Dissertations / Theses on the topic 'Laser processing technology'
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Cheng, Ho-yiu, and 鄭浩堯. "Laser source, image processing and fast imaging technology for opticalcoherence tomography." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B44519011.
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Campi, Roberta. "High performance materials and processing technology for uncooled 1.3 μm laser diodes." Doctoral thesis, KTH, Halvledarmaterial, HMA, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-529.
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This thesis investigates different material systems and processing technology for high temperature compatible laser diodes used in volume applications within the 1.3-μm telecom wavelength window. Laser diodes built from such materials are much desired in order to eleminate the need for active temperature control needed in current systems, which significantly increases both complexity, size and cost. The structures were grown by Metal-Organic Chemical Vapor Deposition (MOCVD) and the evaluation of materials was performed using different characterization methods such as High-Resolution X-Ray Diffraction (HR-XRD), Photoluminescence (PL), Time-Resolved Photoluminescence (TR-PL). Fabrication and evaluation of Fabry-Perot lasers with different geometries was used to check the material quality and temperature performance. A novel in-situ etching technique was developed for the use i future more advanced, buried hetrostructure lasers. The first studied materials system was AlGaInAsP/InGaAsP/InP. To handle a 5-element material with the precision required, modelling of the materials and heterostructure properties was performed. The addition of Al to the InGaAsP barrier allows better electron confinement with little change in valence band properties. The optimum aluminium content was found to be about 12%. Although the effect of Al could be identified, it was not sufficient with T0 of only 90 K only up to 60 °C. A second materials system InGaP/InAsP/ InP initially looked quite promising from a materials and quantum well design point of view but encountered severe problems with the device integration and further work was discontinued. The main effort was therefore was devoted to a third materials system: AlGaInAs/AlGaInAs/InP. This material system is not unknown but has hitherto not found a widespread application for fibre optic applications. In this work, the MOCVD growth of 1.3 μ;m quantum well laser structures was optimized and ridge waveguide laser devices with excellent temperature performance was fabricated (T0 = 97 K at 85 °C). A ridge waveguide laser was identified as suitable structure since it requires only a single epitaxial growth, thus avoiding the main problem of oxidation of Al based buried structures. The dynamic performance was excellent up to 110 °C and the device fabrication is highly reliable (lifetime >7000 h). This high yield uncooled ridge Fabry-Perot laser process has now been transferred to production and is applied in short length 10 Gb/s multimode links. In order to further improve the usefulness of the Al-containing materials in even higher performance devices needed in future applications developments towards fully buried heterostructure device geometry were also pursued. To overcome difficulty of oxidation of Al containing layers at the mesa walls an in-situ etching technique was implemented. Different chemistry approaches were investigated and the first results of lasers devices were reported.QC 20100930
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Campi, Roberta. "High performance materials and processing technology for uncooled 1.3 um laser diodes /." Stockholm, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-529.
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Yu, Xinren. "Pavement Surface Distress Detection and Evaluation Using Image Processing Technology." University of Toledo / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1302032254.
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Matthews, Janette. "Textiles in three dimensions : an investigation into processes employing laser technology to form design-led three-dimensional textiles." Thesis, Loughborough University, 2011. https://dspace.lboro.ac.uk/2134/9058.
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This research details an investigation into processes employing laser technology to create design-led three-dimensional textiles. An analysis of historical and contemporary methods for making three-dimensional textiles categorises these as processes that construct a three-dimensional textile, processes that apply or remove material from an existing textile to generate three-dimensionality or processes that form an existing textile into a three-dimensional shape. Techniques used in these processes are a combination of joining, cutting, forming or embellishment. Laser processing is embedded in textile manufacturing for cutting and marking. This research develops three novel processes: laser-assisted template pleating which offers full design freedom and may be applied to both textile and non-textile materials. The language of origami is used to describe designs and inspire new design. laser pre-processing of cashmere cloth which facilitates surface patterning through laser interventions in the manufacturing cycle. laser sintering on textile substrates which applies additive manufacturing techniques to textiles for the generation of three-dimensional surface patterning and structures. A method is developed for determining optimum parameters for laser processing materials. It may be used by designers for parameter selection for processing new materials or parameter modification when working across systems.
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Bhatt, Mittal Gopalbhai. "Detecting glaucoma in biomedical data using image processing /." Link to online version, 2005. https://ritdml.rit.edu/dspace/handle/1850/939.
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Olsson, Rickard. "Signal processing and high speed imaging as monitoring tools for pulsed laser welding." Licentiate thesis, Luleå tekniska universitet, Produkt- och produktionsutveckling, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-26555.
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In Laser Materials Processing there has always been a need for suitable methods to supervise and monitor the processes on line, to ensure correct production quality or to trigger alarms when failures are detected. Numerous investigations have been made in this field, including experimental and theoretical work. It is common practice in this field to monitor surface temperature, plasma radiation and back-reflected laser light, coaxially with the laser beam. Traditionally, the monitoring systems involved carry out no statistical analysis of the signals received - they merely involve thresholds. This thesis looks at the feedback collected during laser welding using such a co-axial setup from a Digital Signal Processing point of view and also uses high speed video photography to correlate signal perturbations with process anomalies.Modern Digital Signal Processing techniques such as Kalman filtering, Principal Component Analysis and Cluster Analysis have been applied to the measurement data and have generated new ways to describe the weld behaviour using parameters such as reflected pulse shape. The limitations of commercially available welding supervision systems have been studied and design suggestions for the next generation of on line weld monitoring equipment have been formulated.Godkänd; 2009; 20091103 (ricols); LICENTIATSEMINARIUM Ämnesområde: Produktionsutveckling/Manufacturing Systems Engineering Examinator: Professor Alexander Kaplan, Luleå tekniska universitet Tid: Onsdag den 16 december 2009 kl 13.00 Plats: E 232, Luleå tekniska universitet
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Akiwowo, Kerri. "Digital laser-dyeing : coloration and patterning techniques for polyester textiles." Thesis, Loughborough University, 2015. https://dspace.lboro.ac.uk/2134/19180.
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This research explored a Digital Laser Dye (DLD) patterning process as an alternative coloration method within a textile design practice context. An interdisciplinary framework employed to carry out the study involved Optical Engineering, Dyeing Chemistry, Textile Design and Industry Interaction through collaboration with the Society of Dyers and Colourists. In doing so, combined creative, scientific and technical methods facilitated design innovation. Standardized polyester (PET) knitted jersey and plain, woven fabrics were modified with CO2 laser technology in order to engineer dye onto the fabric with high-resolution graphics. The work considered the aesthetic possibilities, production opportunities and environmental potential of the process compared to traditional and existing surface design techniques. Laser-dyed patterns were generated by a digital dyeing technique involving CAD, laser technology and dye practices to enable textile coloration and patterning. An understanding of energy density was used to define the tone of a dye in terms of colour depth in relation to the textile. In doing so, a system for calibrating levels of colour against laser energy in order to build a tonal image was found. Central to the investigation was the consideration of the laser beam spot as a dots-per-inch tool, drawing on the principles used in digital printing processes. It was therefore possible to utilise the beam as an image making instrument for modifying textile fibres with controlled laser energy. Qualitative approaches employed enabled data gathering to incorporate verbal and written dialogue based on first-hand interactions. Documented notes encompassed individual thought and expression which facilitated the ability to reflect when engaged in practical activity. As such, tacit knowledge and designerly intuition, which is implicit by nature, informed extended design experiments and the thematic documentation of samples towards a textile design collection. Quantitative measurement and analysis of the outcomes alongside creative exploration aided both a tacit understanding of, and ability to control processing parameters. This enabled repeatability of results parallel to design development and has established the potential to commercially apply the technique. Sportswear and intimate apparel prototypes produced in the study suggest suitable markets for processing polyester garments in this way.
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Lindell, David. "Process Mapping for Laser Metal Deposition of Wire using Thermal Simulations : A prediction of material transfer stability." Thesis, Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-85474.
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Additive manufacturing (AM) is a quickly rising method of manufacturing due to its ability to increase design freedom. This allows the manufacturing of components not possible by traditional subtractive manufacturing. AM can greatly reduce lead time and material waste, therefore decreasing the cost and environmental impact. The adoption of AM in the aerospace industry requires strict control and predictability of the material deposition to ensure safe flights. The method of AM for this thesis is Laser Metal Deposition with wire (LMD-w). Using wire as a feedstock introduces a potential problem, the material transfer from the wire to the substrate. This requires all process parameters to be in balance to produce a stable deposition. The first sign of unbalanced process parameters are the material transfer stabilities; stubbing and dripping. Stubbing occurs when the energy to melt the wire is too low and the wire melts slower than required. Dripping occurs when too much energy is applied and the wire melts earlier than required. These two reduce the predictability and stability that is required for robust manufacturing. Therefore, the use of thermal simulations to predict the material transfer stability for LMD-w using Waspaloy as the deposition material has been studied. It has been shown that it is possible to predict the material transfer stability using thermal simulations and criterions based on preexisting experimental data. The criterion for stubbing checks if the completed simulation result produces a wire that ends below the melt pool. For dripping two criterions shows good results, the dilution ratio is a good predictor if the tool elevation remains constant. If there is a change in tool elevation the dimensionless slenderness number is a better predictor. Using these predictive criterions it is possible to qualitatively map the process window and better understand the influence of tool elevation and the cross-section of the deposited material.Additiv tillverkning (AT) är en kraftigt växande tillverkningsmetod på grund av sin flexibilitet kring design och möjligheten att skapa komponenter som inte är tillverkningsbara med traditionell avverkande bearbetning. AT kan kraftigt minska tid- och materialåtgång och på så sett minskas kostnader och miljöpåverkan. Införandet av AT i flyg- och rymdindustrin kräver strikt kontroll och förutsägbarhet av processen för att försäkra sig om säkra flygningar. Lasermetalldeponering av tråd är den AT metod som hanteras i denna uppsats. Användandet av tråd som tillsatsmaterial skapar ett potentiellt problem, materialöverföringen från tråden till substratet. Detta kräver att alla processparametrar är i balans för att få en jämn materialöverföring. Är processen inte balanserad syns detta genom materialöverföringsstabiliteterna stubbning och droppning. Stubbning uppkommer då energin som tillförs på tråden är för låg och droppning uppkommer då energin som tillförs är för hög jämfört med vad som krävs för en stabil process. Dessa två fenomen minskar möjligheterna för en kontrollerbar och stabil tillverkning. På grund av detta har användandet utav termiska simuleringar för att prediktera materialöverföringsstabiliteten för lasermetalldeponering av tråd med Waspaloy som deponeringsmaterial undersökts. Det har visat sig vara möjligt att prediktera materialöverföringsstabiliteten med användning av termiska simuleringar och kriterier baserat på tidigare experimentell data. Kriteriet för stubbning kontrolleras om en slutförd simulering resulterar i en tråd som når under smältan. För droppning finns två fungerande kriterier, förhållandet mellan svetshöjd och penetrationsdjup om verktygshöjden är konstant, sker förändringar i verktygshöjden är det dimensionslös ”slenderness” talet ett bättre kriterium. Genom att använda dessa kriterier är det möjligt att kvalitativt kartlägga processfönstret och skapa en bättre förståelse för förhållandet mellan verktygshöjden och den deponerade tvärsnittsarean.
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Hostinský, Michal. "Nekonvenční technologie výroby řetězů." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2015. http://www.nusl.cz/ntk/nusl-232064.
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Unconventional technologies and their continual development brings along new possibilities in the manufacturing process. The submitted project is focused on solving problems in the procession of sheet metals in the manufacture of special parts of roller and conveyor chains. In the assessment of the technology of components, laser cutting was evaluated as the most optimal technology. With this goal, there was a public tender in terms of the purchase of a new machine designed for the manufacturing operations of the company of RETEZY Vamberk. This company ranks among the most major manufacturers of conveyor, roller and special chains in Europe.
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Roxner, Evelina, and Baumeister Ronja Olsmats. "Processing of Sub-micrometer Features for Rear Contact Passivation Layer of Ultrathin Film Solar Cells Using Optical Lithography." Thesis, International Iberian Nanotechnology Laboratory, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-388779.
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Thin film copper, indium, gallium, selenide (CIGS) solar cells are promising in the field of photovoltaic technology. To reduce material and fabrication cost, as well as increasing electrical properties of the cell, research is ongoing towards ultra-thin film solar cells (absorption layer thickness less than 500 nm). Ultra-thin CIGS solar cells has shown a decrease in interface recombination and improved optical properties when adding a rear contact passivation layer of aluminium oxide. In this work, the process of creating sub-micrometer features of a passivation layer using conventional optical lithography is investigated. To specify, the objective was to optimize the development conditions in the optical lithography process when fabricating equidistant line contacts in aluminium oxide with 800 nm feature size. It was found that line contacts with smaller feature sizes require longer development time, than line contacts with larger feature sizes. The experiments conducted showed that the pre-set development and exposure conditions used by the NOA group are not optimized for 800 nm or smaller line contacts. Further, for the optical lithography process, silicon substrates are not comparable with substrates of soda lime glass coated with molybdenum. Slight underdevelopment of a sample, showed line contacts smaller than the resolution of the laser used in the exposure – suggesting an alternative method of processing small line contacts with optical lithography.
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Badokhon, Alaa. "An Adaptable, Fog-Computing Machine-to-Machine Internet of Things Communication Framework." Case Western Reserve University School of Graduate Studies / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=case1492450137643915.
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Colson, Louis. "Conception et réalisation d'un dosimètre opérationnel pour la chirurgie interventionnelle assistée par radioscopie X." Thesis, Normandie, 2021. http://www.theses.fr/2021NORMC208.
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Cette thèse concerne la conception d’un dosimètre opérationnel pour les chirurgiens opérant sous rayonnement X. Les rayons X ont été découverts en 1895 par Wilhelm Röntgen. Depuis, ils sont très largement employés que ce soit pour les contrôles effectués dans les aéroports ou dans le domaine médical. Très utiles pour soigner les personnes, ils ne sont pas sans danger que ce soit pour les patients ou les praticiens hospitaliers. Normalement, les patients sont soumis de manière ponctuelle à des irradiations. En revanche, certains praticiens hospitaliers sont confrontés aux irradiations au quotidien. On distingue ici, les personnels orientés « radiographie », qui sont normalement protégés lors de l’irradiation du patient, de certains chirurgiens qui utilisent les rayons X comme moyen de contrôle durant l’opération et pour laquelle ils sont à proximité de la zone irradiée. C’est à cette problématique que s’intéresse cette thèse. L’étude que nous proposons en partenariat avec le laboratoire de recherche en science du numérique GREYC et l’Ecole des Applications Militaires de l’Energie Atomique (EAMEA) située à Cherbourg, est donc destinée à concevoir et réaliser un détecteur de rayons X pour applications médicales visant à donner une information pour une faible dose et des faibles énergies. La partie simulation et validation (irradiation) s’est faite à l’EAMEA. Le reste du travail s’est déroulé au sein du laboratoire GREYC qui a acquis, depuis plusieurs années, une réelle expérience dans le domaine des capteurs.Pour cela, nous avons commencé par réaliser des simulations Monte-Carlo à l’aide du code de calcul GEANT4 afin de définir la géométrie optimale du détecteur. A la suite de ces résultats de simulation, nous avons réalisé le capteur par pulvérisation cathodique rf magnétron par dépôt successif de couches minces. La couche sensible du capteur a fait l’objet d’une caractérisation Raman dont les résultats sont comparés à la littérature. Une fois le capteur réalisé, nous avons procédé à une caractérisation sous un flux de rayonnement X émis depuis un générateur continu de rayons X. Les différents essais avec le générateur continu ont permis de développer une chaine d’acquisition du signal pour ensuite tester le capteur sous un champ de rayonnement pulsé au Centre Hospitalier Public du CotentinThis thesis concerns the design of an operational dosimeter for surgeons operating under X-rays. X-rays were discovered in 1895 by Wilhelm Röntgen. Since then, they have been very employed, whether for checks carried out at airports or in the medical field. Very useful for treating people, they are not without danger whether it is for patients or hospital practitioners. Normally, patients are subjected occasionally to irradiation. On the other hand, some hospital practitioners are confronted with daily irradiation. A distinction is made here between “radiography” for diagnostic, who are normally protected during irradiation of the patient, and certain surgeons who use X-rays as a control during the operation and for whom they are close to the irradiated area. This is the issue that this thesis is interested in. The study that we are proposing in partnership with the digital science research laboratory GREYC and the School of Military Applications of Atomic Energy (EAMEA) both located in Cherbourg, is therefore intended to design and produce an X-ray detector for medical applications aimed at giving information for low dose and low energies. The simulation and validation (irradiation)part was done at EAMEA. The rest of the work took place within the GREYC laboratory which has acquired, for several years, real experience in the field of sensors.We started by performing Monte-Carlo simulations using the GEANT4 calculation code in order to define the optimal geometry of the sensor. Following these simulation results, we produced the sensor by rf magnetron sputtering by successive deposition of thin layers. The sensitive layer of the sensor was subject to Raman characterization, the results of which were compared with the literature. Once the sensor had been produced, we carried out a characterization under a flow of X-rays emitted from a continuous X-ray generator. The various tests with the generator continued made it possible to develop a signal acquisition chain in order to test the sensor under a pulsed radiation field in the Centre Hospitalier Public du Cotentin
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Lin, Tzu Hsiang, and 林子翔. "UV laser processing technology applied heat slug research." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/ft54u4.
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碩士國立高雄大學
電機工程學系--先進電子構裝技術產業研發碩士專班
102
As the wafer technology enhanced, the devices on the wafer are getting smaller, the integration of the circuits will increase reduces the cost. As the electronic package become thinner and smaller, the high power and high speed circuit filled in small body size makes thermal problem more critical for life time. Therefore, heat slug was used to improve the thermal problem in BGA products. However, traditional die sawing encounter problem of copper burr, heat slug peeling. In this thesis, we demonstrate UV laser cutting of heat slug metal and to evaluate the parameters of UV laser cutting with the relationship of power, frequency, and speed. We shows that the UV laser cutting is effective to achieve liable cutting edge and trench of the heat slug metal.
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Hsieh, Chi-liang, and 謝其良. "UV laser processing technology applied GaAs wafer sawing reserch." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/agcvx4.
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碩士國立高雄大學
電機工程學系--先進電子構裝技術產業研發碩士專班
102
GaAs wafer is a brittle material, there are problems in traditional diamond sawing such as die cracking, edge chipping and peeling. Therefore it is important to develop an alternative solution of die sawing for GaAs related device packaging. It is known that laser cutting has advantages of high precision and through put. In this thesis we downstate the sawing of GaAs die by UV laser of 355nm . In this experiment, we study laser sawing parameter in term of laser power. vepertion rate and cutting velocity. In addition a simple model of laser cutting is proposed to evaluate the laser cutting efficiency of GaAs wafer . As a conclusion ,an optimized laser cutting parameters were achieved and is helpful to apply in GaAs related device package process.
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Wu, Po-Yi, and 吳柏嶧. "Laser Processing Technology Used in White Light-Emitting Electrochemical Cells." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/7b9m4e.
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碩士國立交通大學
光電科技學程
105
In this study, 532-nm Nd: YAG solid-state laser is employed to fabricate surface plasmonic filters. By controlling the laser pulse frequency and power, the thin silver layer on the substrate is annealed and then transform into nanoparticles. The experimental results verify that patterning by laser annealing prevents using of shadow mask in etching processes, rendering quick producing the surface patterns. The laser annealing process can also selectively anneal silver nitrate film to induce reducing process to generate silver film. By adjusting the laser energy intensity, focus point and processing time, the silver film is melted and then cooled to form silver nanoparticles. Surface plasmonic filters composed of silver nanoparticles exhibit absorption at certain spectral region. Such property can be used to adjust the color temperature of output spectrum from white light-emitting electrochemical cells.
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Chang, Yong-Xiang, and 張勇祥. "Innovative Laser Micropore Processing Technology Assisted by Breath Figure Method." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/7696ef.
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碩士國立雲林科技大學
機械工程系
107
Laser microstructure processing is achieved in the market by relying on the extremely short pulse width characteristics of ultra-fast lasers. The purpose of this study is to use a liquid micro lens array to focus the nanosecond laser onto a planar substrate, thereby forming a large area of microporous structure on the surface of the substrate. The micro-holes measured by AFM are close to the annular groove. The research is divided into two parts, one is to form a large number of liquid lens arrays on the substrate, and the other part is to use the liquid lens to assist the micro-hole processing of the nanosecond laser on the substrate.
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Knoernschild, Caleb. "Scalable Optical MEMS Technology for Quantum Information Processing." Diss., 2011. http://hdl.handle.net/10161/3846.
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Among the various physical systems considered for scalable quantum information processing (QIP), individually trapped ions or neutral atoms have emerged as promising candidates. Recent experiments using these systems have demonstrated the basic building blocks required for a useful quantum computer. In many of these experiments, precisely tuned lasers control and manipulate the quantum bit (qubit) represented in the electronic energy levels of the ion or atom. Scaling these systems to the necessary number of qubits needed for meaningful calculations, requires the development of scalable optical technology capable of delivering laser resources across an array of ions or atoms. That scalable technology is currently not available.
In this dissertation, I will report on the development, design, characterization, and implementation of an optical beam steering system utilizing microelectromechanical systems (MEMS) technology. Highly optimized micromirrors enable fast reconfiguration of multiple laser beam paths which can accommodate a range of wavelengths. Employing micromirrors with a broadband metallic coating, our system has the flexibility to simultaneously control multiple beams covering a wide range of wavelengths.
The reconfiguration of two independent beams at different wavelengths (780 and 635 nm) across a common 5x5 array of target sites is reported along with micromirror switching times as fast as 4 us. The optical design of the system minimizes residual intensity at neighboring sites to less than 40 dB below the peak intensity. Integration of a similar system into a neutral atom QIP experiment is reported where 5 individually trapped atoms are selectively manipulated through single qubit rotations with a single laser source. This demonstration represents the first application of MEMS technology in scalable QIP laser addressing.
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Ke, Wen-Ching, and 柯文卿. "A Renovated Scientific Model Using Laser Optics and Image Processing Technology." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/29760655362376065537.
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Chen, Ching Ming, and 陳晋銘. "Optical Spectrometer Analysis Technology of Laser Processing Apply to Touch Panel." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/54303257741063765680.
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碩士中華科技大學
機電光工程研究所碩士班
101
The study focus on laser optical absorption for the materials using on touch panel, including glass, or PET, and so on. The aged technology is wet processing for narrow line-width production, or screen printing processing for wild line-width production. But the wet processing is no good for pollution, and screen printing processing is not good for narrow board edge. So laser dry etching processing would be good for next generation technology, and it could have no pollution, also with narrow line-width characteristic. The experimental method is the use material spectrometer samples were Ag on PET, ITO on PET and ITO on Glass for materials analysis, analysis will be carried out for the sample material reflectivity and absorptivity test and post-test using the equation A% = 100 %-T%-R% absorption rate calculation results from the calculation of how much material that the wavelength of light absorption rate can have the best effect, and the analysis of the results for different samples to select a different laser wavelengths begin mine shot optimize processes. The results showed that Ag on PET material of the light wavelength 2700nm ~ 200nm and horses are well over 60% absorption rate, and the absorption of 500nm ~ 200nm optimal, so the material Ag on PET in the choice of the laser can be more selection. ITO on PET materials and materials ITO on Glass absorption of light in the ultraviolet best, can have 70% to 80% of the absorption effect, but when the light at 2500nm ~ 2700nm ITO on PET material of the absorption rate to be achieved 30% to 40%, so if the process requirements of different wavelength is 2500nm ~ 2700nm range can be selected.
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Wang, Xiaoliang. "Ultra-short pulsed laser surface processing and decontamination." 2008. http://hdl.rutgers.edu/1782.2/rucore10001600001.ETD.000050472.
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HUANG, YU-CHIA, and 黃昱嘉. "The Application of Deep Learning and Image Processing Technology in Laser Positioning." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/2h9k92.
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碩士逢甲大學
自動控制工程學系
106
In this study, machine vision technology is mainly used to precisely position the highest energy of the laser spot. This facilitates the subsequent joining of product workpieces in the laser welding machine. The displacement stage can place workpieces into superposition area and allow the parts to be joined. With deep learning and convolutional neural network training program, the system can enhance the accuracy of the positioning, and enhance the efficiency of the machine work. A bi-analytic deep learning localization method is proposed in this study. The camera is used for real-time monitoring. The first step is to use a convolutional neural network to perform a large-scale preliminary search to locate the laser light spot region. The second step is to increase the optical magnification of the camera, re-image the spot area, and then use the template matching to perform high-precision repositioning. According to the aspect ratio of the search result area, the integrity parameters of the target spot is determined. The centroid calculation is performed in the complete laser spot. If the target is an incomplete laser spot, the operation of invariant moments is performed. Based on the result, the precise position of the highest energy of the laser spot can be obtained from the incomplete laser spot image. The amount of displacement can be calculated for overlapping the highest energy of the laser spot and the center of the image.
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Liang, Shin-wei, and 梁辛瑋. "Optimization of Microcrystalline Silicon Thin Film Solar Cell Isolation Processing Parameters by using Laser Technology." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/45014897567083821128.
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碩士國立臺灣科技大學
自動化及控制研究所
97
The microcrystalline silicon thin film solar cell consists of several thin films, such as the microcrystalline silicon thin film, the aluminum-doped zinc oxide transparent conductive film, and aluminum back-contact thin films. The purpose of this research is to find the optimization parameters of making the several thin films isolated well by laser scribing. In this study, we used three laser systems, Ultraviolet Laser, Fibre Laser, and Femtosecond Laser, to examine the relation between factors of laser systems and the quality characteristics of laser isolation processing. By using Taguchi Method, we could obtain factors and quality characteristics from following the L18 orthogonal array to set up the experiment. We defined the quality characteristics of scribing structure, such as upper width of V-cut line, lower width of V-cut line, V-cut depth, and the burrs above processing surface of microcrystalline silicon thin film. Therefore, the optimal factors combination for isolation processing of the microcrystalline silicon thin film were conducted via Taguchi Method and analytic hierarchy process theory. The results of laser scribing microcrystalline solar cell materials are as follows: AZO(200nm) scribed a minimum line width of 16.07 micrometers, AZO(500nm) scribed a minimum line width of 17.66 micrometers, microcrystalline silicon(38% crystallinity) scribed the smallest line 24.29 micrometers wide, microcrystalline silicon(68% crystallinity) scribed a minimum line width of 29.91 micrometers, and aluminum back contact(300nm) scribed the smallest line 11.57 micrometers wide. In additions, we can predict the results of laser isolation processing through simulation experiments by using the back propagation neural computing forecasting system. Through experimenting and computing, the error between actual value and predicted value could be converged within 2%. Finally, the results of laser isolation processing experiment were confirmed.
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Chiu, Hsuan-yen, and 邱宣諺. "Research on the Optimization of the Transparent Conductive Oxide Films Processing Parameters Using Laser Technology." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/79623337603478910753.
Full textAbstract:
碩士國立臺灣科技大學
高分子系
97
The touch panel is widely used in mobile phones, cash machines, navigation systems. The transparent conductive oxide films are one of the key materials for touch panel. The processing parameters will affect the electrical conductivity of touch panel. In this study three different laser wavelengths (UV-laser wavelength of 355nm, femtosecond laser wavelength 800nm and carbon dioxide laser wavelength 10640nm) were used to cut a transparent conductive oxide films and to obtain optimal quality characteristics of transparent conductive oxide films. Taguchi method orthogonal array was applied to plan the experiment. The quality characteristics of transparent conductive oxide films, such as cutting width, heat affected zone and burrs, were chosen. Next signal-noise ratio (SN) and analysis of variance (ANOVA) were adopted to examine the significant factors for transparent conductive oxide films. Moreover, grey relational analysis and fuzzy inference system were used to get optimum conditions for multi-quality characteristics. Lastly, a predicting system was established to simulate the results of experiment by using back-propagation neural network with LM algorithm. For the results of experimental verification, it indicated that the prediction error is less than 5%. These reveal that the prediction system has good forecasting ability.
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Chen, Jian-Liang, and 陳建良. "A research on the optimization of the micro structure processing parameters using CO2 laser technology." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/70504763450420415049.
Full textAbstract:
碩士國立臺灣科技大學
高分子系
96
The light guide plate is a part of the back light module, which evenly spreads light sources in the liquid crystal display (LCD) to eliminate total reflection. Light will be transmitted into the light guide and can be reflected, scattered, and refracted due to the micro structure, which allows light to uniformly enter the panel. Therefore, designing light guide’s micro structure and production procedure is important for light transmission in the LCD. In this study, we used carbon dioxide laser to manufacture PMMA light guide in order to examine the relation between factor of carbon dioxide laser and the quality characteristic of LCD light guide. The best factor for manufacturing light guide is done via Taguchi Method, Entropy measurement and TOPSIS. We first decided quality characteristic of V-cut structure, such as dimension, degree of uniform time of production. Using those information and Taguchi Method, we could then obtain factors and quality value and then follow the orthogonal array to set up the experiment. Since the Taguchi Method focuses on single quality, we would not reach full optimization. We then added Entropy Measurement combined with TOPSIS to optimize the conditions of this manufacturing. We used signal-noise ratio (SN) and analysis of variance (ANOVA), which is in the Taguchi Method to examine the result and confer this experiment. From this analysis, we could examine the most important factor for quality of light guide. Lastly, we establish a predicting system between process parameters and quality characteristics to simulate the result of experiment by using back-propagation neural network with BFGS algorithm. Therefore, the predicting system for quality characteristics of light guide can be proved in accurate.
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Ullberg, Nathan. "Characterizing optical and electrical properties of monolayer MoS2 by backside absorbing layer microscopy." Thesis, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-419630.
Full textAbstract:
Nanomaterials are playing an increasing role in novel technologies, and it is important to develop optical methods to characterize them in situ. To that end, backside absorbing layer microscopy (BALM) has emerged as a powerful tool, being capable to resolve sub-nanometer height profiles, with video-rate acquisition speeds and a suitable geometry to couple live experiments. In the internship, several techniques involving BALM were developed, and applied to study optical and electrical properties of the transition metal dichalcogenide (TMD) monolayer MoS2, a type of 2-dimensional (2D) crystalline semiconductor. A simulations toolkit was created in MATLAB to model BALM, a workflow to reliably extract linear intensities from the CMOS detector was realized, and 2D MoS2 was synthesized by chemical vapor deposition followed by transfer to appropriate substrates. BALM data of the 2D MoS2 was acquired and combined with simulations, giving a preliminary result for its complex refractive index at 5 optical wavelengths. In addition, the first steps towards coupling BALM with a gate biased 2D MoS2 field-effect transistor were explored. To complement BALM measurements, the grown samples were also characterized by conventional optical microscopy, scanning electron microscopy, atomic force microscopy, photoluminescence spectroscopy, and Raman spectroscopy. This work provides new additions to an existing platform of BALM techniques, enabling novel BALM experiments with nanomaterial systems. In particular, it introduces a new alternative for local extraction of optical parameters and for probing of electrical charging effects, both of which are vital in the research and development of nano-optoelectronics.