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.

ملاحظة: تنفيذ كافة الخطوات التالية تحت الطبقة غرف الأبحاث 100 شروط أو أفضل. التحضير 1. عينة <ol style=";text-align:right;direction:rtl"><li style=";text-align:right;direction:rtl"> تنظيف رقاقة السيليكون 2 &quot;مع قطر التخزين المؤقت أكسيد حفر (البنك المركزي البريطاني) الحل (6 أجزاء 40٪ NH 4 F و 1 جزء 49٪ HF) لمدة 2 دقيقة (تنبيه: المواد الكيميائية الخطرة). اختيار هذا الوقت حفر لإزالة أي ملوثات العضوية أو على السطح. شطف مع منزوع الأيونات (DI) الماء لمدة حوالي 5 دقائق. رقاقة الجاف مع N الجاف 2. ملاحظة: أبدا العمل وحدها عند استخدام HF. ترتدي دائما حماية العين مع درع الوجه ومعدات الوقاية الشخصية (PPE) في حالة انسكاب. المبادئ التوجيهية آخر لاستخدام والتعامل مع النفايات HF في المختبر حيث يتم تنفيذ الحفر. ملاحظة: الخطوات 1،2-1،7 هي للقفل الكهروكيميائية فقط. إذا كان أداء تأمين طريق حل انتقل إلى الخطوة 2. </li><li style=";text-align:right;direction:rtl"> لوضع القطب العمل، تفل 100 نيوتن متر من البلاتين (حزب العمال) على نظيفة 2 &quot;قطر silicعلى رقاقة. </li><li style=";text-align:right;direction:rtl"> قبل الحفر الفيلم البلاتين رقيقة، وتنظيف غرفة RIE من أي شوائب أو مقاومة للضوء بقايا من يحفر الجافة السابقة. </li><li style=";text-align:right;direction:rtl"> ضخ أسفل غرفة حتى ضغط قاعدة 1 × 10 -5 ويتحقق عربة. تأكد من أن يتم تعيين سلطة RF إلى 200 W، ومن المقرر أن معدلات التدفق لالأكسجين والأرجون إلى 50 SCCM و 10 SCCM على التوالي. إشعال البلازما عار / O 2 وتشغيل لا يقل عن 1 ساعة. </li><li style=";text-align:right;direction:rtl"> إيقاف البلازما عار / O 2 والسماح للغرفة تنفيس لحوالي 10 دقيقة. </li><li style=";text-align:right;direction:rtl"> لحفر البلاتين سطح طبقة رقيقة، تحميل العينة في غرفة RIE وضخ الغرفة وصولا الى ضغط قاعدة 1 × 10 -5 عربة. هذه المرة ضبط معدل تدفق الأرجون ل0 SCCM. إشعال البلازما O 2 والسماح هذه العملية تعمل لمدة 30 دقيقة. </li><li style=";text-align:right;direction:rtl"> إيقاف البلازما O 2 والسماح للغرفة تنفيس لمدة 10 دقيقة. </li></ol> 2. التبخر الحراري للاللونية الجزيئة عن طريق مخصص Lآه المبخر درجة الحرارة (LTE) <ol style=";text-align:right;direction:rtl"><li style=";text-align:right;direction:rtl"> شغل ألو 2 قارب مع 30 ملغ من BTE وتحميل إلى مصدر LTE مخصصة (الشكل 6). </li><li style=";text-align:right;direction:rtl"> تحميل رقاقة السيليكون في عينة جبل. </li><li style=";text-align:right;direction:rtl"> الموانئ غرفة ختم وغرفة المضخة وصولا الى ضغط قاعدة 1 × 10 -6 عربة. </li><li style=";text-align:right;direction:rtl"> تتبخر BTE في درجة الحرارة المضبوطة مسبقا من 100 درجة مئوية، مع سماكة الفيلم من 30 نانومتر. </li><li style=";text-align:right;direction:rtl"> مباشرة بعد التبخر والفيضانات تسليط الضوء على عينة لمدة 5 دقائق من الأشعة فوق البنفسجية لتحويل المواد BTE إلى النموذج مغلقة، 1C. </li><li style=";text-align:right;direction:rtl"> من أجل تحديد حجم العينة، يلتصق قطعة صغيرة من الرقاقة باستخدام الكاتب الماس الى نقطة الصفر خط من على حافة سطح السيليكون. انتزاع الرقاقة على جانبي خط الصفر وثني رقاقة نزولا حتى وقوعه على طول الطائرة وضوح الشمس. </li><li style=";text-align:right;direction:rtl"> أداء قياسات profilometer للتحقق من صحة BTE سماكة رقيقة. للقيام بذلك، خدش العينة باستخدام غرامة حافة ملاقط. قياس ارتفاع خطوة جيئة وذهابام هذا الصفر، وهذا هو الفرق في الارتفاع بين الحق وموضع المؤشر الأيسر. ملاحظة: أخطاء في سماكة الفيلم يؤدي إلى اختلافات في جرعة التعرض. </li><li style=";text-align:right;direction:rtl"> متجر المتبقية العينة في N 2 شغل في صندوق قفازات. </li></ol> 3. التعرض ملاحظة: إجراء كل التعرضات في ظل ظروف الجو الخاملة لمنع تدهور العينة. <ol style=";text-align:right;direction:rtl"><li style=";text-align:right;direction:rtl"> يلتصق العينة باتباع نفس الإجراء على النحو المبين في الخطوة 2.6. </li><li style=";text-align:right;direction:rtl"> عينة الحمل في خامل صاحب العينة الغلاف الجوي. </li><li style=";text-align:right;direction:rtl"> جبل خامل صاحب العينة على خشبة المسرح. عينة تطهير مع N 2. </li><li style=";text-align:right;direction:rtl"> فضح العينة إلى وقت التعرض المطلوب باستخدام تداخل، مثل واحد هو مبين في الشكل (8). </li></ol> 4. الكهروكيميائية أكسدة عن طريق ثلاثة الكهربائي الخلية ملاحظة: إجراء الكيمياء الكهربائية في ظل ظروف الجو الخاملة لمنع تدهور العينة. <ol style=";text-align:right;direction:rtl"><li style=";text-align:right;direction:rtl"> المشبك قارورة زجاجية نظيفة على الجزء العلوي من لوحة الساخنة. وضع شريط التحريك نظيفة في القارورة. بدوره على النمام. </li><li style=";text-align:right;direction:rtl"> تنظيف مقطع النحاس جديد مع الميثانول. تنظيف الكهربائي البلاتين مواجهة مع الميثانول. </li><li style=";text-align:right;direction:rtl"> باستخدام مشبك النحاس نظيفة، مقطع العينة من خلال واحدة من الثقوب في الحد الأقصى تفلون قارورة. تأكد من مقطع على البلاتين تتعرض فقط. </li><li style=";text-align:right;direction:rtl"> وضع غطاء القارورة تفلون على القارورة. مقطع الرصاص الأحمر على القطب البلاتين المضاد والرصاص الأسود على مقطع النحاس عقد العينة. </li><li style=";text-align:right;direction:rtl"> باستخدام حقنة نظيفة، وملء قارورة مع منزوع الأيونات تصفيتها (DI) المياه من خلال ثقب الثاني في الحد الأقصى تفلون قارورة. ملء تصل إلى دون تخبط أي من البلاتين عارية على العينة. </li><li style=";text-align:right;direction:rtl"> النيتروجين فقاعة في الماء لمدة 3-5 دقيقة. إيقاف النيتروجين. </li><li style=";text-align:right;direction:rtl"> وضع القطب المرجعية في حفرة الثاني في الحد الأقصى تفلون قارورة. مقطع الرصاص الأبيض على القطب المرجعية. تحقق للتأكد أي متأكدا من البلاتين عارية سن ومغمورة العينة. </li><li style=";text-align:right;direction:rtl"> باستخدام voltammograph، تعيين الأكسدة الجهد إلى 0.5 V / ثانية. </li><li style=";text-align:right;direction:rtl"> بعد انقضاء الوقت الأكسدة المطلوب، وتحويل الطاقة إلى voltammograph قبالة. </li><li style=";text-align:right;direction:rtl"> إزالة مقاطع الأحمر والأسود، والأبيض من العداد الكهربائي البلاتين، مقطع النحاس، والقطب المرجعية. </li><li style=";text-align:right;direction:rtl"> فضح عينة للأشعة فوق البنفسجية لمدة 5 دقائق. </li></ol> 5. تطوير نموذج - الكهروكيميائية قفل ملاحظة: تنفيذ التنمية في ظل جو الخاملة لمنع تدهور العينة. <ol style=";text-align:right;direction:rtl"><li style=";text-align:right;direction:rtl"> تطوير العينة في المصفاة (5٪ بالوزن) الأيزوبروبانول، 95 (٪ بالوزن) جلايكول الإثيلين للمبلغ المطلوب من الوقت. ملاحظة: يتم تطوير عادة 50 نانومتر عينات لمدة 30-60 ثانية بينما يتم تطوير 80 نانومتر عينات ل60-180 ثانية. </li><li style=";text-align:right;direction:rtl"> عينة الجافة مع N الجاف 2. </li><li style=";text-align:right;direction:rtl"> فضح فورا عينة لمدة 5 دقائق من الأشعة فوق البنفسجية. </li></ol> 6. عينة التنمية - حل قفل </eم&gt; ملاحظة: تنفيذ التنمية في ظل جو الخاملة لمنع تدهور العينة. <ol style=";text-align:right;direction:rtl"><li style=";text-align:right;direction:rtl"> باستخدام 100 مل من جلايكول الإثيلين في كوب زجاجي نظيف وتطوير العينة المعرضة للمرة التنمية المنشودة. </li><li style=";text-align:right;direction:rtl"> عينة الجافة مع N الجاف 2. فضح فورا عينة لمدة 5 دقائق من الأشعة فوق البنفسجية. </li></ol> 7. التعرض لأخطار متعددة <ol style=";text-align:right;direction:rtl"><li style=";text-align:right;direction:rtl"> إذا كان أداء التعرض لأخطار متعددة كرر الخطوات من 3-6 مع ترجمة للعينة المتعلقة البصريات. </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...

الطباعة الحجرية الضوئية هي ذات أهمية رئيسية في تصنيع هياكل النانو والأجهزة. زيادة التقدم في تقنيات الطباعة الحجرية رواية لديه القدرة على تمكين أجيال جديدة من الأجهزة الجديدة. 8-11 في هذه المقالة، ويقدم استعراضا لفئة من تقنيات الطباعة الحجرية الضوئية التي تحقق العميق الدقة الطول الموجي الفرعية باستخدام جزيئات photoswitchable الرواية. ويسمى هذا النهج الزخرفة عبر والبصرية تشبع التحولات (POST). 1-3 المنصب هو تقنية جديدة nanofabrication يجمع بشكل فريد أفكار تشبع التحولات البصرية من الجزيئات الضوئية، وتحديدا (1،2 مكرر (5،5&#39;-ثنائي ميثيل-2،2&#39;-bithiophen-يل)) perfluorocyclopent-1-الشم. بالعامية، ويشار إلى هذا المركب كما BTE، الشكل 1، مثل تلك المستخدمة في الانبعاث المستحث استنفاد (STED) المجهري 12، مع الطباعة الحجرية تشويش مما يجعلها أداة قوية لارجمنطقة الإلكترونية nanopatterning موازية من الميزات subwavelength عميقة على مجموعة متنوعة من الأسطح مع تمديد محتمل ل2- و 3 أبعاد. طبقة الضوئية هي دولة متجانسة أصلا في واحدة. عندما يتعرض هذه الطبقة إلى الإضاءة موحدة من λ 1، فإنه يتحول لدولة ايزوميريا الثانية (1C)، الشكل 2. ثم يتعرض العينة إلى عقدة مركزة في λ 2، والذي يحول العينة إلى أول دولة ايزوميريا ( 1O) في كل مكان ما عدا في محيط القريب من العقدة. من خلال التحكم في جرعة التعرض، وحجم المنطقة غير محول يجوز صغيرة بشكل تعسفي. والخطوة اللاحقة تحديد واحد من ايزومرات يمكن بشكل انتقائي وبشكل لا رجعة فيه تحويل (مغلق) إلى دولة 3 الثالثة (باللون الأسود) لقفل النمط. وبعد ذلك، تتعرض طبقة موحد على λ 1، والذي يحول كل شيء ما عدا منطقة مغلقة يعود إلى حالته الأصلية. السلسلة من الخطوات يمكن ان تتكرر مع تشريد عينة المتعلقة البصريات، مما أدى إلى منطقتين مقفل التي تباعد أصغر من الحد حيود بعيدة الميدان. لذلك، قد يكون نمط أي هندسة التعسفية في &quot;نقطية&quot; الموضة. 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.

عينات ملفقة: تميزت مرات الأكسدة المختلفة كما يتضح من الميكروسكوب الذرية القوة في الشكل 3 في الجهد أكسدة 0.85 V تحديده من voltammetry دوري. تعرضت الأفلام 50 نانومتر سميكة لموجة دائمة في λ = 647 نيوتن متر من الفترة 400 نانومتر ?...

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.

الزخرفة عبر البصرية تشبع انتقالات - تصنيع وتوصيف

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

patterning-via-optical-saturable-transitions-fabrication

Universidad de Cartagena UDEC

Research

JoVE Journal

Engineering

6.8K Views.  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.

Video: 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).

تصنيع وتوصيف الدليل الموجي الكريستال الضوئية الخفيفة بطيئة وتجاويف

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 ...

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.

تصنيع وتوصيف المختلين بوليمر ألياف البصرية لعرضية أندرسون توطين الضوء

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

Soft Lithographic Functionalization and Patterning Oxide-free Silicon and Germanium

The development of hybrid electronic devices relies in large part on the integration of (bio)organic materials and inorganic semiconductors through a stable interface that permits efficient electron transport and protects underlying substrates from oxidative degradation. Group IV semiconductors can be effectively protected with highly-ordered self-assembled monolayers (SAMs) composed of simple alkyl chains that act as impervious barriers to both organic and aqueous solutions. Simple alkyl SAMs, however, are inert and not amenable to traditional patterning techniques. The motivation for immobilizing organic molecular systems on semiconductors is to impart new functionality to the surface that can provide optical, electronic, and mechanical function, as well as chemical and biological activity. 
Microcontact printing (&mu;CP) is a soft-lithographic technique for patterning SAMs on myriad surfaces.1-9 Despite its simplicity and versatility, the approach has been largely limited to noble metal surfaces and has not been well developed for pattern transfer to technologically important substrates such as oxide-free silicon and germanium. Furthermore, because this technique relies on the ink diffusion to transfer pattern from the elastomer to substrate, the resolution of such traditional printing is essentially limited to near 1 &mu;m.10-16
In contrast to traditional printing, inkless &mu;CP patterning relies on a specific reaction between a surface-immobilized substrate and a stamp-bound catalyst. Because the technique does not rely on diffusive SAM formation, it significantly expands the diversity of patternable surfaces. In addition, the inkless technique obviates the feature size limitations imposed by molecular diffusion, facilitating replication of very small (&lt;200 nm) features.17-23 However, up till now, inkless &mu;CP has been mainly used for patterning relatively disordered molecular systems, which do not protect underlying surfaces from degradation.
Here, we report a simple, reliable high-throughput method for patterning passivated silicon and germanium with reactive organic monolayers and demonstrate selective functionalization of the patterned substrates with both small molecules and proteins. The technique utilizes a preformed NHS-reactive bilayered system on oxide-free silicon and germanium. The NHS moiety is hydrolyzed in a pattern-specific manner with a sulfonic acid-modified acrylate stamp to produce chemically distinct patterns of NHS-activated and free carboxylic acids. A significant limitation to the resolution of many &mu;CP techniques is the use of PDMS material which lacks the mechanical rigidity necessary for high fidelity transfer. To alleviate this limitation we utilized a polyurethane acrylate polymer, a relatively rigid material that can be easily functionalized with different organic moieties. Our patterning approach completely protects both silicon and germanium from chemical oxidation, provides precise control over the shape and size of the patterned features, and gives ready access to chemically discriminated patterns that can be further functionalized with both organic and biological molecules. The approach is general and applicable to other technologically-relevant surfaces.

Here we describe a simple method for patterning oxide-free silicon and germanium with reactive organic monolayers and demonstrate functionalization of the patterned substrates with small molecules and proteins. The approach completely protects surfaces from chemical oxidation, provides precise control over feature morphology, and provides ready access to chemically discriminated patterns.

Functionalization حجرية ناعمة وخالية من الزخرفة أوكسيد السيليكون والجرمانيوم

The development of hybrid electronic devices relies in large part on the integration of (bio)organic materials and inorganic semiconductors through a ...

Bioengineering

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.

تصنيع واختبار ميكروفلويديك الميكانيكية المذبذبات

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.

الزخرفة على خلايا شفافة بصريا أقطاب إنديوم أكسيد القصدير

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

Biology

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.

تصنيع وتشغيل الحزام الناقل النانو البصرية

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.

الزخرفة الخلية على Photolithographically معرفة Parylene-C: شافي<sub&gt; 2</sub&gt; ركائز

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

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.

تصنيع 1-D الضوئية التجويف البلوري على ألياف نانوية عن طريق الاجتثاث التي يسببها الليزر الفيمتو ثانية

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

Novel Techniques for Observing Structural Dynamics of Photoresponsive Liquid Crystals

We discuss in this article the experimental measurements of the molecules in liquid crystal (LC) phase using the time-resolved infrared (IR) vibrational spectroscopy and time-resolved electron diffraction. Liquid crystal phase is an important state of matter that exists between the solid and liquid phases and it is common in natural systems as well as in organic electronics. Liquid crystals are orientationally ordered but loosely packed, and therefore, the internal conformations and alignments of the molecular components of LCs can be modified by external stimuli. Although advanced time-resolved diffraction techniques have revealed picosecond-scale molecular dynamics of single crystals and polycrystals, direct observations of packing structures and ultrafast dynamics of soft materials have been hampered by blurry diffraction patterns. Here, we report time-resolved IR vibrational spectroscopy and electron diffractometry to acquire ultrafast snapshots of a columnar LC material bearing a photoactive core moiety. Differential-detection analyses of the combination of time-resolved IR vibrational spectroscopy and electron diffraction are powerful tools for characterizing structures and photoinduced dynamics of soft materials.

Here, we present the protocols of differential-detection analyses of time-resolved infrared vibrational spectroscopy and electron diffraction which enable observations of the deformations of local structures around photoexcited molecules in a columnar liquid crystal, giving an atomic perspective on the relationship between the structure and the dynamics of this photoactive material.

تقنيات الرواية لمراقبة ديناميات الهيكلية من بلورات سائلة فوتوريسبونسيفي

We discuss in this article the experimental measurements of the molecules in liquid crystal (LC) phase using the time-resolved infrared (IR) vibrational ...

Chemistry

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.

متعدد الألوان كشف الإسفار عن القطرة على microfluidics عن طريق الألياف البصرية

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