This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 within the LDRD program.

1. Vorbereitung der Polierer und Gülle Bereiten Sie zuerst die Convergent Poliersystem (genauer gesagt mit dem Namen C onvergent, ich nitial Oberflächen Independent, S ingle Iteration, R ogue partikelfreie Polierer oder CISR (ausgesprochen &#39;Schere&#39;)) 7,17 durch die Installation des Pad &amp; Septum, Anlage das Pad, Verdünnen und chemischen Stabilisierung der Aufschlämmung und Einbeziehung der Aufschlämmung innerhalb des Filtrationssystems. <ol><li> Auf der CISR Polierer, sich ein Polyurethan-Pad auf den Granit Runde Basis. Halten Sie Pad eine Kante zuerst und Druck in Richtung auf die gegenüberliegende Kante Luftspalte zu minimieren. Schneiden Sie die überstehenden Unterlage und verwenden Sie dann eine Rasierklinge und Rollendurchstoßen und Luftblasen entfernen, wenn nötig. </li><li> Bei der ersten Inbetriebnahme und nach jeder ~ 100 hr von Polieren, Diamant Zustand des Pads unter Verwendung eines CMP Diamantkonditionierer (50 mm Durchmesser, 0,6 psi aufgebrachte Druck, 5 min Verweilzeit an jeder radialen Runde Lage mit Abstand 25 mm-Schritten; Runde Dreh 25 rpm) mit fließenden DI-Wasser. </li><li> Zwischen Polieren Iterationen, entfernen Sie alle Restschlamm und Glaswaren aus dem Pad mit einem in-situ-Ultraschall-Reiniger (~ 2 min Verweilzeit an jeder radialen Position; Runde Dreh 5 rpm) mit fließenden DI-Wasser. </li><li> Auf der einzigartig geformten Septum Gewicht, sich Doppelklebeband und dann das Septum Material (zB Pre-Cut Glas oder anderen verschleißfreie Material). Schneiden Sie überhängende Schaumstoffband, um die Form der Nasenscheidewand Material und Gewicht entsprechen. Notieren Sie sich die Scheidewand-Design (beide Form und Gewicht) ändert für verschiedene Größen des Werkstücks und Runden 7,17. </li><li> Bereiten Polieraufschlämmung Baume 4 Konzentration (genauer Mischungsvolumen ~ 1 Teil Ceroxid Polieraufschlämmung und ~ 9 Teile entionisiertes (DI) Wasser in einem 11 L bucket). Überprüfen Baume mit einem Baume Schwimmer. Hinzufügen ~ 5 ml KOH (10 M) auf pH-Wert auf 9,5 einzustellen, und fügen ~ 120 ml (1 Vol%) des proprietären Tensid 19. Nachstellen pH und Baume alle 24 Stunden des Polierens. </li><li> Installieren Eimer mit der hergestellten Aufschlämmung in Filtersystem. Dann die gewünschten CMP Partikelfilter zu installieren in Filtersystem. Lassen Aufschlämmung Rezirkulat im Filtrationssystem für mehrere Stunden. </li><li> Messen Sie Partikelgrößenverteilung von Gülle (zB mit Einzelpartikel optische Messtechniken), um das hintere Ende der Verteilung zu gewährleisten ist ausreichend Schurkenpartikelfrei 9,20. </li></ol> 2. Herstellung von Werkstück (Radierung und Blocking) Vor dem Polieren chemisch zu ätzen, die, wie er erhalten feingeschliffenen Werkstück, um die Menge der Materialentfernung benötigt, um den Untergrund Schleifen Schäden 21 entfernen zu reduzieren. Dann blockieren die Werkstück (wenn das Seitenverhältnis (dh Länge / Dicke)&gt; 10) unter Verwendung eines neuen Pitch-Taste Sperr (PBB) Technik, um das Werkstück während der Sperrung und Polieren 22 Biegen zu verhindern. <ol><li> Ätzen der feingeschliffenen Werkstücks (insbesondere eine 265 x 265 x 8 mm 3 Quarzglas flach) in einem Behälter mit HF gefüllt: NH 4 F (6: 1 gepufferten Oxidätzung (BOE) 3x verdünnt mit DI-Wasser) für 6 Stunden entfernt 10 &amp; mgr; m von Glas von der Oberfläche des Werkstücks. VORSICHT! BOE ist extrem gefährlich; Tragen Sie geeignete Schutzausrüstung (PSA). Entfernen Sie Werkstück von Ätztank und das Werkstück mit VE-Wasser spülen aggressiv und lassen Sie das Werkstück in die Luft vertikal trocknen. </li><li> Untersuchen Sie das Werkstück für tiefe Beschädigungen während des Schleifvorgangs mit einem hellen Licht Inspektion in einem dunklen Raum. Wenn keine tiefen Schäden festgestellt werden, mit dem nächsten Schritt fortfahren, sonst schicken Werkstück zurück zum Nachschleifen. </li><li> Heizen Sie blockieren Abstand in einer Klebepistole, um ~ 95 ° C und Ort Tröpfchen (auch als Tasten) der Tonhöhe (~ 0,06 g) auf das Gesicht derPrägeplatte in einem 9 x 9-Array (81 Tasten mit 26 mm Abstand). Für unterschiedlich große Werkstücke, siehe Regeln für die ideale Anzahl, Größe und Abstände der Pitch-Taste 22 zu entwerfen. Legen Sie die blockierende Platte mit dem aufgebrachten Tasten Seite nach oben in den vorgeheizten Ofen bei 70 ºC. </li><li> Das Band auf der Seite des Werkstücks, die nicht poliert werden sollen. Vermeiden Sie die Erzeugung von Luftblasen oder übermäßig das Band dehnen. </li><li> Legen Sie das Werkstück mit der Bandseite nach unten, auf Tasten auf der Sperrplatte in den Ofen. Decken Sie die Werkstück-Tasten-Block, um konvektive Strömung zu minimieren. Nach 1,5 Stunden, eingestellt Ofen auf Raumtemperatur abkühlen 10 ºC / h. Nach dem Erkalten sollen die Tonhöhenstärke am Werkstück blockiert ~ 1 mm. </li></ol> 3. Konvergente Polieren <ol><li> Schalten Sie Feuchtigkeitssystem der Umweltkammer CISR Polierschlamm auf dem Austrocknen beim Polieren zu verhindern und die Rogue-Partikel Kratzen Sie das Werkstück zu minimieren. </li><li> Insgroß und montieren Sie die speziell entwickelt und vorbereitet Septum in Polierer. Installieren PBB Werkstück in CISR Polierer und Untergurt, das Werkstück zu halten. </li><li> Polish Werkstück auf CISR 4 h bei einer angepaßten Schoß und Werkstückdrehgeschwindigkeit von 25 Umdrehungen pro Minute mit einem radialen Hub von ~ 75 mm und mit einer Aufschlämmung von Strömungsfiltrationssystem von 1 gal / min. HINWEIS: Die Sperrplatte dient auch als das Belastungsgewicht an dem Werkstück entspricht, 0,6 psi Druck aufgebracht. </li><li> Schalten Schoß und Werkstückdrehung und Schlammstrom. Entfernen PBB Werkstück von CISR Polierer und tauchen sie in DI-Wasser gefüllt Badewanne. Wischen Werkstückoberfläche mit Reinraum-Tuch, während unter Wasser. Entfernen PBB Werkstück von Bad und sprühen gründlich mit VE-Wasser. </li><li> Deblock Werkstück, indem Sie einen Shim am Werkstück-Block-Schnittstelle. Entfernen Sie das Klebeband von der Werkstückoberfläche. Aggressiv spülen Werkstück mit VE-Wasser und der Luft trocknen. </li><li> PBB die gegenüberliegende Fläche des Werkstücks, wie in Abschnitt 2 beschrieben Wiederholen poGründung Vorgehensweise wie in Kapitel 3 beschrieben. </li></ol> 4. Messtechnik und Inspektion <ol><li> Messen reflektierten Wellenfront (dh Oberflächen Abbildung) auf beiden Seiten des Werkstücks sowie Wellenfront- Verwendung eines Interferometers. </li><li> Berg Werkstück auf helles Licht Prüfstation und messen die Kratzer / dig Eigenschaften mit Hilfe der optischen Fertigung von Standardmethoden. Ein kurzer BOE Ätzung des Werkstücks, wie in Schritt 2.1 beschrieben, kann verwendet werden, um versteckte Kratzer für Werkstücke in hohen Einfluss Laseranwendungen freizulegen. Zur Messung von feinen Kratzern oder Rauheit auf dem Werkstück können Standardlichtmikroskopie oder Weißlicht-Interferometrie verwendet werden. </li><li> Speicher abgeschlossen Werkstückes in einem Behälter Minimierung des Kontakts mit dem Gesicht des Werkstücks. </li></ol>

<ol>
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Soc. 93 (5), 1326-1340 (2010).</li><li>Suratwala, T., Steele, R., Feit, M., Desjardin, R., Mason, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Convergent+Pad+Polishing+of+amorphous+fused+silica.">Convergent Pad Polishing of amorphous fused silica.</a> International Journal of Applied Glass Science. 3 (1), 14-28 (2012).</li><li>Suratwala, T., Feit, M., Steele, R., Wong, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Influence+of+Temperature+and+Material+Deposit+on+Material+Removal+Uniformity+during+Optical+Pad+Polishing.">Influence of Temperature and Material Deposit on Material Removal Uniformity during Optical Pad Polishing.</a> J. Am. Ceram. Soc. , (2014).</li><li>Suratwala, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microscopic+removal+function+and+the+relationship+between+slurry+particle+size+distribution+and+workpiece+roughness+during+pad+polishing.">Microscopic removal function and the relationship between slurry particle size distribution and workpiece roughness during pad polishing.</a> J. Am. Ceram. Soc. 91 (1), 81-91 (2014).</li><li>Terrell, E., Higgs, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hydrodynamics+of+Slurry+Flow+in+Chemical+Mechanical+Polishing.">Hydrodynamics of Slurry Flow in Chemical Mechanical Polishing.</a> J. Electrochem. Soc. 153 (6), 15-22 (2006).</li><li>Runnels, S., Eyman, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tribology+Analysis+of+Chemical+MechanicalPolishing.">Tribology Analysis of Chemical MechanicalPolishing.</a> J. Electrochem. Soc. 141 (6), 1698-1701 (1994).</li><li>Park, S., Cho, C., Ahn, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hydrodynamic+Analysis+of+Chemical+Mechanical+Polishing+Process.">Hydrodynamic Analysis of Chemical Mechanical Polishing Process.</a> J. 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Solid State. 12 (6), 191-194 (2009).</li><li>Suratwala, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Method+and+system+for+Convergent+Polishing.">Method and system for Convergent Polishing.</a> US Provisional Patent Application. , (2011).</li><li>Suratwala, T., Feit, M., Steele, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Apparatus+and+Method+for+Deterministic+Control+of+Surface+Figure+During+Full+Aperture+Polishing.">Apparatus and Method for Deterministic Control of Surface Figure During Full Aperture Polishing.</a> US Patent Application. US. , (2010).</li><li>Dylla-Spears, R., Feit, M., Miller, P., Steele, R., Suratwala, T., Wong, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Method+for+preventing+agglomeration+of+charged+colloids+without+loss+of+surface+activity.">Method for preventing agglomeration of charged colloids without loss of surface activity.</a> US Provisional Patent Application. , (2012).</li><li>Dylla-Spears, R., Wong, L., Miller, P., Feit, M., Steele, R., Suratwala, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Charged+Micelle+Halo+Mechanism+for+Agglomeration+Reduction+in+Metal+Oxide+Particle+Based+Polishing+Slurries.">Charged Micelle Halo Mechanism for Agglomeration Reduction in Metal Oxide Particle Based Polishing Slurries.</a> Colloid Surface A. 447, 32-43 (2014).</li><li>Wong, L., Suratwala, T., Feit, M., Miller, P., Steele, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Effect+of+HF/NH4F+Etching+on+the+Morphology+of+Surface+Fractures+on+Fused+Silica.">The Effect of HF/NH4F Etching on the Morphology of Surface Fractures on Fused Silica.</a> J. Non-Crystal. Solids. 355, 797 (2009).</li><li>Feit, M., DesJardin, R., Steele, R., Suratwala, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optimized+pitch+button+blocking+for+polishing+high-aspect-ratio+optics.">Optimized pitch button blocking for polishing high-aspect-ratio optics.</a> Appl. Opt. 51 (35), 8350-8359 (2013).</li><li>Suratwala, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sub-surface+mechanical+damage+distributions+during+grinding+of+fused+silica.">Sub-surface mechanical damage distributions during grinding of fused silica.</a> J. Non-Crystal. Solids. 352, 5601 (2006).</li><li>Miller, 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=The+Distribution+of+Sub-surface+Damage+in+Fused+Silica.">The Distribution of Sub-surface Damage in Fused Silica.</a> SPIE. 5991, (2005).</li><li>Suratwala, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+Rogue+particles+on+the+sub-surface+damage+of+fused+silica+during+grinding/polishing.">Effect of Rogue particles on the sub-surface damage of fused silica during grinding/polishing.</a> J. Non-Crystal. 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The authors have nothing to disclose.

Wie in der Einleitung erwähnt, erfolgreiche Umsetzung von Convergent Polieren auf Oberflächen- Abbildung beinhaltet beseitigt oder minimiert alle Phänomene, die räumliche Material Ungleichmäßigkeit der Ausnahme, dass der Werkstück-Runden-Fehlanpassung aufgrund der Werkstückform beeinflussen. Wenn eines dieser Phänomene nicht entsprechend vermindert, sei es durch Prozesssteuerung oder durch entsprechende Konstruktion des Polierer, dann kann der gewünschte Konvergenzpunkt nicht erreicht oder beibehalten werden k...

Die wichtigsten Schritte in einem typischen optischen Herstellungsprozess gehören Formung, Schleifen, Polieren voller Öffnung, und manchmal kleine Werkzeugpolier 1-3. Mit zunehmender Nachfrage nach qualitativ hochwertigen optischen Komponenten für die Bildgebung und Lasersysteme, gab es bedeutende Fortschritte in der optischen Fertigung in den letzten Jahrzehnten. Zum Beispiel, Präzision, ist deterministisch Materialabtrag möglich bei der Formgebung und Schleifprozesse mit Fortschritten in der Computer Numerical Controlled (CNC) Glasformmaschinen. Ebenso kleines Tool Polieren Technologien (zB computergesteuerte optische Oberflächen (CCOS), Ionen herauszufinden, und magneto-rheologischen Endbearbeitung (MRF)) haben, um determinis Materialabtrag und Oberflächen mit Kontroll-LED, so stark beeinflussen die optische Fertigungsindustrie. Doch der Zwischenschritt des Fertigungsprozesses, voller Öffnung Polieren, fehlt immer noch hohen Determinismus erfordern in der Regel Fach opticians für die Durchführung mehrerer, oft lang, iterativen Zyklen mit mehreren Prozessänderungen auf die gewünschte Oberfläche Abbildung 1-3 zu erreichen. Die große Anzahl von Polierverfahren, Prozessvariablen und die komplexen chemischen und mechanischen Wechselwirkungen zwischen dem Werkstück, Runden- und Gülle 4.3 machen es schwierig, optische Polieren von einer &quot;Kunst&quot; zu einer Wissenschaft zu verwandeln. Deterministische voller Öffnung Polieren erreichen, muss die Abtragsleistung gut verstanden werden. Historisch gesehen hat Abtragsleistung durch die weit verbreitete Preston Gleichung 5 beschrieben worden <img alt="Gleichung 1" fo:content-width="1in" fo:src="/files/ftp_upload/51965/51965eqn1.jpg" src="/files/ftp_upload/51965/51965eqn1.jpg" width="100px" /> (1) wo dh / dt ist die durchschnittliche Dicke Abtragsleistung ist, k p die Preston Konstante σ o ISder ausgeübte Druck und V r der durchschnittliche Relativgeschwindigkeit zwischen dem Werkstück und dem Schoß. Abbildung 1 zeigt schematisch die physikalischen Konzepte, die Abtragsleistung beeinflussen, wie beschrieben, die Preston-Gleichung, einschließlich räumlichen und zeitlichen Schwankungen in Geschwindigkeit und Druck, Unterschiede zwischen den aufgebrachten Druck und die Druckverteilung, die der Werkstück Erfahrungen und Reibungseffekte 8.6. Insbesondere wird die tatsächliche Druckverteilung durch das Werkstück erfahrene durch eine Reihe von Phänomenen, die stark beeinflussen resultierende Oberfläche Gestalt des Werkstücks (an anderer Stelle ausführlich beschrieben 6-8) geregelt. Auch in der Preston-Gleichung, die mikroskopische und molekularNiveauEffekte weitgehend in die makroskopische Preston Konstante (k p), welche die Gesamt Abtragsleistung Mikrorauhigkeit und sogar Kratzer an dem Werkstück beeinflußt gefaltet. Verschiedene Studien haben Prestons Modell erweitert, um Konto<html> zur mikroskopischen Partikelschlamm-pad-Werkstück-Interaktionen zu erklären, Abtragsleistung und Mikrorauhigkeit 9-16. Deterministische Kontrolle der Oberflächenfigur bei voller Öffnung Polieren zu erreichen, jede der oben beschriebenen Phänomene verstanden werden muss, quantifiziert und gesteuert. Die Strategie hinter Convergent Polieren zu beseitigen oder die unerwünschten Ursachen ungleichmäßigen Abtrag minimieren, entweder durch technische Polierer Entwurf oder durch Prozesssteuerung, so dass das Entfernen nur von dem Werkstück-Lap Fehlanpassung aufgrund der Werkstückform angetrieben 7,17- 18. 2 zeigt, wie Werkstückform, um die Konvergenz auf der Basis des Werkstück-Lap Mismatch Konzept führen. Stellen Sie sich eine flache Schoß und eine hypothetische Werkstück von oben links gezeigt komplexe Form. Die Schnittstelle Höhenübereinstimmung (die als die Lücke &amp; Dgr; h oL genannt) beeinflusst die Schnittstelle Druckverteilung (σ) als: Inhalt &quot;fo: keep-together.within-page =&quot; always &quot;&gt; <img alt="Gleichung 2" fo:content-width="1in" fo:src="/files/ftp_upload/51965/51965eqn2.jpg" src="/files/ftp_upload/51965/51965eqn2.jpg" width="100px" /> (2) wobei H eine Konstante beschreibt die Geschwindigkeit, mit der der Druck nimmt mit einer Zunahme der Spalt &amp; Delta; h oL 6. In diesem Beispiel hat das Werkstück die höchste lokale Druck in der Mitte (siehe unten links in 2), und damit diese Stelle die höchste anfängliche Abtrag während des Polierens zu beobachten. Als Material entfernt wird, wird die Druckdifferenz über das Werkstück zu einer Abnahme in dem Werkstück-Lap Fehlanpassung zu verringern durch, und das Werkstück wird an die Form des Überlappungs konvergieren. Bei der Konvergenz, dem Werkstück Druckverteilung und damit Materialentfernung wird über das Werkstück gleichmäßig sein (siehe rechte Seite der Abbildung 2). Dieses Beispiel ist für eine flache Runde dargestellt, however gilt das gleiche Konzept für ein Kugelrunde (entweder konkav oder konvex). Auch hier funktioniert diese Konvergenzprozess nur dann, wenn alle anderen Phänomene beeinflussen räumliche Material Ungleichmäßigkeit wurden eliminiert. Die spezifische Verfahrenstechnik und Minderungen in der Convergent Polieren Protokoll implementiert werden in der Diskussion beschrieben. Die in der folgenden Studie beschriebenen Protokoll ist die konvergente Polierprozess, der speziell für eine 26,5 cm im Quadrat Quarzglas Werkstück ausgehend von einem fein geschliffenen Oberfläche. In 8 Stunden Polieren (4 Stunden / Oberfläche), kann dieses Werkstück eine Flachheit der polierten ~ λ / 2 mit einer sehr hohen Oberflächenqualität (dh geringe Kratzdichte) zu erzielen.

<table border="0" cellpadding="0" cellspacing="0" width="634">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:251px;">Name of Material/Equipment</td>
			<td style="width:245px;">Company</td>
			<td style="width:139px;">Catalog Number</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">MHN 50 mil Polyurethane Pad&#160;</td>
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			<td>PF-MHN15A050L-56</td>
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			<td height="21" style="height:21px;">Cerium oxide polishing slurry</td>
			<td>Universal Photonics</td>
			<td>HASTILITE PO</td>
		</tr>
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			<td dir="LTR" height="21" style="height:21px;width:251px;">Septum Glass (waterjet cut)</td>
			<td dir="LTR" style="width:245px;">Borofloat ; Schott&#160;</td>
			<td dir="LTR" style="width:139px;">NA</td>
		</tr>
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			<td height="21" style="height:21px;">Diamond conditioner</td>
			<td>Morgan Advanced Ceramics&#160;</td>
			<td>CMP-25035-SFT</td>
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			<td>URC4</td>
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			<td>3M</td>
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</table>

convergent polishing: a simple, rapid, full aperture polishing process of high quality optical flats &amp; spheres

Convergent Polieren ist eine neue Poliersystem und ein Verfahren zur Veredelung flacher und sphärischer Glasoptik in dem ein Werkstück unabhängig von seiner ursprünglichen Form (dh Oberfläche Abbildung), werden bis zur endgültigen Oberflächenfigur mit exzellenter Oberflächenqualität unter einer festen, unveränderlichen Satz konvergieren Polierparameter in einer einzigen Polier Iteration. Im Gegensatz dazu herkömmliche voller Öffnung Polierverfahren benötigen mehrere, oft lang, iterativen Zyklen mit Polieren, Messtechnik und Prozessänderungen, um die gewünschte Oberflächenfigur zu erreichen. Die konvergente Poliervorgang basiert auf dem Konzept der Werkstück-Rundenhöhe Missverhältnis, was zu Druckdifferenz, die mit der Entfernung und führt zu dem Werkstück zusammenlaufen, um die Form der Runde sinkt basiert. Die erfolgreiche Durchführung der Convergent Polierverfahren ist ein Ergebnis der Kombination einer Anzahl von Technologien, alle Quellen von ungleichmäßigen räumlichen Materialabtrag (außer Werkstück-Runde zu entfernenMismatch) für Oberflächen mit Konvergenz und um die Anzahl der Schurken Teilchen im System für geringe Kratzdichten und geringe Rauigkeit zu reduzieren. Die konvergente Polierprozess ist für die Herstellung der beiden Wohnungen und Kugeln in verschiedenen Formen, Größen und Seitenverhältnissen auf verschiedenen Glasmaterialien nachgewiesen. Die praktischen Auswirkungen ist, dass qualitativ hochwertige optische Komponenten können schneller mehr wiederholt hergestellt werden, mit weniger Messtechnik, und mit weniger Arbeit, was zu geringeren Stückkosten. In dieser Studie wird die Convergent Polieren Protokoll speziell für die Herstellung von 26,5 cm im Quadrat zu einem poliert ~ λ / 2 Oberflächenfigur nach dem Polieren von 4 Stunden pro Fläche auf einem 81 cm Durchmesser Polier Quarzglas Wohnungen von einem feinen Bodenoberfläche beschrieben.

Die oben beschriebene Polierung Convergent-Protokoll ermöglicht eine Masse Quarzglas Werkstück (in diesem Fall eine 26,5 cm im Quadrat) poliert werden, in einem einzigen Durchlauf von 4 h pro Fläche auf eine Spitze-zu-Tal-Ebenheit von ~ λ / 2 (~ 330 nm) mit niedrigem Seitenverhältnis Werkstücke und ~ 1λ (~ 633 nm) für hohen Aspektverhältnis von Werkstücken (siehe Abbildung 3). Auch hier wiederholt konvergiert dieses Verfahren Werkstücke auf die gleiche endgültige Oberflächen Figur ohne Änd...

Watch this Scientific Journal Video about Convergent Polishing: A Simple, Rapid, Full Aperture Polishing Process of High Quality Optical Flats & Spheres at JoVE.com

Convergent Polishing: A Simple, Rapid, Full Aperture Polishing Process of High Quality Optical Flats &amp; Spheres

A novel optical polishing process, called &#8220;Convergent Polishing&#8221;, which enables faster, lower cost polishing, is described. Unlike conventional polishing processes, Convergent Polishing allows a glass workpiece to be polished in a single iteration and with high surface quality to its final surface figure without requiring changes to polishing parameters.

Convergent Polieren: Eine einfache und schnelle, Schmalrandpolierprozess der Hochwertiges optisches Wohnungen &amp; Spheres

Convergent Polishing is a novel polishing system and method for finishing flat and spherical glass optics in which a workpiece, independent of its initial ...

convergent-polishing-simple-rapid-full-aperture-polishing-process

Research

JoVE Journal

Engineering

11.0K Aufrufe.  Lawrence Livermore National Laboratory. A novel optical polishing process, called “Convergent Polishing”, which enables faster, lower cost polishing, is described. Unlike conventional polishing processes, Convergent Polishing allows a glass workpiece to be polished in a single iteration and with high surface quality to its final surface figure without requiring changes to polishing parameters.

Serie: Convergent Polishing: A Simple, Rapid, Full Aperture Polishing Process of High Quality Optical Flats & Spheres

Fabrication of Silica Ultra High Quality Factor Microresonators

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

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

Herstellung von Silica Ultra High Quality Factor Mikroresonatoren

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

Forschung

Ingenieurwesen

Process of Making Three-dimensional Microstructures using Vaporization of a Sacrificial Component

Vascular structures in natural systems are able to provide high mass transport through high surface areas and optimized structure. Few synthetic material fabrication techniques are able to mimic the complexity of these structures while maintaining scalability. The Vaporization of a Sacrificial Component (VaSC) process is able to do so. This process uses sacrificial fibers as a template to form hollow, cylindrical microchannels embedded within a matrix. Tin (II) oxalate (SnOx) is embedded within poly(lactic) acid (PLA) fibers which facilitates the use of this process. The SnOx catalyzes the depolymerization of the PLA fibers at lower temperatures. The lactic acid monomers are gaseous at these temperatures and can be removed from the embedded matrix at temperatures that do not damage the matrix. Here we show a method for aligning these fibers using micromachined plates and a tensioning device to create complex patterns of three-dimensionally arrayed microchannels. The process allows the exploration of virtually any arrangement of fiber topologies and structures.

The Vaporization of a Sacrificial Component (VaSC) process is used to fabricate microvascular structures. This procedure uses sacrificial poly(lactic) acid fibers to form hollow microchannels with precise 3D geometric positioning provided by laser micromachined guide plates.

Verfahren zur Herstellung von dreidimensionalen Mikrostrukturen mit Verdampfung eines Opferbauteil

Vascular structures in natural systems are able to provide high mass transport through high surface areas and optimized structure. Few synthetic material ...

Construction of a High Resolution Microscope with Conventional and Holographic Optical Trapping Capabilities

High resolution microscope systems with optical traps allow for precise manipulation of various refractive objects, such as dielectric beads 1 or cellular organelles 2,3, as well as for high spatial and temporal resolution readout of their position relative to the center of the trap. The system described herein has one such "traditional" trap operating at 980 nm. It additionally provides a second optical trapping system that uses a commercially available holographic package to simultaneously create and manipulate complex trapping patterns in the field of view of the microscope 4,5 at a wavelength of 1,064 nm. The combination of the two systems allows for the manipulation of multiple refractive objects at the same time while simultaneously conducting high speed and high resolution measurements of motion and force production at nanometer and piconewton scale.

The system described herein employs a traditional optical trap as well as an independent holographic optical trapping line, capable of creating and manipulating multiple traps. This allows for the creation of complex geometric arrangements of refractive particles while also permitting simultaneous high-speed, high-resolution measurements of the activity of biological enzymes.

Bau einer Hohe Auflösung Mikroskop mit Konventionelle und Holographic Optical Trapping Capabilities

High resolution microscope systems with optical traps allow for precise manipulation of various refractive objects, such as dielectric beads 1 or cellular ...

The Generation of Higher-order Laguerre-Gauss Optical Beams for High-precision Interferometry

Thermal noise in high-reflectivity mirrors is a major impediment for several types of high-precision interferometric experiments that aim to reach the standard quantum limit or to cool mechanical systems to their quantum ground state. This is for example the case of future gravitational wave observatories, whose sensitivity to gravitational wave signals is expected to be limited in the most sensitive frequency band, by atomic vibration of their mirror masses. One promising approach being pursued to overcome this limitation is to employ higher-order Laguerre-Gauss (LG) optical beams in place of the conventionally used fundamental mode. Owing to their more homogeneous light intensity distribution these beams average more effectively over the thermally driven fluctuations of the mirror surface, which in turn reduces the uncertainty in the mirror position sensed by the laser light.
We demonstrate a promising method to generate higher-order LG beams by shaping a fundamental Gaussian beam with the help of diffractive optical elements. We show that with conventional sensing and control techniques that are known for stabilizing fundamental laser beams, higher-order LG modes can be purified and stabilized just as well at a comparably high level. A set of diagnostic tools allows us to control and tailor the properties of generated LG beams. This enabled us to produce an LG beam with the highest purity reported to date. The demonstrated compatibility of higher-order LG modes with standard interferometry techniques and with the use of standard spherical optics makes them an ideal candidate for application in a future generation of high-precision interferometry.

Large laser-interferometers are being constructed to create a new type of astronomy based on gravitational waves. Their sensitivities, as for many other high-precision experiments, are approaching fundamental noise limits such as the atomic vibration of their components. We are pioneering technologies to overcome these limits using novel laser beam shapes.

Die Generation von höherer Ordnung Laguerre-Gauss optischen Strahlen für Präzisions-Interferometrie

Thermal noise in high-reflectivity mirrors is a major impediment for several  types of high-precision interferometric experiments that aim to reach the  ...

Fabrication Process of Silicone-based Dielectric Elastomer Actuators

This contribution demonstrates the fabrication process of dielectric elastomer transducers (DETs). DETs are stretchable capacitors consisting of an elastomeric dielectric membrane sandwiched between two compliant electrodes. The large actuation strains of these transducers when used as actuators (over 300% area strain) and their soft and compliant nature has been exploited for a wide range of applications, including electrically tunable optics, haptic feedback devices, wave-energy harvesting, deformable cell-culture devices, compliant grippers, and propulsion of a bio-inspired fish-like airship. In most cases, DETs are made with a commercial proprietary acrylic elastomer and with hand-applied electrodes of carbon powder or carbon grease. This combination leads to non-reproducible and slow actuators exhibiting viscoelastic creep and a short lifetime. We present here a complete process flow for the reproducible fabrication of DETs based on thin elastomeric silicone films, including casting of thin silicone membranes, membrane release and prestretching, patterning of robust compliant electrodes, assembly and testing. The membranes are cast on flexible polyethylene terephthalate (PET) substrates coated with a water-soluble sacrificial layer for ease of release. The electrodes consist of carbon black particles dispersed into a silicone matrix and patterned using a stamping technique, which leads to precisely-defined compliant electrodes that present a high adhesion to the dielectric membrane on which they are applied.

This manuscript shows the fabrication process for the manufacture of dielectric elastomer soft actuators based on silicone membranes. The three key stages of production are presented in detail: blade casting of thin silicone membranes; pad printing of compliant electrodes; and the assembly of all the components.

Herstellungsverfahren einer Silikonbasis Dielectric Elastomer Actuators

This contribution demonstrates the fabrication process of dielectric elastomer transducers (DETs). DETs are stretchable capacitors consisting of an ...

Adsorption Device Based on a Langatate Crystal Microbalance for High Temperature High Pressure Gas Adsorption in Zeolite H-ZSM-5

We present a high-temperature and high-pressure gas adsorption measurement device based on a high-frequency oscillating microbalance (5 MHz langatate crystal microbalance, LCM) and its use for gas adsorption measurements in zeolite H-ZSM-5. Prior to the adsorption measurements, zeolite H-ZSM-5 crystals were synthesized on the gold electrode in the center of the LCM, without covering the connection points of the gold electrodes to the oscillator, by the steam-assisted crystallization (SAC) method, so that the zeolite crystals remain attached to the oscillating microbalance while keeping good electroconductivity of the LCM during the adsorption measurements. Compared to a conventional quartz crystal microbalance (QCM) which is limited to temperatures below 80 &#176;C, the LCM can realize the adsorption measurements in principle at temperatures as high as 200-300 &#176;C (i.e., at or close to the reaction temperature of the target application of one-stage DME synthesis from the synthesis gas), owing to the absence of crystalline-phase transitions up to its melting point (1,470 &#176;C). The system was applied to investigate the adsorption of CO2, H2O, methanol and dimethyl ether (DME), each in the gas phase, on zeolite H-ZSM-5 in the temperature and pressure range of 50-150 &#176;C and 0-18 bar, respectively. The results showed that the adsorption isotherms of these gases in H-ZSM-5 can be well fitted by Langmuir-type adsorption isotherms. Furthermore, the determined adsorption parameters, i.e., adsorption capacities, adsorption enthalpies, and adsorption entropies, compare well to literature data. In this work, the results for CO2 are shown as an example.

A protocol for high-temperature and high-pressure gas adsorption measurements on zeolite H-ZSM-5 using an adsorption measurement device based on a langatate crystal microbalance is presented. Prior to the adsorption measurements, the synthesis of zeolite H-ZSM-5 on the langatate crystal microbalance sensor by the steam-assisted crystallization (SAC) method is demonstrated.

Adsorptionsvorrichtung Basierend auf einem Langatate Crystal Micro für Hochtemperatur-Hochdruck-Gas Adsorption in Zeolith H-ZSM-5

We present a high-temperature and high-pressure gas adsorption measurement device based on a high-frequency oscillating microbalance (5 MHz langatate ...

Challenges in Rheological Characterization of Highly Concentrated Suspensions &#8212; A Case Study for Screen-printing Silver Pastes

A comprehensive rheological characterization of highly concentrated suspensions or pastes is mandatory for a targeted product development meeting the manifold requirements during processing and application of such complex fluids. In this investigation, measuring protocols for a conclusive assessment of different process relevant rheological parameters have been evaluated. This includes the determination of yield stress, viscosity, wall slip velocity, structural recovery after large deformation and elongation at break as well as tensile force during filament stretching.
The importance of concomitant video recordings during parallel-plate rotational rheometry for a significant determination of rheological quantities is demonstrated. The deformation profile and flow field at the sample edge can be determined using appropriate markers. Thus, measurement parameter settings and plate roughness values can be identified for which yield stress and viscosity measurements are possible. Slip velocity can be measured directly and measuring conditions at which plug flow, shear banding or sample spillover occur can be identified clearly. 
Video recordings further confirm that the change in shear moduli observed during three stage oscillatory shear tests with small deformation amplitude in stage I and III but large oscillation amplitude in stage II can be directly attributed to structural break down and recovery. For the pastes investigated here, the degree of irreversible, shear-induced structural change increases with increasing deformation amplitude in stage II until a saturation is reached at deformations corresponding to the crossover of G' and G'', but the irreversible damage is independent of the duration of large amplitude shear. 
A capillary breakup elongational rheometer and a tensile tester have been used to characterize deformation and breakup behavior of highly filled pastes in uniaxial elongation. Significant differences were observed in all experiments described above for two commercial screen-printing silver pastes used for front side metallization of Si-solar cells.

Challenges in Rheological Characterization of Highly Concentrated Suspensions &amp;#8212; A Case Study for Screen-printing Silver Pastes

A protocol for a robust and application relevant rheological characterization of highly concentrated suspensions is presented. Silver pastes used for screen-printing application in solar cell production are employed as model systems.

Herausforderungen in rheologische Charakterisierung von hochkonzentrierten Suspensionen - Eine Fallstudie für Serigrafie Silberpasten

A comprehensive rheological characterization of highly concentrated suspensions or pastes is mandatory for a targeted product development meeting the ...

Method for Recording Broadband High Resolution Emission Spectra of Laboratory Lightning Arcs

Lightning is one of the most common and destructive forces in nature and has long been studied using spectroscopic techniques, first with traditional camera film methods and then digital camera technology, from which several important characteristics have been derived. However, such work has always been limited due to the inherently random and non-repeatable nature of natural lightning events in the field. Recent developments in lightning test facilities now allow the reproducible generation of lightning arcs within controlled laboratory environments, providing a test bed for the development of new sensors and diagnostic techniques to understand lightning mechanisms better. One such technique is a spectroscopic system using digital camera technology capable of identifying the chemical elements with which the lightning arc interacts, with these data then being used to derive further characteristics. In this paper, the spectroscopic system is used to obtain the emission spectrum from a 100 kA peak, 100 &#181;s duration lightning arc generated across a pair of hemispherical tungsten electrodes separated by a small air gap. To maintain a spectral resolution of less than 1 nm, several individual spectra were recorded across discrete wavelength ranges, averaged, stitched, and corrected to produce a final composite spectrum in the 450 nm (blue light) to 890 nm (near infrared light) range. Characteristic peaks within the data were then compared to an established publicly available database to identify the chemical element interactions. This method is readily applicable to a variety of other light emitting events, such as fast electrical discharges, partial discharges, and sparking in electrical equipment, apparatus, and systems.

Emission spectroscopy techniques have traditionally been used to analyze inherently random lightning arcs occurring in nature. In this paper, a method developed to obtain the emission spectroscopy from reproducible lightning arcs generated within a laboratory environment is described.

Verfahren zur Aufzeichnung von Breitband-Emissionsspektren von Laborblitzen

Lightning is one of the most common and destructive forces in nature and has long been studied using spectroscopic techniques, first with traditional ...

Atomic Layer Deposition of Vanadium Dioxide and a Temperature-dependent Optical Model

Vanadium dioxide is a material that has a reversible metal-insulator phase change near 68 &#176;C. To grow VO2 on a wide variety of substrates, with wafer-scale uniformity and angstrom level control of thickness, the method of atomic-layer deposition was chosen. This ALD process enables high-quality, low-temperature (&#8804;150 &#176;C) growth of ultrathin films (100-1000 &#197;) of VO2. For this demonstration, the VO2 films were grown on sapphire substrates. This low temperature growth technique produces mostly amorphous VO2 films. A subsequent anneal in an ultra-high vacuum chamber with a pressure of 7x10-4 Pa of ultra-high purity (99.999%) oxygen produced oriented, polycrystalline VO2 films. The crystallinity, phase, and strain of the VO2 were determined by Raman spectroscopy and X-ray diffraction, while the stoichiometry and impurity levels were determined by X-ray photoelectron spectroscopy, and finally the morphology was determined by atomic force microscopy. These data demonstrate the high-quality of the films grown by this technique. A model was created to fit to the data for VO2 in its metallic and insulating phases in the near infrared spectral region. The permittivity and refractive index of the ALD VO2 agreed well with the other fabrication methods in its insulating phase, but showed a difference in its metallic state. Finally, the analysis of the films&#39; optical properties enabled the creation of a wavelength- and temperature-dependent model of the complex optical refractive index for developing VO2 as a tunable refractive index material.

Thin films (100-1000 &#197;) of vanadium dioxide (VO2) were created by atomic-layer deposition (ALD) on sapphire substrates. Following this, the optical properties were characterized through the metal-insulator transition of VO2. From the measured optical properties, a model was created to describe the tunable refractive index of VO2.

Atomic Layer Deposition von Vanadium Kohlendioxid und eine temperaturabhängige optische Modell

Vanadium dioxide is a material that has a reversible metal-insulator phase change near 68 &#176;C. To grow VO2 on a wide variety of substrates, with ...

Predicting Catalyst Extrudate Breakage Based on the Modulus of Rupture

The mechanical strength of extruded catalysts and their natural or forced breakage by either collision against a surface or by a compressive load in a fixed bed are important phenomena in catalyst technology. The mechanical strength of the catalyst is measured here by its bending strength or flexural strength. This technique is relatively new from the perspective of applying it to commercial catalysts of typical sizes used in the industry. Catalyst breakage by collision against a surface is measured after a fall of the extrudates through the ambient air in a vertical pipe. Quantifying the impact force is done theoretically by applying Newton's second law. Measurement of catalyst breakage due to stress in a fixed bed is done following the standard procedure of the bulk crush strength test. Novel here is the focus on measuring the reduction in the length to diameter ratio of the extrudates as a function of the stress.

Here we present a protocol to measure the modulus of rupture of an extruded catalyst and the breakage of said catalyst extrudates by collision against a surface or by compression in a fixed bed.

Vorhersage Katalysator Extrudat Bruch basierend auf der e-Modul des Bruches

The mechanical strength of extruded catalysts and their natural or forced breakage by either collision against a surface or by a compressive load in a ...