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.

NOTA: effettuare tutte le seguenti operazioni sotto classe di camera bianca 100 condizioni o meglio. Preparazione 1. Campione <ol><li> Pulire un wafer di silicio 2 &quot;di diametro con la soluzione Buffered Oxide Etch (BOE) (6 pezzi 40% NH 4 F e 1 parte di 49% HF) per 2 min (Attenzione: i prodotti chimici pericolosi). Scegliere questo tempo di attacco per rimuovere eventuali sostanze organiche o contaminanti sulla superficie. Risciacquare con acqua deionizzata (DI) di acqua per circa 5 minuti. Wafer a secco con N a secco 2. NOTA: Non lavorare mai da soli quando si usa HF. Indossa sempre occhiali di protezione con visiera e dispositivi di protezione individuale (DPI) in caso di sversamenti. Le linee guida relative all&#39;uso e il trattamento dei rifiuti HF in laboratorio dove viene eseguita l&#39;incisione. NOTA: i passaggi 1,2-1,7 sono solo blocco elettrochimica. Se l&#39;esecuzione di blocco tramite dissoluzione passare al punto 2. </li><li> Per stabilire l&#39;elettrodo di lavoro, sputter 100 nm di Platino (Pt) sul pulito 2 &quot;di diametro Silicsu wafer. </li><li> Prima incisione il film sottile di platino, pulire la camera RIE di eventuali impurità o di resina fotosensibile rimasto dalle precedenti Incide secco. </li><li> Pompare giù la camera fino ad una pressione di base di 1 × 10 -5 Torr è raggiunto. Assicurarsi che la potenza RF è impostato a 200 W e le portate per l&#39;ossigeno e argon sono impostati rispettivamente a 50 e 10 SCCM SCCM. Accendere l&#39;Ar O 2 / plasma e correre per almeno 1 ora. </li><li> Spegnere l&#39;Ar O 2 / plasma e lasciare la camera di sfogo per circa 10 min. </li><li> Per etch la superficie della pellicola sottile di platino, caricare il campione nella camera di RIE e pompare la camera fino ad una pressione di base di 1 × 10 -5 Torr. Questa volta impostata la portata argon a 0 sccm. Accendere la O 2 plasma e lasciate correre questo processo per 30 min. </li><li> Spegnere la O 2 plasma e lasciare che la camera di sfogo per 10 min. </li></ol> 2. evaporazione termica di Photochromic Molecule Uso personalizzata Low evaporatore temperatura (LTE) <ol><li> Riempire AlO 2 barca con 30 mg di BTE e caricare in fonte LTE personalizzato (figura 6). </li><li> Carica wafer di silicio in campioni di montaggio. </li><li> Porti camera di tenuta e camera della pompa fino ad una pressione di base di 1 x 10 -6 Torr. </li><li> Si evapora il BTE ad una temperatura nominale di 100 ° C, con uno spessore di 30 nm. </li><li> Subito dopo l&#39;evaporazione, alluvione illuminare il campione di 5 min di UV per trasformare il materiale BTE per la forma chiusa, 1c. </li><li> Per definire la dimensione del campione, fendere un piccolo pezzo di wafer con un scrivano diamante graffiare una linea dal bordo della superficie di silicio. Afferrare il wafer su entrambi i lati della linea di zero e piegare il wafer verso il basso finché si rompe lungo il piano di cristallo. </li><li> Eseguire misurazioni profilometro per convalidare BTE spessore del film sottile. Per fare questo, graffiare il campione con una multa pinzetta bordo. Misurare l&#39;altezza del gradino from questo zero, che è la differenza di altezza tra la posizione del cursore destra e sinistra. NOTA: Le imprecisioni di spessore del film si tradurrà in discrepanze nelle dose di esposizione. </li><li> Conservare restante campione in N 2 cassetto portaoggetti riempita. </li></ol> 3. Esposizioni NOTA: Eseguire tutte le esposizioni, in condizioni atmosfera inerte per prevenire il degrado di campione. <ol><li> Cleave campione seguendo la stessa procedura descritta al punto 2.6. </li><li> Carico campione portacampioni atmosfera inerte. </li><li> Montare supporto del campione inerte sul palco. Campione Purge con N 2. </li><li> Esporre il campione al tempo di esposizione desiderata utilizzando un interferometro, come quello mostrato in Figura 8. </li></ol> 4. elettrochimica di ossidazione utilizzando tre elettrodi cellulare NOTA: Eseguire elettrochimica in condizioni atmosfera inerte per prevenire il degrado di campione. <ol><li> Bloccare una fiala di vetro pulito sulla parte superiore della piastra calda. Mettere una barra di agitazione pulita nel flacone. Accendere l&#39;agitatore. </li><li> Pulire una nuova clip di rame con metanolo. Pulire l&#39;elettrodo contatore platino con metanolo. </li><li> Utilizzando una clip di rame pulita, agganciare il campione attraverso uno dei fori del tappo flacone Teflon. Assicurarsi di agganciare solo il platino esposta. </li><li> Posizionare il tappo flacone Teflon sul flacone. Agganciare il cavo rosso sul bancone di platino elettrodo e il cavo nero sulla clip di rame che tiene il campione. </li><li> Usando una siringa pulita, riempire il flacone con acqua deionizzata filtrata (DI) di acqua attraverso il secondo foro nel tappo flacone Teflon. Riempire come alto senza immergendo qualsiasi platino nuda sul campione. </li><li> Bubble azoto attraverso l&#39;acqua per 3-5 min. Spegnere l&#39;azoto. </li><li> Inserire l&#39;elettrodo di riferimento nel secondo foro nel tappo flacone Teflon. Agganciare la biacca sulla elettrodo di riferimento. Verificare che nessuno di platino o nudon il campione è immerso. </li><li> Utilizzando un voltammograph, impostare la tensione di ossidazione a 0,5 V / sec. </li><li> Trascorso il tempo di ossidazione desiderato, disattivare l&#39;alimentazione alla voltammograph off. </li><li> Rimuovere i clips rosso, nero, bianco e dal bancone elettrodo di platino, clip di rame, ed elettrodo di riferimento. </li><li> Esporre il campione UV per 5 min. </li></ol> 5. Campione Sviluppo - Electrochemical Locking NOTA: Eseguire lo sviluppo in condizioni atmosfera inerte per prevenire il degrado di campione. <ol><li> Sviluppare il campione filtrato 5 (wt%) isopropanolo, 95 (wt%) etilene glicole per la quantità di tempo desiderato. Nota: Tipicamente 50 campioni nm sono sviluppati per 30-60 secondi, mentre 80 campioni nm sono sviluppati per 60-180 sec. </li><li> Campione secco con N a secco 2. </li><li> Esporre immediatamente campione 5 min di UV. </li></ol> 6. campione di sviluppo - Scioglimento Locking </em&gt; NOTA: Eseguire lo sviluppo in condizioni atmosfera inerte per prevenire il degrado di campione. <ol><li> Utilizzando 100 ml di glicole etilenico in un bicchiere di vetro pulito, sviluppare il campione esposto per il tempo di sviluppo desiderato. </li><li> Campione secco con N a secco 2. Esporre immediatamente campione 5 min di UV. </li></ol> 7. Alle esposizioni multiple <ol><li> Se l&#39;esecuzione di esposizioni multiple ripetere i passaggi 3-6 con una traduzione del campione rispetto alle ottiche. </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...

Litografia ottica è di fondamentale importanza nella fabbricazione di strutture in nanoscala e dei dispositivi. Aumento progressi nelle tecniche di litografia romanzo ha la possibilità di abilitare le nuove generazioni di nuovi dispositivi. 8-11 In questo articolo, una revisione è presentato di una classe di tecniche litografiche ottici che raggiungono profondità risoluzione sub-banda di frequenza con nuove molecole photoswitchable. Questo approccio è chiamato Patterning tramite Optical saturabile Transitions (POST). 1-3 POST è una nuova tecnica di nanofabbricazione, che combina in modo unico le idee di saturare transizioni ottiche di molecole fotocromatiche, in particolare (1,2-bis (5,5&#39;-dimetil-2,2&#39;-il-bithiophen)) perfluorocyclopent-1-ene. Colloquialmente, questo composto è indicato come BTE, Figura 1, come quelli utilizzati in stimolata emissioni deplezione (STED) microscopia a 12, con interferenza litografia, che lo rende un potente strumento per large-zona nanopatterning parallela di funzioni subwavelength profonde su una varietà di superfici con potenziale estensione a 2 e 3 dimensioni. Lo strato fotocromatica è originariamente in uno stato omogeneo. Quando questo strato è esposto ad una illuminazione uniforme di λ 1, converte nel secondo stato isomerica (1c), Figura 2. Poi il campione è esposto a un nodo mirato a λ 2, che converte il campione nel primo stato isomerica ( 1o) ovunque tranne nelle immediate vicinanze del nodo. Controllando la dose di esposizione, la dimensione della regione non convertito può essere arbitrariamente piccola. Una successiva fase di fissaggio di uno degli isomeri può essere selettivamente e irreversibilmente convertito (bloccato) in uno stato di 3 ° (in nero) per bloccare il pattern. Successivamente, lo strato è esposto uniformemente a λ 1, che converte tutto tranne la regione bloccata ritorna allo stato originale. Ilsequenza di fasi può essere ripetuta con uno spostamento del campione rispetto alle ottiche, con conseguente due aree bloccate cui spaziatura è inferiore al limite di diffrazione campo lontano. Pertanto, qualsiasi geometria arbitraria può essere modellato in modo &quot;aghi&quot;. 1-3

<table border="0" cellpadding="0" cellspacing="0" width="778">
	<tbody>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Name of Material/ Equipment</td>
			<td style="width:205px;">Company</td>
			<td style="width:119px;">Catalog Number</td>
			<td style="width:239px;">Comments/Description</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:216px;">Isopropanol</td>
			<td style="width:205px;">Fisher Scientific</td>
			<td style="width:119px;">P/7500/15</td>
			<td style="width:239px;">CAUTION: flammable, use good 
			ventilation and avoid all ignition 
			sources.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Buffered Oxide Etch</td>
			<td style="width:205px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:216px;">Methanol</td>
			<td style="width:205px;">Ricca Chemical</td>
			<td style="width:119px;">48-293-2&#160;</td>
			<td style="width:239px;">CAUTION: flammable, use good 
			ventilation and avoid all ignition 
			sources.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Ethylene Glycol</td>
			<td style="width:205px;">Sigma-Aldrich</td>
			<td style="width:119px;">324558</td>
			<td>CAUTION: Harmful if swallowed</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Silicon wafer</td>
			<td style="width:205px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Diamond Scribe</td>
			<td style="width:205px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Glass Beakers</td>
			<td style="width:205px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Tweezers</td>
			<td style="width:205px;">Ted Pella</td>
			<td style="width:119px;">5226</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Reactive Ion Etching System</td>
			<td style="width:205px;">Oxford</td>
			<td style="width:119px;">Plasma Lab 80 Plus</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Inert Atmosphere Sample Holder</td>
			<td style="width:205px;">Proprietary In-house Designed</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Polarizing beamsplitter cube</td>
			<td style="width:205px;">Thorlabs</td>
			<td style="width:119px;">PBS052</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">HeNe Laser</td>
			<td style="width:205px;">Melles Griot</td>
			<td style="width:119px;">25-LHP-171</td>
			<td>CAUTION: Wear safety glasses</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Half-wave plates</td>
			<td style="width:205px;">Thorlabs</td>
			<td style="width:119px;">WPH05M-633</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Thermal Evaporator</td>
			<td style="width:205px;">Proprietary In-house Designed</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">TMV Super</td>
			<td style="width:205px;">TM Vacuum Products</td>
			<td style="width:119px;">TMV Super</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Voltammograph</td>
			<td style="width:205px;">Bioanalytical Systems</td>
			<td style="width:119px;">CV-37</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Shortwave UV lamp 365nm</td>
			<td style="width:205px;">UVP Analytik Jena Company</td>
			<td style="width:119px;">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.

Campioni fabbricati: Differenti tempi di ossidazione sono stati caratterizzati come illustrato dalle micrografie a forza atomica in figura 3 con una tensione di ossidazione di 0,85 V determinata dalla voltammetria ciclica. I film di 50 nm di spessore sono stati esposti a un&#39;onda stazionaria a λ = 647 nm del periodo di 400 nm per 60 secondi ad una densità di potenza di 0.95 mW / cm 2. Poiché il tempo di ossidazione viene aumentata da 10 min ...

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.

Patterning via ottici saturabili Transitions - fabbricazione e la caratterizzazione

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

patterning-via-optical-saturable-transitions-fabrication

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6.7K 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

Simulation, Fabrication and Characterization of THz Metamaterial Absorbers

Metamaterials (MM), artificial materials engineered to have properties that may not be found in nature, have been widely explored since the first theoretical1 and experimental demonstration2 of their unique properties. MMs can provide a highly controllable electromagnetic response, and to date have been demonstrated in every technologically relevant spectral range including the optical3, near IR4, mid IR5 , THz6 , mm-wave7 , microwave8 and radio9 bands. Applications include perfect lenses10, sensors11, telecommunications12, invisibility cloaks13 and filters14,15. We have recently developed single band16, dual band17 and broadband18 THz metamaterial absorber devices capable of greater than 80% absorption at the resonance peak. The concept of a MM absorber is especially important at THz frequencies where it is difficult to find strong frequency selective THz absorbers19. In our MM absorber the THz radiation is absorbed in a thickness of ~ &lambda;/20, overcoming the thickness limitation of traditional quarter wavelength absorbers. MM absorbers naturally lend themselves to THz detection applications, such as thermal sensors, and if integrated with suitable THz sources (e.g. QCLs), could lead to compact, highly sensitive, low cost, real time THz imaging systems.

This protocol outlines the simulation, fabrication and characterization of THz metamaterial absorbers. Such absorbers, when coupled with an appropriate sensor, have applications in THz imaging and spectroscopy.

Simulazione, fabbricazione e caratterizzazione di THz Assorbitori metamateriale

Metamaterials (MM),  artificial materials engineered to have properties that may not be found in  nature, have been widely explored since the first ...

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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).

Fabbricazione e caratterizzazione di guide d&#39;onda fotoniche di cristallo di luce lenta e cavità

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 ...

Design, Fabrication, and Experimental Characterization of Plasmonic Photoconductive Terahertz Emitters

In this video article we present a detailed demonstration of a highly efficient method for generating terahertz waves. Our technique is based on photoconduction, which has been one of the most commonly used techniques for terahertz generation 1-8. Terahertz generation in a photoconductive emitter is achieved by pumping an ultrafast photoconductor with a pulsed or heterodyned laser illumination. The induced photocurrent, which follows the envelope of the pump laser, is routed to a terahertz radiating antenna connected to the photoconductor contact electrodes to generate terahertz radiation. Although the quantum efficiency of a photoconductive emitter can theoretically reach 100%, the relatively long transport path lengths of photo-generated carriers to the contact electrodes of conventional photoconductors have severely limited their quantum efficiency. Additionally, the carrier screening effect and thermal breakdown strictly limit the maximum output power of conventional photoconductive terahertz sources. To address the quantum efficiency limitations of conventional photoconductive terahertz emitters, we have developed a new photoconductive emitter concept which incorporates a plasmonic contact electrode configuration to offer high quantum-efficiency and ultrafast operation simultaneously. By using nano-scale plasmonic contact electrodes, we significantly reduce the average photo-generated carrier transport path to photoconductor contact electrodes compared to conventional photoconductors 9. Our method also allows increasing photoconductor active area without a considerable increase in the capacitive loading to the antenna, boosting the maximum terahertz radiation power by preventing the carrier screening effect and thermal breakdown at high optical pump powers. By incorporating plasmonic contact electrodes, we demonstrate enhancing the optical-to-terahertz power conversion efficiency of a conventional photoconductive terahertz emitter by a factor of 50 10.

We describe methods for the design, fabrication, and experimental characterization of plasmonic photoconductive emitters, which offer two orders of magnitude higher terahertz power levels compared to conventional photoconductive emitters.

Progettazione, fabbricazione, e Sperimentale Caratterizzazione di plasmoniche Emettitori Terahertz fotoconduttive

In this video article we present a detailed demonstration of a highly efficient method for generating terahertz waves. Our technique is based on ...

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.

Fabbricazione e caratterizzazione di polimeri disordinati fibre ottiche per la Trasversale localizzazione di Anderson di Luce

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

Fabrication of Uniform Nanoscale Cavities via Silicon Direct Wafer Bonding

Measurements of the heat capacity and superfluid fraction of confined 4He have been performed near the lambda transition using lithographically patterned and bonded silicon wafers. Unlike confinements in porous materials often used for these types of experiments3, bonded wafers provide predesigned uniform spaces for confinement. The geometry of each cell is well known, which removes a large source of ambiguity in the interpretation of data.
Exceptionally flat, 5 cm diameter, 375 &#181;m thick Si wafers with about 1 &#181;m variation over the entire wafer can be obtained commercially (from Semiconductor Processing Company, for example). Thermal oxide is grown on the wafers to define the confinement dimension in the z-direction. A pattern is then etched in the oxide using lithographic techniques so as to create a desired enclosure upon bonding. A hole is drilled in one of the wafers (the top) to allow for the introduction of the liquid to be measured. The wafers are cleaned2 in RCA solutions and then put in a microclean chamber where they are rinsed with deionized water4. The wafers are bonded at RT and then annealed at ~1,100 &#176;C. This forms a strong and permanent bond. This process can be used to make uniform enclosures for measuring thermal and hydrodynamic properties of confined liquids from the nanometer to the micrometer scale.

A method for permanently bonding two silicon wafers so as to realize a uniform enclosure is described. This includes wafer preparation, cleaning, RT bonding, and annealing processes. The resulting bonded wafers (cells) have uniformity of enclosure ~1%1,2. The resulting geometry allows for measurements of confined liquids and gasses.

Fabbricazione di cavità uniformi su nanoscala tramite silicon direct wafer bonding

Measurements of the heat capacity and superfluid fraction of confined 4He have been performed near the lambda transition using lithographically patterned ...

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.

Fabbricazione e funzionamento di un nano-ottica Nastro trasportatore

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

Compact Lens-less Digital Holographic Microscope for MEMS Inspection and Characterization

A micro-electro-mechanical-system (MEMS) is a widely used component in many industries, including energy, biotechnology, medical, communications, and automotive. However, effective inspection and characterization metrology systems are needed to ensure the functional reliability of MEMS. This study presents a system based on digital holography as a tool for MEMS metrology. Digital holography has gained increasing attention in the past 20 years. With the fast development and decreasing cost of sensor arrays, resolution of such systems has increased broadening potential applications. Thus, it has attracted attention from both research and industry sides as a potential reliable tool for industrial metrology. Indeed, by recording the interference pattern between an object beam (which contains sample height information) and a reference beam on a CCD camera, one can retrieve the quantitative phase information of an object. However, most of digital holographic systems are bulky and thus not easy to implement on industry production lines. The novelty of the system presented is that it is lens-less and thus very compact. In this study, it is shown that the Compact Digital Holographic Microscope (CDHM) can be used to evaluate several characteristics typically consider as criteria in MEMS inspections. The surface profiles of MEMS in both static and dynamic conditions are presented. Comparison with AFM is investigated to validate the accuracy of the CDHM.

We present a compact reflection digital holographic system (CDHM) for inspection and characterization of MEMS devices. A lens-less design using a diverging input wave providing natural geometrical magnification is demonstrated. Both static and dynamic studies are presented.

Lens-meno compatta digitale olografico microscopio per MEMS di ispezione e caratterizzazione

A micro-electro-mechanical-system (MEMS) is a widely used component in many industries, including energy, biotechnology, medical, communications, and ...

Printing Fabrication of Bulk Heterojunction Solar Cells and In Situ Morphology Characterization

Polymer-based materials hold promise as low-cost, flexible efficient photovoltaic devices. Most laboratory efforts to achieve high performance devices have used devices prepared by spin coating, a process that is not amenable to large-scale fabrication. This mismatch in device fabrication makes it difficult to translate quantitative results obtained in the laboratory to the commercial level, making optimization difficult. Using a mini-slot die coater, this mismatch can be resolved by translating the commercial process to the laboratory and characterizing the structure formation in the active layer of the device in real time and in situ as films are coated onto a substrate. The evolution of the morphology was characterized under different conditions, allowing us to propose a mechanism by which the structures form and grow. This mini-slot die coater offers a simple, convenient, material efficient route by which the morphology in the active layer can be optimized under industrially relevant conditions. The goal of this protocol is to show experimental details of how a solar cell device is fabricated using a mini-slot die coater and technical details of running in situ structure characterization using the mini-slot die coater.

Printing Fabrication of Bulk Heterojunction Solar Cells and In Situ Morphology Characterization

Here, we present a protocol to fabricate organic thin film solar cells using a mini-slot die coater and related in-line structure characterizations using synchrotron scattering techniques.

La stampa Fabbricazione di massa eterogiunzione celle solari e<em&gt; In Situ</em&gt; Morfologia Caratterizzazione

Polymer-based materials hold promise as low-cost, flexible efficient photovoltaic devices. Most laboratory efforts to achieve high performance devices ...

Fabrication and Characterization of Superconducting Resonators

Superconducting microwave resonators are of interest for a wide range of applications, including for their use as microwave kinetic inductance detectors (MKIDs) for the detection of faint astrophysical signatures, as well as for quantum computing applications and materials characterization. In this paper, procedures are presented for the fabrication and characterization of thin-film superconducting microwave resonators. The fabrication methodology allows for the realization of superconducting transmission-line resonators with features on both sides of an atomically smooth single-crystal silicon dielectric. This work describes the procedure for the installation of resonator devices into a cryogenic microwave testbed and for cool-down below the superconducting transition temperature. The set-up of the cryogenic microwave testbed allows one to do careful measurements of the complex microwave transmission of these resonator devices, enabling the extraction of the properties of the superconducting lines and dielectric substrate (e.g., internal quality factors, loss and kinetic inductance fractions), which are important for device design and performance.

Superconducting microwave resonators are of interest for detection of light, quantum computing applications and materials characterization. This work presents a detailed procedure for fabrication and characterization of superconducting microwave resonator scattering parameters.

Fabbricazione e caratterizzazione di superconduttori risonatori

Superconducting microwave resonators are of interest for a wide range of applications, including for their use as microwave kinetic inductance detectors ...

Fabrication of Polymer Microspheres for Optical Resonator and Laser Applications

This paper describes three methods of preparing fluorescent microspheres comprising &#960;-conjugated or non-conjugated polymers: vapor diffusion, interface precipitation, and mini-emulsion. In all methods, well-defined, micrometer-sized spheres are obtained from a self-assembling process in solution. The vapor diffusion method can result in spheres with the highest sphericity and surface smoothness, yet the types of the polymers able to form these spheres are limited. On the other hand, in the mini-emulsion method, microspheres can be made from various types of polymers, even from highly crystalline polymers with coplanar, &#960;-conjugated backbones. The photoluminescent (PL) properties from single isolated microspheres are unusual: the PL is confined inside the spheres, propagates at the circumference of the spheres via the total internal reflection at the polymer/air interface, and self-interferes to show sharp and periodic resonant PL lines. These resonating modes are so-called "whispering gallery modes" (WGMs). This work demonstrates how to measure WGM PL from single isolated spheres using the micro-photoluminescence (&#181;-PL) technique. In this technique, a focused laser beam irradiates a single microsphere, and the luminescence is detected by a spectrometer. A micromanipulation technique is then used to connect the microspheres one by one and to demonstrate the intersphere PL propagation and color conversion from coupled microspheres upon excitation at the perimeter of one sphere and detection of PL from the other microsphere. These techniques, &#181;-PL and micromanipulation, are useful for experiments on micro-optic application using polymer materials.

Protocols for the synthesis of microspheres from polymers, the manipulation of microspheres, and micro-photoluminescence measurements are presented.