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1. Optik Sistem Kurulumu (Şekil 1) <ol><li> Bir yarım dalga plakası ve lazer atış enerjisi ayarlamak için lazer çıkışı izleyen bir polarize ayarlayın. </li><li> Pompa nabız ve prob darbe: iki pulse lazer darbe bölmek için polarize sonra bir demeti splitter kurun. </li><li> Pompa darbe için bir optik gecikme aracı inşa etmek için dört yansıtan aynalar ve manuel translasyonel sahne kullanın. </li><li> Dikey hedef yüzey ulaşmak için pompa darbe rehberlik başka dört yansıtan ayna kullanın. </li><li> 800 nm ile 400 nm dalga boyunda lazer sinyali dönüştürmek için ikinci bir harmonik üreteci (SHG) ayarlayın. </li><li> 800-nm darbe iletimi ve 400 nm darbe yansıtmak için harmonik bir ayırıcı kullanılır. </li><li> Bir kiriş azaltıcı ve prob puls büyüklüğü ve konverjans ayarlamak için fokal lensler bir çift ayarlayın. </li><li> Prob darbe gibi Adım 1.3 &#39;de belirtilen başka bir optik gecikme aracı, ayarlayın. </li><li> Alanında ayarlamak için bir İris halkası kullanınprob nabız ve prob darbe yatay hedef yüzey geçmek ve pompa darbe ile kesişir emin olun. </li><li> Yoğun şarj kuplajlı cihaz (ICCD) kamera tarafından alınacak plazma bölgenin görüntü oluşturmak için iki objektif lens ve çeşitli filtreler ayarlama. </li><li> Bilgisayar, lazer, ICCD kamera ve BNC kablo veya USB kablosu kullanarak denetleyici bağlayın. </li><li> Kamera prob darbe bir görüntü yakalar kadar kamera kontrol gecikme süresini ayarlayın. Böylece, prob nabız ve kamera eşitlenir. </li></ol> 2. Pompa-probe Senkronizasyon <ol><li> Pompa nabız ve prob darbe kesiştiği bir ışın ayırıcı yerleştirin ve bu iki darbe almak için iki fotodiyotlar kurmak. Bu iki fotodiyotlar uzak demeti splitter bir aynı mesafede olmalıdır. </li><li> Bu iki fotodiyotlara sinyalleri almak için bir osiloskop kullanın ve pro kadar pompa darbe ışın yolu üzerindeki gecikme sahne hareketPompa nabız ve prob darbe dosyaları osiloskop ekranından birbirleri ile örtüşmektedir. 20 ps bir doğruluk osiloskop temporal çözünürlük sayesinde elde edilir. </li><li> Demeti splitter ve gibi Adım 2.1 &#39;de belirtilen iki fotodiyotlar çıkarın. </li><li> Hava dökümü bölgede sadece ICCD ekranda görülebiliyor kadar pompa darbe ışın yolu üzerindeki gecikme sahne ayarlayın. Hava arıza oluşumu düzgün bir arka plan yerine tespit edilebilir gecikme zamanı sıfır olarak belirlenmiştir. </li></ol> 3. Numune ve Sahne Hazırlama <ol><li> Özgürlük üç derece ile örnek hareket için bir laboratuar-jack ve iki doğrusal kılavuzu aşamada ayarlayın. </li><li> Aşamalarında yüksek bir düzlük elde etmek için bir kadran göstergesi ve yüksek hassasiyetli levhaları kullanın. Yükseklik farkı 25.4 mm&#39;lik bir mesafe başına 1 mikron arasında olmalıdır. </li><li> Bir freze ile 0.8 mm kalınlığında bir bakır levha dışında bir kare parçası (30 mm x 30 mm) Cutmakine. </li><li> Yüzey pürüzlülüğü altında 0,5 mikron kadar Cu parçasının dar tarafı (30 mm x 0,8 mm) parlatın. </li><li> Cilalı dar yüzü ile üst manuel sahnede Cu parça Fix. </li><li> Herhangi bir eğim hedefin altında yüksek hassasiyet şim ekleyerek ayarlanabilmektedir böyle ICCD kamera ile konumunu izlemek ise Adım 3.1) da belirttiğim gibi tek elle aşama hedef taşıyın. </li><li> Diğer manuel sahne ile Adım 3.6 tekrarlayın. </li><li> Üçüncü bir yüksek doğruluk manuel aşama odak lens pozisyonu değişir iken hedef delik bir düzine delin. Odak noktası konumu küçük delik delinmiştir edilir merceğin odak konumuna karşılık gelir. </li></ol> 4. Ablasyon ve Ölçme <ol><li> Kadar uzakta odak noktasından yaklaşık 50 um bir mesafe odaklı lens taşıyın. </li><li> Ya, 10 ps kadar görüntü her 2 ps yakalamak için 0,3 mm ara ile prob darbe ışın yolu üzerindeki gecikme sahne taşıyın480 ps kadar görüntü her 20 ps yakalamak için 3 mm ara ile. </li><li> Tekrarlanabilirlik ve doğruluk için birkaç kez Adım 4.2 tekrarlayın. </li><li> Uzaklıkta odak noktasından yaklaşık 50 mikron mesafeye odak lensi aşağı taşıma ve Adım 4.3 tekrarlayın. </li></ol> 5.. Temsilcisi Sonuçlar Ölçülen shadowgraph görüntü şekil gösterilmektedir. 2 ve Şek. 3, sırasıyla, hafif hedef yüzey üstünde ve altında odak noktası için. Longitudinal ve radyal genişleme pozisyonları Şekil çizilir. 4 ve Şek. 5.. İlk 100 PS, bu durumda iki uzunlamasına açılımlar önemli ölçüde farklı olan, ancak aşağıdaki 400 PS ve radyal açılımlar kendi uzunlamasına açılımlar benzerdir. İlk durumda, 100 PS içinde erken plazma birden fazla katmandan oluşan tek boyutlu bir genişletme bir yapıya sahiptir. İkinci durumda, erken pl içinasma 100 ps içinde çok fazla değişmez iki boyutlu bir genişleme yapısı vardır. Simülasyon modeli 12 erken plazma evrim mekanizması araştırmak için kullanılır. Zaman sıfır lazer darbeli pik hedef yüzey ulaştığı zaman olarak tanımlanmaktadır. Şekil olarak simüle erken plazma gelişim süreçleri, bu iki olgunun her iki ölçüm sonuçları ile de katılıyorum. 6 ve Şek. Sırasıyla, 7,. 1 PS içinde erken plazma oluşumunu da simülasyon modeli kullanılarak ilk durum için öngörülen ve Şek. 8. Erken bir hava plazma dökümü bölge ve bir Cu plazma bölgeye sahip olduğu tespit edilmektedir. Hava dökümü ilk multi-foton iyonizasyon neden ve sonra çığ iyonizasyon takip eder. İkinci durumda, bununla birlikte, odak noktasının altında hedef yüzey ve ayrı bir hava dökümü bölgesi oluşturulur. Bunun yerine, hava iyonlaşma Cu pla yakın oluşursma ön ve Cu hedef salınan serbest elektron etkisi nedeniyle iyonizasyon neden olur. <img alt="Şekil 1" src="/files/ftp_upload/4033/4033fig1.jpg" /> Şekil 1. Pompa-sonda shadowgraph ölçümü şematik. <img alt="Şekil 2" src="/files/ftp_upload/4033/4033fig2.jpg" /> Biraz yüzey üzerinde odak noktasına sahip ardışık gecikme süreleri de Şekil 2. Cu plazma genişlemesi. Lazer dalga boyu: 800 nm; darbe süresi: 100 fs; güç yoğunluğu: 4.2 × 10 14 W / cm 2; hedef: Cu. <img alt="Şekil 3" src="/files/ftp_upload/4033/4033fig3.jpg" /> Biraz yüzeyin altında odak noktasına sahip ardışık gecikme süreleri de Şekil 3. Cu plazma genişlemesi. Lazer dalga boyu: 800 nm; darbe süresi: 100 fs; güç yoğunluğu: 4.2 × 10 14 W / cm 2; hedef: Cu. &lt;img alt = &quot;Şekil 4&quot; src = &quot;/ files/ftp_upload/4033/4033fig4.jpg&quot; /&gt; Şekil 4. Plazma uzunlamasına ve hafif yüzey üzerinde odak noktasına sahip ardışık gecikme zamanlarda radyal genleşme pozisyonları. Lazer dalga boyu: 800 nm; darbe süresi: 100 fs; güç yoğunluğu: 4.2 × 10 14 W / cm 2; hedef: Cu. <img alt="Şekil 5," src="/files/ftp_upload/4033/4033fig5.jpg" /> Şekil 5. Biraz yüzeyin altında odak noktasına sahip ardışık gecikme zamanlarda Plazma boyuna ve radyal genişleme pozisyonları. Lazer dalga boyu: 800 nm; darbe süresi: 100 fs; güç yoğunluğu: 4.2 × 10 14 W / cm 2; hedef: Cu. Şekil 6. Biraz yüzeyinden odak noktasına sahip 70 ps bir gecikme süresi içinde ölçülen ve hesaplanan plazma genişleme Animasyon. Lazer dalga boyu: 800 nm; darbe süresi: 100 fs; güç yoğunluğu: 4.2 × 10 14 </sup&gt; W / cm 2; hedef: Cu. <a href="http://www.jove.com/files/ftp_upload/4033/4033movie6.avi" target="_blank">animasyonu görmek için buraya tıklayın</a> . Şekil 7. Biraz yüzeyin altında odak noktasına sahip 70 ps bir gecikme süresi içinde ölçülen ve hesaplanan plazma genişleme Animasyon. Lazer dalga boyu: 800 nm; darbe süresi: 100 fs; güç yoğunluğu: 4.2 × 10 14 W / cm 2; hedef: Cu. <a href="http://www.jove.com/files/ftp_upload/4033/4033movie7.avi" target="_blank">animasyonu görmek için buraya tıklayın</a> . Şekil 8. Biraz yüzeyinden odak noktasına sahip 1 ps bir gecikme süresi içinde ölçülen ve hesaplanan plazma genişleme Animasyon. Lazer dalga boyu: 800 nm; darbe süresi: 100 fs; güç yoğunluğu: 4.2 × 10 14 W / cm 2; hedef:. Cu <a href="http://www.jove.com/files/ftp_upload/4033/4033movie8.avi" target="_blank">animasyonu görmek için buraya tıklayın &lt;</a>/ A&gt;.

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V., Danielius, R., Piskarskas, A., Tamoshauskas, G., Dausinger, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparative+study+of+the+ablation+of+materials+by+femtosecond+and+pico-+or+nanosecond+laser+pulses.">Comparative study of the ablation of materials by femtosecond and pico- or nanosecond laser pulses.</a> Quantum Electron. 29, 724-728 (1999).</li><li>Dausinger, F., Hügel, H., Konov, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Micro-machining+with+ultrashort+laser+pulses:+From+basic+understanding+to+technical+applications.">Micro-machining with ultrashort laser pulses: From basic understanding to technical applications.</a> Proc. SPIE. 5147, 106-115 (2003).</li><li>Hu, W., Shin, Y. C., King, G. 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Çıkar çatışması ilan etti.

Bu yazıda sunulan ölçüm ve simülasyon yöntemleri erken plazma dinamikleri ve hava ve hem Cu için iyonlaşma mekanizmaların daha iyi anlaşılması daha doğru sınavları etkinleştirin. Yüksek kalitede plazma yapılar 1 ps ve 1 mikron mekansal çözünürlükte bir zamansal çözünürlüğe sahip yakalanır. Bu ölçüm çok yüksek bir tekrarlanabilirlik sahiptir. Kritik prosedürü çok iyi ışını hizalamak ve yüksek bir düzlemsellik gibi bir düşük pürüzlülüğü sahip bir hedef yüzey hazırlamaktır. Bu yaklaşım, diğer hedef malzeme ve çeşitli parametreleri laser uygulanabilir. Pompa-sonda shadowgraph yöntemin tek sınırlaması çok düşük bir elektron sayı yoğunluğu çeşididir.

<table border="1"><tbody><tr><td> Ekipman Adı </td><td> Şirket </td><td> Katalog numarası </td></tr><tr><td> Lazer </td><td> Spectra-Fizik </td><td> SPTF-100F-1K-1P </td></tr><tr><td> ICCD Kamera </td><td> Princeton Aletleri </td><td> 7467-0028 </td></tr><tr><td> Osiloskop </td><td> Rigol </td><td> DS1302CA </td></tr><tr><td> Fotodiyot </td><td> Newport </td><td> 818-BB30 </td></tr><tr><td> Doğrusal sahne </td><td> Newport </td><td> 433 </td></tr><tr><td> Göstergesi Dial </td><td> Mitutoyo </td><td> ID-C112E </td></tr></tbody></table>

investigation of early plasma evolution induced by ultrashort laser pulses

Erken plazma hedef yüksek yoğunluklu lazer ışını ve daha sonra hedef malzeme iyonizasyon sayesinde oluşturulmaktadır. Onun dinamikleri, özellikle hava ortamında 1-11 yılında, lazer-malzeme etkileşim önemli bir rol oynar. Erken plazma evrim pompa-sonda shadowgraphy 1-3 ve interferometri 1,4-7 aracılığıyla esir olmuştur. Bununla birlikte, çalışma zaman dilimleri ile uygulanan laser parametre aralıklarını sınırlıdır. Örneğin, lazer darbeli zirve ile ilgili olarak 100 pikosaniye (PS) bir gecikme süresinden sonra plazma önünde yer numarası ve elektron yoğunluğu doğrudan incelemeler, özellikle 100 femtosecond etrafında bir süre ultrashort puls (FS) için, yine çok azdır ve 10 14 W / cm 2 civarında düşük güç yoğunluğu. Bu koşullar altında elde Erken plazma sadece yüksek zamansal ve mekansal çözünürlüklerde 12 ile son zamanlarda esir olmuştur. Ayrıntılı kurulum stratejisi veBu yüksek hassasiyetli ölçüm prosedürler bu yazıda tarif edilecektir. Ölçüm mantığı optik pompa-sonda shadowgraphy şudur: aralarındaki gecikme zamanı kendi ışın yolu uzunlukları değiştirilerek ayarlanabilir iken bir ultrashort lazer darbe, bir pompa nabız ve bir sonda darbe bölünür. Pompa darbe hedef ablates ve erken plazma oluşturur ve prob darbe plazma bölge üzerinden yayılırlar ve elektron sayı yoğunluğu olmayan tekdüzelik algılar. Ayrıca, animasyonlar Ref simülasyon modeli hesaplanan sonuçlar kullanılarak üretilir. 12 çok yüksek bir çözünürlük (0.04 ~ 1 ps) ile plazma oluşumu ve evrimi göstermek için. Deney yöntemi ve simülasyon yöntem hem zaman dilimleri ve lazer parametreleri, geniş bir aralık uygulanabilir. Bu yöntemler, metallerden, fakat, aynı zamanda yarı iletken ve izolatörleri den sadece oluşturulan erken plazma incelemek için kullanılabilir.

Watch this Scientific Journal Video about Investigation of Early Plasma Evolution Induced by Ultrashort Laser Pulses at JoVE.com

Investigation of Early Plasma Evolution Induced by Ultrashort Laser Pulses

Ultrashort lazer darbeleri ile tetiklenen erken plazma evrimini incelemek için deneysel bir yöntem tarif edilmiştir. Bu yöntemi kullanarak, erken plazma yüksek kaliteli görüntüler yüksek zamansal ve mekansal çözünürlüklerde elde edilir. Bir romanı entegre atomistik modelin erken plazma mekanizmaları taklit ve açıklamak için kullanılır.

Erken Plazma Evrim Araştırılması ultrashort Lazer Bakliyat Bağlı

Early plasma is generated owing to high intensity laser irradiation of target and the subsequent target material ionization. Its dynamics plays a ...

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14.8K Görüntüleme.  Purdue University. Ultrashort lazer darbeleri ile tetiklenen erken plazma evrimini incelemek için deneysel bir yöntem tarif edilmiştir. Bu yöntemi kullanarak, erken plazma yüksek kaliteli görüntüler yüksek zamansal ve mekansal çözünürlüklerde elde edilir. Bir romanı entegre atomistik modelin erken plazma mekanizmaları taklit ve açıklamak için kullanılır.

Video: Investigation of Early Plasma Evolution Induced by Ultrashort Laser Pulses

Fabrication of Nano-engineered Transparent Conducting Oxides by Pulsed Laser Deposition

Nanosecond Pulsed Laser Deposition (PLD) in the presence of a background gas allows the deposition of metal oxides with tunable morphology, structure, density and stoichiometry by a proper control of the plasma plume expansion dynamics. Such versatility can be exploited to produce nanostructured films from compact and dense to nanoporous characterized by a hierarchical assembly of nano-sized clusters. In particular we describe the detailed methodology to fabricate two types of Al-doped ZnO (AZO) films as transparent electrodes in photovoltaic devices: 1) at low O2 pressure, compact films with electrical conductivity and optical transparency close to the state of the art transparent conducting oxides (TCO) can be deposited at room temperature, to be compatible with thermally sensitive materials such as polymers used in organic photovoltaics (OPVs); 2) highly light scattering hierarchical structures resembling a forest of nano-trees are produced at higher pressures. Such structures show high Haze factor (&gt;80%) and may be exploited to enhance the light trapping capability. The method here described for AZO films can be applied to other metal oxides relevant for technological applications such as TiO2, Al2O3, WO3 and Ag4O4.

We describe the experimental method to deposit nanostructured oxide thin films by nanosecond Pulsed Laser Deposition (PLD) in the presence of a background gas. By using this method Al-doped ZnO (AZO) films, from compact to hierarchically structured as nano-tree forests, can be deposited.

Fabrikasyon Pulsed Lazer Biriktirme tarafından Transparent letken Oksitler Nano-mühendislik

Nanosecond Pulsed  Laser Deposition (PLD) in the presence of a background gas allows the deposition  of metal oxides with tunable morphology, structure, ...

Mühendislik

Laser-induced Breakdown Spectroscopy: A New Approach for Nanoparticle's Mapping and Quantification in Organ Tissue

Emission spectroscopy of laser-induced plasma was applied to elemental analysis of biological samples. Laser-induced breakdown spectroscopy (LIBS) performed on thin sections of rodent tissues: kidneys and tumor, allows the detection of inorganic elements such as (i) Na, Ca, Cu, Mg, P, and Fe, naturally present in the body and (ii) Si and Gd, detected after the injection of gadolinium-based nanoparticles. The animals were euthanized 1&#160;to 24 hr&#160;after intravenous injection of particles. A two-dimensional scan of the sample, performed using a motorized micrometric 3D-stage, allowed the infrared laser beam exploring the surface with a lateral resolution less than 100 &#956;m. Quantitative chemical images of Gd element inside the organ were obtained with sub-mM sensitivity. LIBS offers a simple and robust method to study the distribution of inorganic materials without any specific labeling. Moreover, the compatibility of the setup with standard optical microscopy emphasizes its potential to provide multiple images of the same biological tissue with different types of response:&#160;elemental, molecular, or cellular.

Laser-induced Breakdown Spectroscopy: A New Approach for Nanoparticle&#039;s Mapping and Quantification in Organ Tissue

Laser-induced breakdown spectroscopy performed on thin organ and tumor tissue successfully detected natural elements and artificially injected gadolinium (Gd), issued from Gd-based nanoparticles. Images of chemical elements reached a resolution of 100 &#956;m and quantitative sub-mM sensitivity. The compatibility of the setup with standard optical microscopy emphasizes its potential to provide multiple images of a same biological tissue.

Lazer kaynaklı Arıza Spektroskopisi: Organ Doku Nanopartikülün en Mapping ve Nicelik için Yeni Bir Yaklaşım

Emission spectroscopy of laser-induced plasma was applied to elemental analysis of biological samples. Laser-induced breakdown spectroscopy (LIBS) ...

Laser-induced Forward Transfer for Flip-chip Packaging of Single Dies

Flip-chip (FC) packaging is a key technology for realizing high performance, ultra-miniaturized and high-density circuits in the micro-electronics industry. In this technique the chip and/or the substrate is bumped and the two are bonded via these conductive bumps. Many bumping techniques have been developed and intensively investigated since the introduction of the FC technology in 19601 such as stencil printing, stud bumping, evaporation and electroless/electroplating2. Despite the progress that these methods have made they all suffer from one or more than one drawbacks that need to be addressed such as cost, complex processing steps, high processing temperatures, manufacturing time and most importantly the lack of flexibility. In this paper, we demonstrate a simple and cost-effective laser-based bump forming technique known as Laser-induced Forward Transfer (LIFT)3. Using the LIFT technique a wide range of bump materials can be printed in a single-step with great flexibility, high speed and accuracy at RT. In addition, LIFT enables the bumping and bonding down to chip-scale, which is critical for fabricating ultra-miniature circuitry.

We demonstrate the use of the Laser-induced Forward Transfer (LIFT) technique for flip-chip assembly of optoelectronic components. This approach provides a simple, cost-effective, low-temperature, fast and flexible solution for fine-pitch bumping and bonding on chip-scale for achieving high-density circuits for optoelectronic applications.

Tek Dies Flip-çip Ambalaj Lazer kaynaklı İleri Transferi

Flip-chip (FC) packaging is a key technology for realizing high performance, ultra-miniaturized and high-density circuits in the micro-electronics ...

Selective Area Modification of Silicon Surface Wettability by Pulsed UV Laser Irradiation in Liquid Environment

The wettability of silicon (Si) is one of the important parameters in the technology of surface functionalization of this material and fabrication of biosensing devices. We report on a protocol of using KrF and ArF lasers irradiating Si (001) samples immersed in a liquid environment with low number of pulses and operating at moderately low pulse fluences to induce Si wettability modification. Wafers immersed for up to 4 hr in a 0.01% H2O2/H2O solution did not show measurable change in their initial contact angle (CA) ~75&#176;. However, the 500-pulse KrF and ArF lasers irradiation of such wafers in a microchamber filled with 0.01% H2O2/H2O solution at 250 and 65 mJ/cm2, respectively, has decreased the CA to near 15&#176;, indicating the formation of a superhydrophilic surface. The formation of OH-terminated Si (001), with no measurable change of the wafer&#8217;s surface morphology, has been confirmed by X-ray photoelectron spectroscopy and atomic force microscopy measurements. The selective area irradiated samples were then immersed in a biotin-conjugated fluorescein-stained nanospheres solution for 2 hr, resulting in a successful immobilization of the nanospheres in the non-irradiated area. This illustrates the potential of&#160;the method for selective area biofunctionalization and fabrication of advanced Si-based biosensing architectures. We also describe a similar protocol of irradiation of wafers immersed in methanol (CH3OH) using ArF laser operating at pulse fluence of 65 mJ/cm2 and in situ formation of a strongly hydrophobic surface of Si (001) with the CA of 103&#176;. The XPS results indicate ArF laser induced formation of Si&#8211;(OCH3)x compounds responsible for the observed hydrophobicity. However, no such compounds were found by XPS on the Si surface irradiated by KrF laser in methanol, demonstrating the inability of the KrF laser to photodissociate methanol and create -OCH3 radicals.

We report on a process of in situ alteration of HF treated Si (001) surface into a hydrophilic or hydrophobic state by irradiating samples in microfluidic chambers filled with&#160;H2O2/H2O solution (0.01%-0.5%) or methanol solutions using pulsed UV laser of a relative low pulse fluence.

Sıvı Ortamda Darbeli UV Lazer Radyasyonla Silikon Yüzey Islanabilirliği Seçici Alan Değişikliği

The wettability of silicon (Si) is one of the important parameters in the technology of surface functionalization of this material and fabrication of ...

How to Ignite an Atmospheric Pressure Microwave Plasma Torch without Any Additional Igniters

This movie shows how an atmospheric pressure plasma torch can be ignited by microwave power with no additional igniters. After ignition of the plasma, a stable and continuous operation of the plasma is possible and the plasma torch can be used for many different applications. On one hand, the hot (3,600 K gas temperature) plasma can be used for chemical processes and on the other hand the cold afterglow (temperatures down to almost RT) can be applied for surface processes. For example chemical syntheses are interesting volume processes. Here the microwave plasma torch can be used for the decomposition of waste gases which are harmful and contribute to the global warming but are needed as etching gases in growing industry sectors like the semiconductor branch. Another application is the dissociation of CO2. Surplus electrical energy from renewable energy sources can be used to dissociate CO2 to CO and O2. The CO can be further processed to gaseous or liquid higher hydrocarbons thereby providing chemical storage of the energy, synthetic fuels or platform chemicals for the chemical industry. Applications of the afterglow of the plasma torch are the treatment of surfaces to increase the adhesion of lacquer, glue or paint, and the sterilization or decontamination of different kind of surfaces. The movie will explain how to ignite the plasma solely by microwave power without any additional igniters, e.g., electric sparks. The microwave plasma torch is based on a combination of two resonators &#8212; a coaxial one which provides the ignition of the plasma and a cylindrical one which guarantees a continuous and stable operation of the plasma after ignition. The plasma can be operated in a long microwave transparent tube for volume processes or shaped by orifices for surface treatment purposes.

This movie shows how an atmospheric plasma torch can be ignited by microwaves with no additional igniters and provides a stable and continuous plasma operation suitable for plenty of applications.

Nasıl herhangi bir ilave Ateşleyici olmadan bir Atmosferik Basınç Mikrodalga Plazma Torch tutuşturmak için

This movie shows how an atmospheric pressure plasma torch can be ignited by microwave power with no additional igniters. After ignition of the plasma, a ...

Automation of Mode Locking in a Nonlinear Polarization Rotation Fiber Laser through Output Polarization Measurements

When a laser is mode-locked, it emits a train of ultra-short pulses at a repetition rate determined by the laser cavity length. This article outlines a new and inexpensive procedure to force mode locking in a pre-adjusted nonlinear polarization rotation fiber laser. This procedure is based on the detection of a sudden change in the output polarization state when mode locking occurs. This change is used to command the alignment of the intra-cavity polarization controller in order to find mode-locking conditions. More specifically, the value of the first Stokes parameter varies when the angle of the polarization controller is swept and, moreover, it undergoes an abrupt variation when the laser enters the mode-locked state. Monitoring this abrupt variation provides a practical easy-to-detect signal that can be used to command the alignment of the polarization controller and drive the laser towards mode locking. This monitoring is achieved by feeding a small portion of the signal to a polarization analyzer measuring the first Stokes parameter. A sudden change in the read out of this parameter from the analyzer will occur when the laser enters the mode-locked state. At this moment, the required angle of the polarization controller is kept fixed. The alignment is completed. This procedure provides an alternate way to existing automating procedures that use equipment such as an optical spectrum analyzer, an RF spectrum analyzer, a photodiode connected to an electronic pulse-counter or a nonlinear detecting scheme based on two-photon absorption or second harmonic generation. It is suitable for lasers mode locked by nonlinear polarization rotation. It is relatively easy to implement, it requires inexpensive means, especially at a wavelength of 1550 nm, and it lowers the production and operation costs incurred in comparison to the above-mentioned techniques.

A protocol to detect and automate mode locking in a pre-adjusted nonlinear polarization rotation fiber laser is presented. The detection of a sudden change in the output polarization state when mode locking occurs is used to command the alignment of an intra-cavity polarization controller in order to find mode-locking conditions.

Çıktı Polarizasyon Ölçümler aracılığıyla Doğrusal Olmayan Polarizasyon Rotasyon Fiber Lazer Mod Kilitleme Otomasyonu

When a laser is mode-locked, it emits a train of ultra-short pulses at a repetition rate determined by the laser cavity length. This article outlines a ...

Laser-induced Forward Transfer of Ag Nanopaste

Over the past decade, there has been much development of non-lithographic methods1-3 for printing metallic inks or other functional materials. Many of these processes such as inkjet3 and laser-induced forward transfer (LIFT)4 have become increasingly popular as interest in printable electronics and maskless patterning has grown. These additive manufacturing processes are inexpensive, environmentally friendly, and well suited for rapid prototyping, when compared to more traditional semiconductor processing techniques. While most direct-write processes are confined to two-dimensional structures and cannot handle materials with high viscosity (particularly inkjet), LIFT can transcend both constraints if performed properly. Congruent transfer of three dimensional pixels (called voxels), also referred to as laser decal transfer (LDT)5-9, has recently been demonstrated with the LIFT technique using highly viscous Ag nanopastes to fabricate freestanding interconnects, complex voxel shapes, and high-aspect-ratio structures. In this paper, we demonstrate a simple yet versatile process for fabricating a variety of micro- and macroscale Ag structures. Structures include simple shapes for patterning electrical contacts, bridging and cantilever structures, high-aspect-ratio structures, and single-shot, large area transfers using a commercial digital micromirror device (DMD) chip.

We demonstrate the use of the Laser-induced forward transfer technique (LIFT) for the printing of high-viscosity Ag paste. This technique offers a simple, low temperature, robust process for non-lithographically printing microscale 2D and 3D structures.

Ag Nanopaste lazer kaynaklı İleri Transferi

Over the past decade, there has been much development of non-lithographic methods1-3 for printing metallic inks or other functional materials. Many of ...

An Atmospheric Pressure Plasma Setup to Investigate the Reactive Species Formation

Non-thermal atmospheric pressure (&#39;cold&#39;) plasmas have received increased attention in recent years due to their significant biomedical potential. The reactions of cold plasma with the surrounding atmosphere yield a variety of reactive species, which can define its effectiveness. While efficient development of cold plasma therapy requires kinetic models, model benchmarking needs empirical data. Experimental studies of the source of reactive species detected in aqueous solutions exposed to plasma are still scarce. Biomedical plasma is often operated with He or Ar feed gas, and a specific interest lies in investigation of the reactive species generated by plasma with various gas admixtures (O2, N2, air, H2O vapor, etc.) Such investigations are very complex due to difficulties in controlling the ambient atmosphere in contact with the plasma effluent. In this work, we addressed common issues of &#39;high&#39; voltage kHz frequency driven plasma jet experimental studies. A reactor was developed allowing the exclusion of ambient atmosphere from the plasma-liquid system. The system thus comprised the feed gas with admixtures and the components of the liquid sample. This controlled atmosphere allowed the investigation of the source of the reactive oxygen species induced in aqueous solutions by He-water vapor plasma. The use of isotopically labelled water allowed distinguishing between the species originating in the gas phase and those formed in the liquid. The plasma equipment was contained inside a Faraday cage to eliminate possible influence of any external field. The setup is versatile and can aid in further understanding the cold plasma-liquid interactions chemistry.

An experimental setup was created for the helium-operated kHz frequency plasma jet. The setup includes a cage for the plasma power supply and jet and an in-house built reactor to monitor plasma-induced reactive species without the interference of the ambient atmosphere.

Bir Atmosfer Basıncı Plazma Kurulum Reaktif Türler Oluşumu Araştırma

Non-thermal atmospheric pressure (&#39;cold&#39;) plasmas have received increased attention in recent years due to their significant biomedical potential. ...

Fabrication of 1-D Photonic Crystal Cavity on a Nanofiber Using Femtosecond Laser-induced Ablation

We present a protocol for fabricating 1-D Photonic Crystal (PhC) cavities on subwavelength-diameter tapered optical fibers, optical nanofibers, using femtosecond laser-induced ablation. We show that thousands of periodic nano-craters are fabricated on an optical nanofiber by irradiating with just a single femtosecond laser pulse. For a typical sample, periodic nano-craters with a period of 350 nm and with diameter gradually varying from 50 - 250 nm over a length of 1 mm are fabricated on a nanofiber with diameter around 450 - 550 nm. A key aspect of such a nanofabrication is that the nanofiber itself acts as a cylindrical lens and focuses the femtosecond laser beam on its shadow surface. Moreover, the single-shot fabrication makes it immune to mechanical instabilities and other fabrication imperfections. Such periodic nano-craters on nanofiber, act as a 1-D PhC and enable strong and broadband reflection while maintaining the high transmission out of the stopband. We also present a method to control the profile of the nano-crater array to fabricate apodized and defect-induced PhC cavities on the nanofiber. The strong confinement of the field, both transverse and longitudinal, in the nanofiber-based PhC cavities and the efficient integration to the fiber networks, may open new possibilities for nanophotonic applications and quantum information science.

We present a protocol for fabricating 1-D photonic crystal cavities on subwavelength diameter silica fibers (optical nanofibers) using femtosecond laser-induced ablation.

Femtosaniye Lazer kaynaklı Ablasyonu kullanarak nanolif 1-D Fotonik Kristal Kavitenin Fabrikasyon

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

Subsurface Defect Localization by Structured Heating Using Laser Projected Photothermal Thermography

The presented method is used to locate subsurface defects oriented perpendicularly to the surface. To achieve this, we create destructively interfering thermal wave fields that are disturbed by the defect. This effect is measured and used to locate the defect. We form the destructively interfering wave fields by using a modified projector. The original light engine of the projector is replaced with a fiber-coupled high-power diode laser. Its beam is shaped and aligned to the projector&#39;s spatial light modulator and optimized for optimal optical throughput and homogeneous projection by first characterizing the beam profile, and, second, correcting it mechanically and numerically. A high-performance infrared (IR) camera is set up according to the tight geometrical situation (including corrections of the geometrical image distortions) and the requirement to detect weak temperature oscillations at the sample surface. Data acquisition can be performed once a synchronization between the individual thermal wave field sources, the scanning stage, and the IR camera is established by using a dedicated experimental setup which needs to be tuned to the specific material being investigated. During data post-processing, the relevant information on the presence of a defect below the surface of the sample is extracted. It is retrieved from the oscillating part of the acquired thermal radiation coming from the so-called depletion line of the sample surface. The exact location of the defect is deduced from the analysis of the spatial-temporal shape of these oscillations in a final step. The method is reference-free and very sensitive to changes within the thermal wave field. So far, the method has been tested with steel samples but is applicable to different materials as well, in particular to temperature sensitive materials.

This method aims at locating vertical subsurface defects. Here, we couple a laser with a spatial light modulator and trigger its video input to heat a sample surface deterministically with two anti-phased modulated lines while acquiring highly resolved thermal images. The defect position is retrieved from evaluating thermal wave interference minima.

Lazerle Projeksiyonlu Fototermal Termografi Kullanılarak Yapısal Isıtma Yöntemiyle Alt Yüzey Kusurlu Lokalizasyonu

The presented method is used to locate subsurface defects oriented perpendicularly to the surface. To achieve this, we create destructively interfering ...