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.

הערה: לבצע את כל השלבים תחת כיתת חדר נקי 100 תנאים טובים יותר או הבאים. הכנת 1. לדוגמא <ol style=";text-align:right;direction:rtl"><li style=";text-align:right;direction:rtl"> נקה רקיק 2 קוטר &quot;סיליקון עם נאגר תחמוצת Etch פתרון (BOE) (6 חלקים 40% 4 F NH וHF 49% חלק 1) למשך 2 דקות (זהירות: כימיקלים מסוכנים). בחר זמן לחרוט זה כדי להסיר כל חומרים אורגניים או מזהמים על פני השטח. לשטוף עם מים ללא יונים (DI) למשך כ 5 דקות. רקיק יבש עם N היבש 2. הערה: לעולם אל תעבוד לבד בעת שימוש HF. תמיד לובש משקפי מגן עם מגן פנים וציוד מגן אישי (PPE) במקרה של דליפות. הנחיות הודעה לשימוש וטיפול בפסולת HF במעבדה שבה התחריט מתבצע. הערה: שלבי 1.2-1.7 הן לנעילה אלקטרוכימיים בלבד. אם ביצוע נעילה באמצעות פירוק המשך לשלב 2. </li><li style=";text-align:right;direction:rtl"> להניח את האלקטרודה העבודה, גמגום של פלטינה (Pt) 100 ננומטר על silic הקוטר הנקי 2 &quot;על פרוסות סיליקון. </li><li style=";text-align:right;direction:rtl"> לפני תחריט הסרט דק הפלטינה, לנקות את חדר RIE של כל זיהומים או photoresist שאריות מetches היבשה הקודמת. </li><li style=";text-align:right;direction:rtl"> לשאוב את התא עד לחץ בסיס של 1 × 10 -5 Torr מושגת. ודא שהכח RF מוגדר 200 W והספיקות לחמצן והארגון מוגדרות 50 SCCM ו -10 SCCM בהתאמה. להצית את הפלזמה Ar / O 2 ולרוץ לשעה לפחות 1. </li><li style=";text-align:right;direction:rtl"> כבה את הפלזמה Ar / O 2 ולאפשר חדר פורקן לכ -10 דקות. </li><li style=";text-align:right;direction:rtl"> כדי לחרוט את פני השטח סרט דק פלטינה, לטעון את המדגם לתוך תא RIE ולשאוב את החדר עד ללחץ בסיס של 1 × 10 -5 Torr. הפעם להגדיר את קצב זרימת ארגון ל0 SCCM. להצית את הפלזמה O 2 ולתת תהליך זה לרוץ במשך 30 דקות. </li><li style=";text-align:right;direction:rtl"> כבה את הפלזמה O 2 ולתת פורקן קאמרי עבור 10 דקות. </li></ol> 2. אידוי תרמי של Photochromic מולקולת שימוש מותאם אישית Lמאייד ow טמפרטורה (LTE) <ol style=";text-align:right;direction:rtl"><li style=";text-align:right;direction:rtl"> מלא סירת ALO 2 עם 30 מ&quot;ג של BTE ולטעון למקור מנהג LTE (איור 6). </li><li style=";text-align:right;direction:rtl"> פרוסות סיליקון טען למדגם הר. </li><li style=";text-align:right;direction:rtl"> יציאות חותם תא ותא משאבה עד ללחץ בסיס של 1 x 10 -6 Torr. </li><li style=";text-align:right;direction:rtl"> להתאדות BTE בטמפרטורת setpoint של 100 ° C, עם עובי סרט של 30 ננומטר. </li><li style=";text-align:right;direction:rtl"> מייד לאחר אידוי, מבול להאיר את המדגם כדי 5 דקות של UV להפוך את חומר BTE לצורה הסגורה, 1c. </li><li style=";text-align:right;direction:rtl"> על מנת להגדיר את גודל המדגם, לדבוק פיסה קטנה של פרוסות סיליקון באמצעות סופר יהלומים לגרד קו מהקצה של משטח סיליקון. תפוס את הרקיק משני צידי קו ההתחלה ולכופף את הרקיק כלפי מטה עד שהוא פורץ במישור הגביש. </li><li style=";text-align:right;direction:rtl"> לבצע מדידות profilometer כדי לאמת BTE עובי סרט דק. כדי לעשות זאת, לשרוט את המדגם באמצעות פינצטה קצה קנס. מדוד את גובה הצעד הלוך ושובמ &#39;שריטה זה, המהווה את ההבדל בגובה בין הזכות ומיקום סמן השמאלי. הערה: אי דיוקים בעובי סרט יגרמו לאי התאמות במינון חשיפה. </li><li style=";text-align:right;direction:rtl"> מדגם שנותר בחנות בN 2 תא כפפות מלאות. </li></ol> 3. חשיפות הערה: בצע את כל החשיפות בתנאי אווירת אינרטי כדי למנוע השפלה של מדגם. <ol style=";text-align:right;direction:rtl"><li style=";text-align:right;direction:rtl"> קליב המדגם על ידי ביצוע ההליך אותו כפי שמתואר בשלב 2.6. </li><li style=";text-align:right;direction:rtl"> טען מדגם בבעל מדגם אווירת אינרטי. </li><li style=";text-align:right;direction:rtl"> הר בעל מדגם אינרטי על במה. מדגם טיהור עם N 2. </li><li style=";text-align:right;direction:rtl"> לחשוף את המדגם לזמן חשיפה הרצויה באמצעות interferometer, כמו זה שמוצג באיור 8. </li></ol> 4. אלקטרוכימי חמצון באמצעות שלוש Cell אלקטרודה הערה: בצע אלקטרוכימיה בתנאי אווירת אינרטי כדי למנוע השפלה של מדגם. <ol style=";text-align:right;direction:rtl"><li style=";text-align:right;direction:rtl"> הצמד בקבוקון זכוכית נקי על גבי הצלחת החמה. הנח בר ערבוב נקי בבקבוקון. הפעל את הבוחש. </li><li style=";text-align:right;direction:rtl"> נקה קליפ נחושת חדש עם מתנול. נקה את האלקטרודה הנגדית פלטינה עם מתנול. </li><li style=";text-align:right;direction:rtl"> שימוש בקליפ נחושת נקי, קליפ מדגם דרך אחד החורים במכסת בקבוקון הטפלון. הקפד קליפ על הפלטינה נחשפה רק. </li><li style=";text-align:right;direction:rtl"> מניחים את כובע בקבוקון הטפלון על הבקבוקון. קליפ העופרת האדומה על האלקטרודה הנגדית פלטינה ולהוביל השחורים על גבי נחושת קליפ מחזיק המדגם. </li><li style=";text-align:right;direction:rtl"> באמצעות מזרק נקי, למלא את הבקבוקון עם deionized מים המסונן (DI) דרך החור השני בכובע בקבוקון הטפלון. מלא גבוה בלי שהשקיע כל אחד מהפלטינה היחפה על המדגם. </li><li style=";text-align:right;direction:rtl"> חנקן בועה במים במשך 3-5 דקות. כבה את החנקן. </li><li style=";text-align:right;direction:rtl"> מניחים את האלקטרודה ההתייחסות לחור השני בכובע בקבוקון הטפלון. קליפ העופרת הלבנה על גבי האלקטרודה ההתייחסות. בדוק כדי לוודא שאף אחד o הפלטינה החשופהn המדגם הוא שקוע. </li><li style=";text-align:right;direction:rtl"> באמצעות voltammograph, להגדיר את מתח החמצון לרמה של 0.5 V / sec. </li><li style=";text-align:right;direction:rtl"> לאחר זמן חמצון הרצוי חלף, להפוך את הכח לvoltammograph את. </li><li style=";text-align:right;direction:rtl"> הסר את קטעים האדומים, שחורים, לבנים ומן האלקטרודה הנגדית הפלטינה, קליפ נחושת, והאלקטרודה התייחסות. </li><li style=";text-align:right;direction:rtl"> לחשוף את המדגם לUV למשך 5 דקות. </li></ol> 5. פיתוח לדוגמא - אלקטרוכימי נעילה הערה: בצע פיתוח בתנאי אווירת אינרטי כדי למנוע השפלה של מדגם. <ol style=";text-align:right;direction:rtl"><li style=";text-align:right;direction:rtl"> לפתח את המדגם ב 5 (% wt) isopropanol המסוננת, 95 אתילן גליקול (% wt) לכמות הרצויה של זמן. שים לב: 50 בדרך כלל דגימות ננומטר שפותחו עבור 30-60 שניות תוך 80 דגימות ננומטר שפותחו עבור 60-180 שניות. </li><li style=";text-align:right;direction:rtl"> מדגם יבש עם N היבש 2. </li><li style=";text-align:right;direction:rtl"> מייד לחשוף מדגם 5 דקות של UV. </li></ol> נעילת פירוק - פיתוח 6. לדוגמא </eמ &#39;&gt; הערה: בצע פיתוח בתנאי אווירת אינרטי כדי למנוע השפלה של מדגם. <ol style=";text-align:right;direction:rtl"><li style=";text-align:right;direction:rtl"> שימוש של אתילן גליקול 100 מיליליטר בכוס זכוכית נקייה, לפתח את המדגם נחשף בפעם ההתפתחות הרצויה. </li><li style=";text-align:right;direction:rtl"> מדגם יבש עם N היבש 2. מייד לחשוף מדגם 5 דקות של UV. </li></ol> 7. חשיפות מרובות <ol style=";text-align:right;direction:rtl"><li style=";text-align:right;direction:rtl"> אם ביצוע חוזר חשיפות מרובות על שלבים 3-6 עם תרגום של המדגם ביחס לאופטיקה. </li></ol>

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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...

ליתוגרפיה אופטית היא בעל חשיבות מרכזית בייצור של מבנים ננומטריים והתקנים. יש התקדמות מוגברת בטכניקות ליתוגרפיה רומן היכולת לאפשר דורות חדשים של מכשירי רומן. 8-11 במאמר זה, סקירה מוצגת בכיתה של טכניקות ליתוגרפי אופטיות כי להשיג רזולוציה תת-גל עמוק באמצעות מולקולות photoswitchable רומן. גישה זו נקראת דפוסים באמצעות אופטי-Saturable מעברים (POST). 1-3 POST הוא שיטה חדשנית nanofabrication שמשלבת באופן ייחודי את הרעיונות של להרוות מעברים אופטיים של מולקולות Photochromic, במיוחד (1,2-bis (5,5&#39;-דימתיל-2,2&#39;-bithiophen-י.ל.)) perfluorocyclopent-1-ENE. בפיהם, תרכובת זו נקראת BTE, איור 1, כגון אלו המשמשים במיקרוסקופ פליטה המאולץ-דלדול (STED) 12, עם יתוגרפיה הפרעות, שהופך אותו לכלי רב עוצמה לlargnanopatterning דואר האזור המקביל של תכונות subwavelength עמוקות על מגוון משטחים עם סיומת פוטנציאל 2 ו 3-ממדים. שכבת Photochromic היא מדינת מקור בהומוגנית אחת. כאשר שכבה זו נחשפה לתאורה אחידה של λ 1, זה הופך למדינה השנייה isomeric (ג 1), איור 2. ואז המדגם חשוף לצומת ממוקדת בλ 2, אשר ממיר את המדגם לתוך מדינת isomeric הראשונה ( 1o) בכל מקום מלבד בסביבה הקרובה לצומת. על ידי שליטה על מינון החשיפה, גודל האזור לא מומר יכול להיעשות באופן שרירותי קטן. הצעד הבא של תיקון אחד של איזומרים ניתן להמרה באופן סלקטיבי ובלתי הפיך (נעול) למצב 3 rd (בשחור) כדי לנעול את התבנית. בשלב הבא, השכבה חשופה באופן אחיד לλ 1, אשר ממיר כל דבר פרט לאזור הנעול חזרה למצב המקורי.רצף של צעדים ניתן לחזור עם תזוזה של המדגם ביחס לאופטיקה, וכתוצאה מכך שני אזורים נעולים ריווחה קטן מגבול השתברות השדה הרחוק. לכן, כל גיאומטריה שרירותית ניתן בדוגמת באופנה &quot;סיכות&quot;. 1-3

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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.

דגימות מפוברקות: פעמים חמצון שונות אופיינו כפי שמודגמים על ידי micrographs הכוח האטומי באיור 3 במתח חמצון של 0.85 V נקבע מvoltammetry המחזורית. סרטי 50 ננומטר בעובי נחשפו לגל עומד בλ = 647 nm של nm 400 תקופה של 60 שניות בצפיפות הספק של...

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.

דפוסים באמצעות מעברי Saturable אופטיים - ייצור ואפיון

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 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).

ייצור ואפיון של מנחי גלים פוטוניים Crystal להאט את האור וחללים

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.

ייצור ואפיון של סיבים אופטיים הפרעות פולימר ללוקליזציה רוחבית אנדרסון אור

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

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

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

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

הנדסה הקוונטית מדינה של אור עם גל רציף מתנדים אופטיים פרמטרים

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

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.

ייצור ובדיקה של מתנדים optomechanical Microfluidic

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.

דפוסים על תאים שקוף אופטית טין אלקטרודות תחמוצת אינדיום

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.

ייצור ותפעול של מסוע ננו-אופטי

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.

תא דפוסים על photolithographically מוגדר Parylene-C: SiO<sub&gt; 2</sub&gt; מצעים

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

Bioengineering

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.

המצאה של 1-D פוטוניים Crystal חלל על nanofiber שימוש Femtosecond אבלציה לייזר המושרה

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

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.

מדידת תנודות קצב חזרה מהירה של גבישי סוליטון במיקרו-רזנטור

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.

ססגוניות קרינת איתור עבור מיקרופלואידיקה אגל באמצעות סיבים אופטיים

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