Polymer Microspheres for Optical Resonator and Laser Applications

Fabrication of Silica Ultra High Quality Factor Microresonators

Whispering gallery resonant cavities confine light in circular orbits at their periphery.1-2 The photon storage lifetime in the cavity, quantified by the quality factor (Q) of the cavity, can be in excess of 500ns for cavities with Q factors above 100 million. As a result of their low material losses, silica microcavities have demonstrated some of the longest photon lifetimes to date1-2. Since a portion of the circulating light extends outside the resonator, these devices can also be used to probe the surroundings. This interaction has enabled numerous experiments in biology, such as single molecule biodetection and antibody-antigen kinetics, as well as discoveries in other fields, such as development of ultra-low-threshold microlasers, characterization of thin films, and cavity quantum electrodynamics studies.3-7
The two primary silica resonant cavity geometries are the microsphere and the microtoroid. Both devices rely on a carbon dioxide laser reflow step to achieve their ultra-high-Q factors (Q&gt;100 million).1-2,8-9 However, there are several notable differences between the two structures. Silica microspheres are free-standing, supported by a single optical fiber, whereas silica microtoroids can be fabricated on a silicon wafer in large arrays using a combination of lithography and etching steps. These differences influence which device is optimal for a given experiment.
Here, we present detailed fabrication protocols for both types of resonant cavities. While the fabrication of microsphere resonant cavities is fairly straightforward, the fabrication of microtoroid resonant cavities requires additional specialized equipment and facilities (cleanroom). Therefore, this additional requirement may also influence which device is selected for a given experiment.
Introduction
An optical resonator efficiently confines light at specific wavelengths, known as the resonant wavelengths of the device. 1-2 The common figure of merit for these optical resonators is the quality factor or Q. This term describes the photon lifetime (&tau;o) within the resonator, which is directly related to the resonator's optical losses. Therefore, an optical resonator with a high Q factor has low optical losses, long photon lifetimes, and very low photon decay rates (1/&tau;o). As a result of the long photon lifetimes, it is possible to build-up extremely large circulating optical field intensities in these devices. This very unique property has allowed these devices to be used as laser sources and integrated biosensors.10
A unique sub-class of resonators is the whispering gallery mode optical microcavity. In these devices, the light is confined in circular orbits at the periphery. Therefore, the field is not completely confined within the device, but evanesces into the environment. Whispering gallery mode optical cavities have demonstrated some of the highest quality factors of any optical resonant cavity to date.9,11 Therefore, these devices are used throughout science and engineering, including in fundamental physics studies and in telecommunications as well as in biodetection experiments. 3-7,12
Optical microcavities can be fabricated from a wide range of materials and in a wide variety of geometries. A few examples include silica and silicon microtoroids, silicon, silicon nitride, and silica microdisks, micropillars, and silica and polymer microrings.13-17 The range in quality factor (Q) varies as dramatically as the geometry. Although both geometry and high Q are important considerations in any field, in many applications, there is far greater leverage in boosting device performance through Q enhancement. Among the numerous options detailed previously, the silica microsphere and the silica microtoroid resonator have achieved some of the highest Q factors to date.1,9 Additionally, as a result of the extremely low optical loss of silica from the visible through the near-IR, both microspheres and microtoroids are able to maintain their Q factors over a wide range of testing wavelengths.18 Finally, because silica is inherently biocompatible, it is routinely used in biodetection experiments.
In addition to high material absorption, there are several other potential loss mechanisms, including surface roughness, radiation loss, and contamination loss.2 Through an optimization of the device size, it is possible to eliminate radiation losses, which arise from poor optical field confinement within the device. Similarly, by storing a device in an appropriately clean environment, contamination of the surface can be minimized. Therefore, in addition to material loss, surface scattering is the primary loss mechanism of concern.2,8
In silica devices, surface scattering is minimized by using a laser reflow technique, which melts the silica through surface tension induced reflow. While spherical optical resonators have been studied for many years, it is only with recent advances in fabrication technologies that researchers been able to fabricate high quality silica optical toroidal microresonators (Q&gt;100 million) on a silicon substrate, thus paving the way for integration with microfluidics.1
The present series of protocols details how to fabricate both silica microsphere and microtoroid resonant cavities. While silica microsphere resonant cavities are well-established, microtoroid resonant cavities were only recently invented.1 As many of the fundamental methods used to fabricate the microsphere are also used in the more complex microtoroid fabrication procedure, by including both in a single protocol it will enable researchers to more easily trouble-shoot their experiments.

We describe the use of a carbon dioxide laser reflow technique to fabricate silica resonant cavities, including free-standing microspheres and on-chip microtoroids. The reflow method removes surface imperfections, allowing long photon lifetimes within both devices. The resulting devices have ultra high quality factors, enabling applications ranging from telecommunications to biodetection.

硅胶超高品质因子微谐振器的制造

Whispering gallery resonant cavities confine light in circular orbits at their periphery.1-2 The photon storage lifetime in the cavity, quantified by the ...

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 ...

Development of Whispering Gallery Mode Polymeric Micro-optical Electric Field Sensors

Optical modes of dielectric micro-cavities have received significant attention in recent years for their potential in a broad range of applications. The optical modes are frequently referred to as "whispering gallery modes" (WGM) or "morphology dependent resonances" (MDR) and exhibit high optical quality factors. Some proposed applications of micro-cavity optical resonators are in spectroscopy1, micro-cavity laser technology2, optical communications3-6 as well as sensor technology. The WGM-based sensor applications include those in biology7, trace gas detection8, and impurity detection in liquids9. Mechanical sensors based on microsphere resonators have also been proposed, including those for force10,11, pressure12, acceleration13 and wall shear stress14. In the present, we demonstrate a WGM-based electric field sensor, which builds on our previous studies15,16. A candidate application of this sensor is in the detection of neuronal action potential.
The electric field sensor is based on polymeric multi-layered dielectric microspheres. The external electric field induces surface and body forces on the spheres (electrostriction effect) leading to elastic deformation. This change in the morphology of the spheres, leads to shifts in the WGM. The electric field-induced WGM shifts are interrogated by exciting the optical modes of the spheres by laser light. Light from a distributed feedback (DFB) laser (nominal wavelength of ~ 1.3 &mu;m) is side-coupled into the microspheres using a tapered section of a single mode optical fiber. The base material of the spheres is polydimethylsiloxane (PDMS). Three microsphere geometries are used: (1) PDMS sphere with a 60:1 volumetric ratio of base-to-curing agent mixture, (2) multi layer sphere with 60:1 PDMS core, in order to increase the dielectric constant of the sphere, a middle layer of 60:1 PDMS that is mixed with varying amounts (2% to 10% by volume) of barium titanate and an outer layer of 60:1 PDMS and (3) solid silica sphere coated with a thin layer of uncured PDMS base. In each type of sensor, laser light from the tapered fiber is coupled into the outermost layer that provides high optical quality factor WGM (Q ~ 106). The microspheres are poled for several hours at electric fields of ~ 1 MV/m to increase their sensitivity to electric field.

A high-sensitivity photonic micro sensor was developed for electric field detection. The sensor exploits the optical modes of a dielectric sphere. Changes in the external electric field perturb the sphere morphology leading to shifts in its optical modes. The electric field strength is measured by monitoring these optical shifts.

回音壁模式聚合物微光学电场传感器的发展

Optical modes of dielectric micro-cavities have received significant attention in recent years for their potential in a broad range of applications. The ...

Microwave Photonics Systems Based on Whispering-gallery-mode Resonators

Microwave photonics systems rely fundamentally on the interaction between microwave and optical signals. These systems are extremely promising for various areas of technology and applied science, such as aerospace and communication engineering, sensing, metrology, nonlinear photonics, and quantum optics. In this article, we present the principal techniques used in our lab to build microwave photonics systems based on ultra-high Q whispering gallery mode resonators. First detailed in this article is the protocol for resonator polishing, which is based on a grind-and-polish technique close to the ones used to polish optical components such as lenses or telescope mirrors. Then, a white light interferometric profilometer measures surface roughness, which is a key parameter to characterize the quality of the polishing. In order to launch light in the resonator, a tapered silica fiber with diameter in the micrometer range is used. To reach such small diameters, we adopt the "flame-brushing" technique, using simultaneously computer-controlled motors to pull the fiber apart, and a blowtorch to heat the fiber area to be tapered. The resonator and the tapered fiber are later approached to one another to visualize the resonance signal of the whispering gallery modes using a wavelength-scanning laser. By increasing the optical power in the resonator, nonlinear phenomena are triggered until the formation of a Kerr optical frequency comb is observed with a spectrum made of equidistant spectral lines. These Kerr comb spectra have exceptional characteristics that are suitable for several applications in science and technology. We consider the application related to ultra-stable microwave frequency synthesis and demonstrate the generation of a Kerr comb with GHz intermodal frequency.

The customized techniques developed in our lab to build microwave photonics systems based on ultra-high Q whispering gallery mode resonators are presented. The protocols to obtain and characterize these resonators are detailed, and an explanation of some of their applications in microwave photonics is given.

基于微波光子系统回音壁模式谐振器

Microwave photonics systems rely fundamentally on the interaction between microwave and optical signals. These systems are extremely promising for various ...

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

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

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

无序横向安德森本地化光聚合物光纤的制备和表征

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

Fabrication and Testing of Microfluidic Optomechanical Oscillators

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

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

制造和微流控光机振荡器测试

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

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 ...

Microfluidic Fabrication of Polymeric and Biohybrid Fibers with Predesigned Size and Shape

A &#8220;sheath&#8221; fluid passing through a microfluidic channel at low Reynolds number can be directed around another &#8220;core&#8221; stream and used to dictate the shape as well as the diameter of a core stream.&#160;Grooves in the top and bottom of a microfluidic channel were designed to direct the sheath fluid and shape the core fluid.&#160;By matching the viscosity and hydrophilicity of the sheath and core fluids, the interfacial effects are minimized and complex fluid shapes can be formed.&#160;Controlling the relative flow rates of the sheath and core fluids determines the cross-sectional area of the core fluid.&#160;Fibers have been produced with sizes ranging from 300 nm to ~1 mm, and fiber cross-sections can be round, flat, square, or complex as in the case with double anchor fibers. Polymerization of the core fluid downstream from the shaping region solidifies the fibers.&#160;Photoinitiated click chemistries are well suited for rapid polymerization of the core fluid by irradiation with ultraviolet light.&#160;Fibers with a wide variety of shapes have been produced from a list of polymers including liquid crystals, poly(methylmethacrylate), thiol-ene and thiol-yne resins, polyethylene glycol, and hydrogel derivatives. Minimal shear during the shaping process and mild polymerization conditions also makes the fabrication process well suited for encapsulation of cells and other biological components.

Two adjacent fluids passing through a grooved microfluidic channel can be directed to form a sheath around a prepolymer core; thereby&#160;determining both shape and cross-section. Photoinitiated polymerization, such as thiol click chemistry, is well suited for rapidly solidifying the core fluid into a microfiber with predetermined size and shape.

预设计尺寸和形状的聚合物纤维和生物贿赂纤维的微流体制造

A &#8220;sheath&#8221; fluid passing through a microfluidic channel at low Reynolds number can be directed around another &#8220;core&#8221; stream and ...

生物工程

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 Droplet-Based Microfluidic Approach and Microsphere-PCR Amplification for Single-Stranded DNA Amplicons

Droplet-based microfluidics enable the reliable production of homogeneous microspheres in the microfluidic channel, providing controlled size and morphology of the obtained microsphere. A microsphere copolymerized with an acrydite-DNA probe was successfully fabricated. Different methods such as asymmetric PCR, exonuclease digestion, and isolation on streptavidin-coated magnetic beads can be used to synthesize single-stranded DNA (ssDNA). However, these methods cannot efficiently use large amounts of highly purified ssDNA. Here, we describe a microsphere-PCR protocol detailing how ssDNA can be efficiently amplified and separated from dsDNA simply by pipetting from a PCR reaction tube. The amplification of ssDNA can be applied as potential reagents for the DNA microarray and DNA-SELEX (Systematic evolution of ligands by exponential enrichment) processes.

This work provides a method for the fabrication of droplet-based microfluidic platforms and the application of polyacrylamide microspheres for microsphere-PCR amplification. The microsphere-PCR method makes it possible to obtain single-stranded DNA amplicons without separating double-stranded DNA.