Thanks to Michael Knutson, Paul Hamric, Greg Scott, and Chris Landes for helpful discussions and assistance related to the custom inert atmosphere sample holder and assistance in the University of Utah student machine shop. P.C. acknowledges the NSF GRFP under Grant No. 0750758. P.C. acknowledges the University of Utah Nanotechnology Training Fellowship. R.M. acknowledges a NSF CAREER Award No. 1054899 and funding from the USTAR Initiative.

注:执行下洁净室100级条件或更好以下所有步骤。 1.样品制备<ol><li>清理"直径2硅片缓冲氧化物刻蚀（BOE）解决方案（6部分40％NH 4 F和1份49％HF）2分钟（ 注意:危险化学品 ）。选择这种蚀刻时间以除去任何有机物或污染物的表面上。冲洗以去离子（DI）水中约5分钟。干燥晶片用干燥的N 2。 注意:不要使用HF时单独工作。总是戴着眼睛的保护，以防泄漏防护面罩和个人防护装备（PPE）。帖子准则在哪里进行蚀刻在实验室中使用和处理的HF浪费。 注意:步骤1.2至1.7仅用于电化学锁定 。如果执行通过溶解锁定进行第2步。 </li><li>放下工作电极，溅射铂（Pt）为100纳米到干净的2"直径的硅酸在晶圆。 </li><li>前蚀刻铂薄膜，清理从以前的干蚀刻任何杂质或剩余的光刻胶RIE室。 </li><li>抽空该室，直至1×10 -5乇达到基本压力。确保RF功率设置为200瓦，并且流速为氧气和氩气分别设置在50sccm和10sccm的。点燃的Ar / O 2等离子和运行至少1小时。 </li><li>关闭的Ar / O 2等离子体，并允许该腔室泄为大约10分钟。 </li><li>蚀刻铂薄膜表面，加载样品放入RIE室和向下泵送腔室以1×10 -5乇的基础压力。这个时间设定氩流量为0标准立方厘米。点燃O 2等离子，让这个过程运行30分钟。 </li><li>关闭的O 2等离子体，并让该室通风口10分钟。 </li></ol>光致变色分子使用自定义L 2.热蒸发流温度蒸发器（LTE）的<ol><li>填写ALO 2船BTE 30毫克，并加载到自定义的LTE源（ 图6）。 </li><li>装载硅片到样品安装。 </li><li>密封室端口和泵室下降到1×10 -6乇的基础压力。 </li><li>蒸发BTE在100℃的设定温度，以30nm的膜厚度。 </li><li>立即蒸发后，洪水照射样品以5分钟的UV改造BTE材料的封闭形式，1c上 。 </li><li>为了确定样本大小，切割的小片，使用金刚石划线划伤从硅表面的边缘的线的晶片。抢在划痕线两侧的晶片和弯曲晶片向下直至其断裂沿着晶体平面。 </li><li>执行验证BTE薄膜厚度轮廓测量。要做到这一点，从头开始用细边镊子样品。测量阶梯高度来回米此划痕，它是在左，右光标位置之间的高度差。 注:在薄膜厚度不准确将导致在曝光剂量差异。 </li><li>在N 2充满手套箱店内剩余的样品。 </li></ol> 3.曝光注:执行惰性气氛条件下，所有的风险敞口，以防止样品降解。 <ol><li>按照相同的步骤，在步骤2.6中概述裂解样品。 </li><li>在惰性气体样品架上加载样品。 </li><li>安装惰性样品架在舞台上。吹扫样品用N 2。 </li><li>利用干涉仪，将样品以期望的曝光时间暴露，如在图8中所示的那个。 </li></ol> 4.电化学氧化法三电极电池注:在惰性气氛的条件下进行电化学防止样品降解。 <ol><li>钳上热板的顶部上的干净的玻璃小瓶中。放置在小瓶一个清洁的搅拌棒。开启搅拌器。 </li><li>清洁新的铜剪辑甲醇。用甲醇清洗铂反电极。 </li><li>使用干净的铜夹，通过在特氟纶小瓶帽上的孔中的一个剪辑的样本。确保夹在只露出铂。 </li><li>把铁氟龙瓶盖到小瓶。夹在红色导线到铂电极和石墨到铜夹子拿着样品。 </li><li>使用干净的注射器，通过在特氟纶瓶盖第二孔填充用过滤的去离子（DI）水的小瓶中。作为填充不高对样品浸泡任何裸露的铂。 </li><li>通过水3-5分钟气泡的氮。关掉氮气。 </li><li>将参考电极在特氟隆瓶盖的第二个孔。剪辑铅白到参考电极。检查以确保无裸露铂邻n个样品浸入。 </li><li>用伏安，将氧化电压为0.5 V /秒。 </li><li>后所需要的氧化时间已经过去时，打开电源向伏安关闭。 </li><li>从铂反电极，铜夹，和参考电极取出红色，黑色，白色和剪辑。 </li><li>暴露样品于紫外线5分钟。 </li></ol> 5.样品开发-电化学锁定 注:在惰性气氛的条件下进行显影，以防止样品降解。 <ol><li>开发在过滤5（重量％）的异丙醇样品，95（重量％）乙二醇的时间的所需量。注意:通常为50nm的样品被开发为30-60秒，而为80nm的样品为60-180秒开发的。 </li><li>用干N 2干燥的样品。 </li><li>立即暴露样品到5分钟的紫外线。 </li></ol> 6.样品开发-溶解锁定 </eM&gt; 注:在惰性气氛的条件下进行显影，以防止样品降解。 <ol><li>在一个干净的玻璃烧杯用100毫升乙二醇中，开发所需的开发时间的暴露试料。 </li><li>用干N 2干燥的样品。立即暴露样品到5分钟的紫外线。 </li></ol> 7.多重曝光<ol><li>如果执行多次曝光重复步骤3-6具有相对于光学器件的样品的译文。 </li></ol>

<ol>
	<li>Brimhall, N., Andrew, T. L., Manthena, R. V., Menon, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Breaking+the+far-field+diffraction+limit+in+optical+nanopatterning+via+repeated+photochemical+and+electrochemical+transitions+in+photochromic+molecules.">Breaking the far-field diffraction limit in optical nanopatterning via repeated photochemical and electrochemical transitions in photochromic molecules.</a> Physical Review Letters. 107 (20), 205501 (2011).</li><li>Cantu, P., 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=Subwavelength+nanopatterning+of+photochromic+diaryethene+films.">Subwavelength nanopatterning of photochromic diaryethene films.</a> Applied Physics Letters. 100 (18), 183103 (2012).</li><li>Cantu, P., Andrew, T. L., Menon, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nanopatterning+of+diarylethene+films+via+selective+dissolution+of+one+photoisomer.">Nanopatterning of diarylethene films via selective dissolution of one photoisomer.</a> Applied Physics Letters. 103 (17), 173112 (2013).</li><li>Abbe, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Beitr&#228;ge+zur+Theorie+des+Mikroskops+und+der+mikroskopischen+Wahrnehmung.">Beitr&#228;ge zur Theorie des Mikroskops und der mikroskopischen Wahrnehmung.</a> Archiv f&#252;r mikroskopische Anatomie. 9 (1), 413-418 (1873).</li><li>Li, 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=Achieving+&#955;/20+resolution+by+one-color+initiation+and+deactivation+of+polymerization.">Achieving &#955;/20 resolution by one-color initiation and deactivation of polymerization.</a> Science. 324 (5929), 910-913 (2009).</li><li>Fischer, J., von Freymann, G., Wegener, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+materials+challenge+in+diffraction-unlimited+direct-laser-writing+optical+lithography.">The materials challenge in diffraction-unlimited direct-laser-writing optical lithography.</a> Advanced Materials. 22 (32), 3578-3582 (2010).</li><li>Mirkin, C. A., 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=Beam+pen+lithography.">Beam pen lithography.</a> Nature Nanotechnology. 5, 637-640 (2010).</li><li>Xie, X., 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=Manipulating+spatial+light+fields+for+micro-+and+nano-photonics.">Manipulating spatial light fields for micro- and nano-photonics.</a> Physica E: Low-dimensional Systems and Nanostructures. 44, 1109-1126 (2012).</li><li>Leroy, 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=High-speed+metal-insulator+transition+in+vanadium+dioxide+films+induced+by+an+electrical+pulsed+voltage+over+nano-gap+electrodes.">High-speed metal-insulator transition in vanadium dioxide films induced by an electrical pulsed voltage over nano-gap electrodes.</a> Applied Physics Letters. 100 (21), 213507 (2012).</li><li>Carr, D., Sekaric, L., Craighead, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Measurement+of+nanomechanical+resonant+structures+in+single-crystal+silicon.">Measurement of nanomechanical resonant structures in single-crystal silicon.</a> Journal of Vacuum Science &amp; Technology B. 16 (6), 3821-3824 (1998).</li><li>Wilhelmi, O., 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=Rapid+prototyping+of+nanostructured+materials+with+a+focused+ion+beam.">Rapid prototyping of nanostructured materials with a focused ion beam.</a> Japanese Journal of Applied Physics. 47 (6), 2010-5014 (2008).</li><li>Hell, S. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Far-field+optical+nanoscopy.">Far-field optical nanoscopy.</a> Science. 316 (5828), 1153-1158 (2007).</li><li>Chou, S. Y., Krauss, P. R., Renstrom, P. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nanoimprint+lithography.">Nanoimprint lithography.</a> Journal of Vacuum Science &amp; Technology B. 14, 4129 (1996).</li><li>Guillemette, M. 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=Surface+topography+induces+3D+self-orientation+of+cells+and+extracellular+matrix+resulting+in+improved+tissue+function.">Surface topography induces 3D self-orientation of cells and extracellular matrix resulting in improved tissue function.</a> Integrative Biology. 1 (2), 196-204 (2009).</li></ol>

The authors have nothing to disclose.

The fabrication, experimental setup and related operational procedures of Patterning via Optical Saturable Transitions (POST) have been described. By exploiting the linear switching properties of thermally stable photochromic molecules, POST offers new perspectives on circumventing the far-field diffraction limit.1-2,4
Previously long-term storage requirement of the samples was solved by storing the samples under N2, directly after the initial evaporation.2 How...

光学光刻是具有关键的重要性在纳米级的结构和设备的制造。在新的光刻技术的进步提高了能力，使新的一代新型设备8-11在这篇文章中，回顾，提出一类是取得使用新型的光开关分子深亚波长光学分辨率的光刻技术。这种方法被称为经光学-饱和转换（POST）图案。1-3 POST是独特地结合的饱和光致变色分子的光转换，具体地（1,2-双（5,5&#39;-二甲基-2,2&#39;- bithiophen基））的想法一新颖的纳米加工技术perfluorocyclopent -1-烯。通俗地，该化合物被称为BTE， 图1中 ，例如在受激发射损耗（STED）显微镜12使用时，与干涉光刻，这使得它的强大工具LARG深亚波长特征的e-区域并行纳米图案上的各种潜在扩展表面的至2-和3-维。 光致变色层最初是在一个均匀的状态。当该层暴露于λ1的均匀的照明，将其转换成所述第二异构态（1c）中 ， 图2，然后将样品在λ2，其中样品进入所述第一异构态（转换暴露于聚焦节点1O）无处不在，除了在节点的酒店附近。通过控制曝光剂量，未转化的区域的尺寸可以被任意小。异构体中的一个的后续定影步骤可以选择性地和不可逆变换（锁定）到第三状态（黑色）以锁定模式。接着，对层被均匀地暴露于λ1，它转换以外的所有锁定区域恢复到原来的状态。该的步骤顺序可以重复与相对于光学样品的位移，导致2锁定区域的间隔比所述远场衍射极限小。因此，任意的几何形状可被图案化在一个"点阵"时尚1-3

<table><tbody><tr><td>Isopropanol</td><td>Fisher Scientific</td><td>P/7500/15</td><td>CAUTION: flammable, use good ventilation and avoid all ignition sources.</td></tr><tr><td>Buffered Oxide Etch</td><td></td><td></td><td></td></tr><tr><td>Methanol</td><td>Ricca Chemical</td><td>48-293-2&amp;nbsp;</td><td>CAUTION: flammable, use good ventilation and avoid all ignition sources.</td></tr><tr><td>Ethylene Glycol</td><td>Sigma-Aldrich</td><td>324558</td><td>CAUTION: Harmful if swallowed</td></tr><tr><td>Silicon wafer</td><td></td><td></td><td></td></tr><tr><td>Diamond Scribe</td><td></td><td></td><td></td></tr><tr><td>Glass Beakers</td><td></td><td></td><td></td></tr><tr><td>Tweezers</td><td>Ted Pella</td><td>5226</td><td></td></tr><tr><td>Reactive Ion Etching System</td><td>Oxford</td><td>Plasma Lab 80 Plus</td><td></td></tr><tr><td>Inert Atmosphere Sample Holder</td><td>Proprietary In-house Designed</td><td></td><td></td></tr><tr><td>Polarizing beamsplitter cube</td><td>Thorlabs</td><td>PBS052</td><td></td></tr><tr><td>HeNe Laser</td><td>Melles Griot</td><td>25-LHP-171</td><td>CAUTION: Wear safety glasses</td></tr><tr><td>Half-wave plates</td><td>Thorlabs</td><td>WPH05M-633</td><td></td></tr><tr><td>Thermal Evaporator</td><td>Proprietary In-house Designed</td><td></td><td></td></tr><tr><td>TMV Super</td><td>TM Vacuum Products</td><td>TMV Super</td><td></td></tr><tr><td>Voltammograph</td><td>Bioanalytical Systems</td><td>CV-37</td><td></td></tr><tr><td>Shortwave UV lamp 365&amp;nbsp;nm</td><td>UVP Analytik Jena Company</td><td>UVGL-25</td><td>CAUTION: Wear UV safety glasses</td></tr></tbody></table>

patterning via optical saturable transitions - fabrication and characterization

This protocol describes the fabrication and characterization of nanostructures using a novel nanolithographic technique called Patterning via Optical Saturable Transitions (POST). In this technique the chemical properties of organic photochromic molecules that undergo single-photon reactions are exploited, enabling rapid top-down nanopatterning over large areas at low light intensities, thereby, allowing for the circumvention of the far-field diffraction barrier.4 Simple, cost-effective, high throughput and resolution alternatives to nanopatterning are being explored, such as, two-photon polymerization5,6, beam pen lithography (BPL)7, scanning electron beam lithography (SEBL), and focused ion beam (FIB) patterning. However, multi-photon approaches require high light intensities, which limit their potential for high throughput and offer low image contrast. Although, electron and ion beam lithographic processes offer increased resolution, the serial nature of the process is limited to slow writing speeds, which also prevents patterning of features over large areas. Beam-pen lithography is an approach towards parallel near-field optical lithography. However, the gap between the source of the beam and the surface of the photoresist needs to be controlled extremely precisely for good pattern uniformity and this is very challenging to accomplish for large arrays of beams. Patterning via Optical Saturable Transitions (POST) is an alternative optical nanopatterning technique for patterning sub-wavelength features1-3. Since this technique uses single photons instead of electrons, it is extremely fast and does not require high light intensities1-3, opening the door to massive parallelization.

制作样品: 不同的氧化时间被表征为在0.85 V的循环伏安法测定的氧化电压在图3所示的原子力显微镜照片。的50纳米厚的薄膜暴露于0.95毫瓦/ cm 2的功率密度的驻波在周期为400nmλ= 647毫微米为60秒。作为氧化时间从10分钟增加到25分钟，可以清楚地看到的对比度的损失，因为一些由1O的地区得到氧化为好。显影剂（5（重量％）的异丙醇...

Watch this Scientific Journal Video about Patterning via Optical Saturable Transitions - Fabrication and Characterization at JoVE.com

Patterning via Optical Saturable Transitions - Fabrication and Characterization

We report that the diffraction limit of conventional optical lithography can be overcome by exploiting the transitions of organic photochromic derivatives induced by their photoisomerization at low light intensities.1-3 This paper outlines our fabrication technique and two locking mechanisms, namely: dissolution of one photoisomer and electrochemical oxidation.

通过光学吸收跃迁图案 - 制备与表征

This protocol describes the fabrication and characterization of nanostructures using a novel nanolithographic technique called Patterning via Optical ...

patterning-via-optical-saturable-transitions-fabrication

Research

JoVE Journal

Engineering

6.8K 次观看.  The University of Utah. We report that the diffraction limit of conventional optical lithography can be overcome by exploiting the transitions of organic photochromic derivatives induced by their photoisomerization at low light intensities.1-3 This paper outlines our fabrication technique and two locking mechanisms, namely: dissolution of one photoisomer and electrochemical oxidation.

视频: Patterning via Optical Saturable Transitions - Fabrication and Characterization

Fabrication And Characterization Of Photonic Crystal Slow Light Waveguides And Cavities

Slow light has been one of the hot topics in the photonics community in the past decade, generating great interest both from a fundamental point of view and for its considerable potential for practical applications. Slow light photonic crystal waveguides, in particular, have played a major part and have been successfully employed for delaying optical signals1-4 and the enhancement of both linear5-7 and nonlinear devices.8-11
Photonic crystal cavities achieve similar effects to that of slow light waveguides, but over a reduced band-width. These cavities offer high Q-factor/volume ratio, for the realization of optically12 and electrically13 pumped ultra-low threshold lasers and the enhancement of nonlinear effects.14-16 Furthermore, passive filters17 and modulators18-19 have been demonstrated, exhibiting ultra-narrow line-width, high free-spectral range and record values of low energy consumption.
To attain these exciting results, a robust repeatable fabrication protocol must be developed. In this paper we take an in-depth look at our fabrication protocol which employs electron-beam lithography for the definition of photonic crystal patterns and uses wet and dry etching techniques. Our optimised fabrication recipe results in photonic crystals that do not suffer from vertical asymmetry and exhibit very good edge-wall roughness. We discuss the results of varying the etching parameters and the detrimental effects that they can have on a device, leading to a diagnostic route that can be taken to identify and eliminate similar issues.
The key to evaluating slow light waveguides is the passive characterization of transmission and group index spectra. Various methods have been reported, most notably resolving the Fabry-Perot fringes of the transmission spectrum20-21 and interferometric techniques.22-25 Here, we describe a direct, broadband measurement technique combining spectral interferometry with Fourier transform analysis.26 Our method stands out for its simplicity and power, as we can characterise a bare photonic crystal with access waveguides, without need for on-chip interference components, and the setup only consists of a Mach-Zehnder interferometer, with no need for moving parts and delay scans.
When characterising photonic crystal cavities, techniques involving internal sources21 or external waveguides directly coupled to the cavity27 impact on the performance of the cavity itself, thereby distorting the measurement. Here, we describe a novel and non-intrusive technique that makes use of a cross-polarised probe beam and is known as resonant scattering (RS), where the probe is coupled out-of plane into the cavity through an objective. The technique was first demonstrated by McCutcheon et al.28 and further developed by Galli et al.29

Use of photonic crystal slow light waveguides and cavities has been widely adopted by the photonics community in many differing applications. Therefore fabrication and characterization of these devices are of great interest. This paper outlines our fabrication technique and two optical characterization methods, namely: interferometric (waveguides) and resonant scattering (cavities).

光子晶体慢光波导和腔体的制备与表征

Slow light has been one of the hot topics in the photonics community in the past decade, generating great interest both from a fundamental point of view ...

科研

工程学

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 ...

Patterning Cells on Optically Transparent Indium Tin Oxide Electrodes

The ability to exercise precise spatial and temporal control over cell-surface interactions is an important prerequisite to the assembly of multi-cellular constructs serving as in vitro mimics of native tissues.  In this study, photolithography and wet etching techniques were used to fabricate individually addressable indium tin oxide (ITO) electrodes on glass substrates.  The glass substrates containing ITO microelectrodes were modified with poly(ethylene glycol) (PEG) silane to make them protein and cell resistive.  Presence of insulating PEG molecules on the electrode surface was verified by cyclic voltammetry employing potassium ferricyanide as a redox reporter molecule.  Importantly, the application of reductive potential caused desorption of the PEG layer, resulting in regeneration of the conductive electrode surface and appearance of typical ferricyanide redox peaks.    Application of reductive potential also corresponded to switching of ITO electrode properties from cell non-adhesive to cell-adhesive. Electrochemical stripping of PEG-silane layer from ITO microelectrodes allowed for cell adhesion to take place in a spatially defined fashion, with cellular patterns corresponding closely to electrode patterns.  Micropatterning of several cell types was demonstrated on these substrates.   In the future, the control of the biointerfacial properties afforded by this method will allow to engineer cellular microenvironments through the assembly of three or more cell types into a precise geometric configuration on an optically transparent substrate.

Non-fouling PEG silane monolayer was desorbed from individually addressable ITO electrodes on glass by application of a reductive potential. Electrochemical stripping of PEG-silane layer from ITO microelectrodes allowed for cell adhesion to take place in a spatially defined fashion, with cellular patterns corresponding closely to electrode patterns.

在光学透明的铟锡氧化物电极的图案细胞

The ability to exercise precise spatial and temporal control over cell-surface interactions is an important prerequisite to the assembly of multi-cellular ...

生物学

Fabrication and Operation of a Nano-Optical Conveyor Belt

The technique of using focused laser beams to trap and exert forces on small particles has enabled many pivotal discoveries in the nanoscale biological and physical sciences over the past few decades. The progress made in this field invites further study of even smaller systems and at a larger scale, with tools that could be distributed more easily and made more widely available. Unfortunately, the fundamental laws of diffraction limit the minimum size of the focal spot of a laser beam, which makes particles smaller than a half-wavelength in diameter hard to trap and generally prevents an operator from discriminating between particles which are closer together than one half-wavelength. This precludes the optical manipulation of many closely-spaced nanoparticles and&#160;limits the&#160;resolution of optical-mechanical systems. Furthermore, manipulation using focused beams requires beam-forming or steering optics, which can be very bulky and expensive. To address these limitations in the system scalability of conventional optical trapping our lab has devised an alternative technique which utilizes near-field optics to move particles across a chip. Instead of focusing laser beams in the far-field, the optical near field of plasmonic resonators produces the necessary local optical intensity enhancement to overcome the restrictions of diffraction and manipulate particles at higher resolution. Closely-spaced resonators produce strong optical traps which can be addressed to mediate the hand-off of particles from one to the next in a conveyor-belt-like fashion. Here, we describe how to design and produce a conveyor belt using a gold surface patterned with plasmonic C-shaped resonators and how to operate it with polarized laser light to achieve super-resolution nanoparticle manipulation and transport. The nano-optical conveyor belt chip can be produced using lithography techniques and easily packaged and distributed.

The scalability and resolution of conventional optical manipulation techniques are limited by diffraction. We circumvent the diffraction limit and describe a method of optically transporting nanoparticles across a chip using a gold surface patterned with a path of closely spaced C-shaped plasmonic resonators.

一个纳米光输送带的制作和操作

The technique of using focused laser beams to trap and exert forces on small particles has enabled many pivotal discoveries in the nanoscale biological ...

Cell Patterning on Photolithographically Defined 
Parylene-C: SiO2 Substrates

Cell patterning platforms support broad research goals, such as construction of predefined in vitro neuronal networks and the exploration of certain central aspects of cellular physiology. To easily combine cell patterning with Multi-Electrode Arrays (MEAs) and silicon-based &#8216;lab on a chip&#8217; technologies, a microfabrication-compatible protocol is required. We describe a method that utilizes deposition of the polymer parylene-C on SiO2&#160;wafers. Photolithography enables accurate and reliable patterning of parylene-C at micron-level resolution. Subsequent activation by immersion in fetal bovine serum (or another specific activation solution) results in a substrate in which cultured cells adhere to, or are repulsed by, parylene or SiO2 regions respectively. This technique has allowed patterning of a broad range of cell types (including primary murine hippocampal cells, HEK 293 cell line, human neuron-like teratocarcinoma cell line, primary murine cerebellar granule cells, and primary human glioma-derived stem-like cells). Interestingly, however, the platform is not universal; reflecting the importance of cell-specific adhesion molecules. This cell patterning process is cost effective, reliable, and importantly can be incorporated into standard microfabrication (chip manufacturing) protocols, paving the way for integration of microelectronic technology.

Cell Patterning on Photolithographically Defined 
Parylene-C: SiO2 Substrates

This protocol describes a microfabrication-compatible method for cell patterning on SiO2. A predefined parylene-C design is photolithographically printed on SiO2 wafers. Following incubation with serum (or other activation solution) cells adhere specifically to (and grow according to the conformity of) underlying parylene-C, whilst being repulsed by SiO2 regions.

在光刻技术定义的聚对二甲苯-C细胞图案：二氧化硅<sub&gt; 2</sub&gt;基板

Cell patterning platforms support broad research goals, such as construction of predefined in vitro neuronal networks and the exploration of certain ...

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 ...

Characterization of SiN Integrated Optical Phased Arrays on a Wafer-Scale Test Station

Optical phased arrays (OPAs) can produce low-divergence laser beams and can be used to control the emission angle electronically without the need for moving mechanical parts. This technology is particularly useful for beam steering applications. Here, we focus on OPAs integrated into SiN photonic circuits for a wavelength in the near infrared. A characterization method of such circuits is presented, which allows the output beam of integrated OPAs to be shaped and steered. Furthermore, using a wafer-scale characterization setup, several devices can easily be tested across multiple dies on a wafer. In this way, fabrication variations can be studied, and high-performance devices identified. Typical images of OPA beams are shown, including beams emitted from OPAs with and without a uniform waveguide length, and with varying numbers of channels. In addition, the evolution of output beams during the phase optimization process and beam steering in two dimensions is presented. Finally, a study of the variation in the beam divergence of identical devices is performed with respect to their position on the wafer.

Here, we describe the operation of a SiN integrated photonic circuit containing optical phased arrays. The circuits are used to emit low divergence laser beams in the near infrared and steer them in two dimensions.

晶圆级试验站上SiN集成光学相控阵列的特性

Optical phased arrays (OPAs) can produce low-divergence laser beams and can be used to control the emission angle electronically without the need for ...

Rapid Repetition Rate Fluctuation Measurement of Soliton Crystals in a Microresonator

Temporal solitons have attracted great interest in the past decades for their behavior in a steady state, where the dispersion is balanced by the nonlinearity in a propagation Kerr medium. The development of dissipative Kerr solitons (DKSs) in high-Q microcavities drives a novel, compact, chip-scale soliton source. When DKSs serve as femtosecond pulses, the repetition rate fluctuation can be applied to ultrahigh precision metrology, high-speed optical sampling, and optical clocks, etc. In this paper, the rapid repetition rate fluctuation of soliton crystals (SCs), a special state of DKSs where particle-like solitons are tightly packed and fully occupy a resonator, is measured based on the well-known delayed self-heterodyne method. The SCs are generated using a thermal-controlled method. The pump is a frequency fixed laser with a linewidth of 100 Hz. The integral time in frequency fluctuation measurements is controlled by the length of the delay fiber. For a SC with a single vacancy, the repetition rate fluctuations are ~53.24 Hz within 10 &#181;s and ~509.32 Hz within 125 &#181;s, respectively.

Here, we present a protocol to generate soliton crystals in a butterfly-packaged micro-ring resonator using a thermal tuned method. Further, the repetition rate fluctuations of a soliton crystal with a single vacancy are measured using a delayed self-heterodyne method.

微谐振器中孤子晶体的快速重复率波动测量

Temporal solitons have attracted great interest in the past decades for their behavior in a steady state, where the dispersion is balanced by the ...

Multicolor Fluorescence Detection for Droplet Microfluidics Using Optical Fibers

Fluorescence assays are the most common readouts used in droplet microfluidics due to their bright signals and fast time response. Applications such as multiplex assays, enzyme evolution, and molecular biology enhanced cell sorting require the detection of two or more colors of fluorescence. Standard multicolor detection systems that couple free space lasers to epifluorescence microscopes are bulky, expensive, and difficult to maintain. In this paper, we describe a scheme to perform multicolor detection by exciting discrete regions of a microfluidic channel with lasers coupled to optical fibers. Emitted light is collected by an optical fiber coupled to a single photodetector. Because the excitation occurs at different spatial locations, the identity of emitted light can be encoded as a temporal shift, eliminating the need for more complicated light filtering schemes. The system has been used to detect droplet populations containing four unique combinations of dyes and to detect sub-nanomolar concentrations of fluorescein.

Multicolor fluorescence detection in droplet microfluidics typically involves bulky and complex epifluorescence microscope-based detection systems. Here we describe a compact and modular multicolor detection scheme that utilizes an array of optical fibers to temporally encode multicolor data collected by a single photodetector.

使用多色荧光检测液滴微流控光纤

Fluorescence assays are the most common readouts used in droplet microfluidics due to their bright signals and fast time response. Applications such as ...